Abstract
Knowledge about ability grouping exceeds knowledge of specific teaching practices within such groups. This study examines instructional practices in Czech primary schools that employ a hybrid model, combining heterogeneous classroom instruction with ability-based grouping in selected subjects. Drawing on ethnographic observations (
Keywords
Introduction
Grouping students into different schools and classes based on their abilities is a common practice in many educational systems of developed countries, including the Czech Republic. This approach is based on the belief that different students operate at different ability levels. As a result, they—as well as their teachers—should benefit from teaching in an environment that is better tailored to their needs and capacities. However, this issue has sparked debate among both experts and the public regarding the extent to which this premise holds true (Chmielewski, 2014; Francis et al., 2020; Gamoran, 2010; Straková, 2010).
Research has repeatedly shown that ability grouping tends to deepen educational inequalities rather than improve academic outcomes for all students. The greatest benefits are observed among students in high-ability groups, who, due to high expectations, better teacher attention, and an inspiring environment, acquire deeper knowledge and skills. By contrast, students in lower-ability groups often fall behind (Blanco-Varela et al., 2024; Muijs & Dunne, 2010). These differential outcomes may be partly explained by teachers’ mindsets: fixed beliefs about students’ abilities can lead to lower expectations and limited learning opportunities for lower-ability groups, while a growth mindset may foster higher expectations across all groups (Dweck, 2006). It has been demonstrated that the social backgrounds of students significantly influence their placement in specific groups. For example, students from ethnic minority backgrounds are more frequently assigned to lower-ability groups (Connolly et al., 2019), and children of parents with higher education are predominantly placed in higher-ability groups (Feniger et al., 2021).
The negative effects of this practice are leading education policymakers in developed countries to seek ways to reduce ability grouping in mainstream education and to strengthen teaching in heterogeneous groups that promote inclusion, reduce educational inequalities, and enable the development of the skills of all students, regardless of their social or cultural background. These efforts are also evident in the Czech Republic, which faces high levels of inequality due to its highly selective education system (OECD, 2023). Policies advocate limiting the permanent allocation of students to different schools within the mainstream (Fryč et al., 2020), a practice known as “tracking.” Other less visible forms of ability grouping are emerging and have not yet been systematically tracked. This study focuses on one form of ability grouping: combining heterogeneous classroom instruction with ability-based group instruction in selected subjects.
Existing research has mainly focused on the effects of ability grouping on student learning outcomes and self-confidence, and less on the actual teaching practices used by teachers in these groups (Tan & Dimmock, 2022). Thus, not enough is known about whether teachers use ability grouping to adapt their instructional practices and whether these practices are more effective in homogeneous groups or heterogeneous classrooms. The text therefore focuses on an analysis of forms of instruction – examining how instruction is designed in heterogeneous classrooms and how it differs from instruction in ability-based groups. The study asks the following research questions:
How is teaching conducted in a hybrid form of ability grouping?
How does this form address the individual needs of students in heterogeneous and homogeneous groups?
Theoretical Approach
Differentiated Instruction Through Ability Grouping
Schools can use different strategies to group students by ability. 1 In principle, they can group students at three levels: at the level of the education system, at the level of the school, and at the level of the classroom or within the classroom. At the level of the education system, students can be grouped into different schools (tracking). At the school level, they can be grouped into different classes (streaming). At the classroom level, they can be grouped into different groups (setting). This form of grouping usually only happens in selected subjects. Finally, students can group directly within the classroom (within-class grouping; Francis et al., 2020).
The possibilities for grouping students are therefore quite varied. As Taylor et al. (2022) postulated, the range may be even more varied. Different forms of student grouping can even occur simultaneously in a single school (Chmielewski, 2014). A school can offer a selective class (streaming); within that selective class, students can then be further grouped in the subject according to their level of proficiency (setting). Kelly et al. (2008) documented that many schools have classes in which students are grouped into more permanent groups for instruction in at least one subject. It might be expected that the rate of student grouping increases in higher grades.
The more permanent the grouping of students, the more controversial the model in terms of educational inequalities. The most rigid forms, such as tracking, are considered the most problematic because they can significantly affect a student’s educational trajectory at an early age and thus irreversibly contribute to widening social and educational inequalities. In contrast to more flexible forms of grouping, which allow for more differentiated instruction based on student needs and can change the group if ability levels change, rigid grouping often fixes student expectations and opportunities based on initial decisions. This not only limits future opportunities but also reflects or even reinforces socioeconomic differences among groups of students (Van de Werfhorst, 2019). Critics of rigid models also point to the risk of the so-called stigma effect, whereby students in weaker groups or schools are systematically disadvantaged both in their access to quality education and in their expectations of future success, which can affect their motivation and self-confidence.
The mechanisms through which ability grouping may perpetuate or mitigate inequalities are closely linked to teachers’ beliefs about students’ abilities and the expectations they form accordingly. Merton’s (1948) concept of the self-fulfilling prophecy provides a useful lens for understanding how teachers’ initial expectations can shape student outcomes. When teachers hold fixed beliefs about students’ abilities—what Dweck (2006) terms a “fixed mindset”—they may unconsciously communicate lower expectations to students in lower-ability groups, thereby limiting these students’ learning opportunities and reinforcing initial ability judgments. Conversely, when teachers adopt a “growth mindset” (Dweck, 2006), believing that abilities can be developed through effort and appropriate support, they are more likely to maintain high expectations for all students regardless of their group placement. This theoretical framing is critical for understanding not only
Ability grouping seems to reinforce inequalities, and the promise of more effective teaching seems to weaken. However, if schools decide to group students in a particular way for more effective teaching, it is necessary to adapt the teaching to the needs of individual students. Ability grouping itself cannot be equated or confused with differentiated instruction. The mere distribution of pupils according to ability should not be confused or equated with differentiated instruction, although several studies show that this is often what teachers mean by differentiated instruction (Gaitas et al., 2024; Graham et al., 2021). Ability grouping is merely an organizational format that can help teachers target instruction more easily to the needs of their students.
However, in line with Tomlinson (2014), I understand differentiated instruction as a teaching design in which teachers proactively adapt instruction to differently prepared students. Tomlinson’s framework emphasizes that effective differentiation goes beyond mere organizational arrangements; it requires teachers to deliberately modify content, process, product, and learning environment based on students’ readiness, interests, and learning profiles. Teachers do not only consider readiness in terms of ability and skills in the subject matter; they also consider learner interest in the subject or topic and the learning profile involving different learning styles, preferences, and support needs for completing tasks. This conceptualization of differentiated instruction served as a key analytical lens in this study, guiding the examination of whether and how teachers adapt their instructional practices across different grouping formats—whether they differentiate within ability groups or rely primarily on the homogeneity of the group as a substitute for individualized differentiation.
It follows that differentiated instruction do not arise naturally or randomly but are the result of conscious and reflective actions of schools and particularly teachers (Dixon et al., 2014; Sandoval et al., 2021). In this context, it is emphasized that both initial teacher training and continuous professional development (Walton et al., 2022; Whitley et al., 2019) play a crucial role. These aspects significantly influence how well-prepared new teachers and experienced educators feel to face the challenges of diversity in today’s classrooms.
Research shows that implementing differentiated instruction into practice is challenging for many teachers, despite sufficient theoretical knowledge (Suprayogi & Valcke, 2016). At the same time, differentiating instruction in different formats of student grouping proves more challenging, although teachers often group students precisely to make differentiating instruction easier. Research by Burris and Garrity (2008) shows that teachers differentiate instruction more in heterogeneous classrooms because the diversity of the classroom implicitly forces them to do so. In homogeneous groups, teachers are more likely to tailor instruction to the needs of the whole group, often overlooking that students’ abilities and needs may vary (see Wright & Forrester, 2025). This points to the risk that homogeneous groups may result in less flexibility in instruction and less focus on individual student needs. This paradox—that ability grouping intended to facilitate differentiation may reduce it—reflects the tension between organizational strategies and pedagogical practices and underscores the importance of examining actual teacher behaviors rather than assumed benefits of grouping structures. If teachers tailor instruction primarily to the characteristics of the group, they risk overlooking the differences and specific needs of individuals, which, moreover, may change over time. Differentiated instruction thus requires not only organizational measures such as ability grouping, but above all careful and continuous monitoring of each pupil’s abilities, interests and preferences.
Ability Grouping in the Context of Czech Lower Elementary Schools
Grouping according to ability within and between classes has been widespread in Czech lower elementary schools, especially in foreign language teaching, in which students are often divided into “more advanced” and “less advanced” groups. The higher ability groups often have extended learning opportunities, such as native speaker tuition or language stays (The Czech School Inspection, 2018). In subjects other than foreign languages, ability grouping within the classroom was rather rare in the Czech Republic until recently.
In recent years, however, lower elementary schools have started to profile themselves differently (Straková, 2021). Some schools try to show that they can meet the needs of all students more effectively through ability grouping. Other schools use ability grouping to attract potential upper elementary school students. By teaching in ability-homogeneous groups, the schools are trying to guarantee a cognitively stimulating environment for students and parents that is comparable to the challenges of an upper elementary school. Between-class ability grouping is beginning to expand students are divided into ability-homogeneous groups not only for foreign language but also for other subjects, especially Czech language and mathematics. Some schools tend to adopt a hybrid approach, combining homogeneous group teaching with heterogeneous classroom teaching. For example, students may have two lessons a week in a chosen subject in ability groups and a further two or three lessons in heterogeneous classes.
Although ability grouping is increasing in lower elementary schools, there is a lack of systematic monitoring of its forms, including analyses of forms of differentiated instruction. Lower elementary schools are experimenting with different types of ability grouping, that is, they are trying different styles and finding the most effective ways. In one study (Simonová, 2023), the authors observed how schools approach interclass grouping in foreign language, Czech language, and mathematics in selected lower elementary schools. The authors found that interclass grouping was described by both teachers and students as more effective than heterogeneous classroom teaching. At first glance, it may seem that it is better to divide the class when most of the students themselves say that they do better in groups and that teachers teach better. However, deeper analyses have shown that this view misses the voices of those students who do not do better.
Navrátilová (2019) examined the participation patterns of students in a hybrid cluster, that is, a classroom in which students were educated on some subjects both in ability-based groups and together in the classroom. She found that both high-ability and low-ability students were more active in their homogeneous groups. However, the reasons for higher participation differed between the two groups. Students in the higher ability group participated more often in communication to demonstrate their ability to their group mates; students in the lower-ability groups were more active because they were not afraid to make mistakes in this group and were not victims of ridicule from their higher-ability classmates. In addition, the data showed that all students were more comfortable in group learning, which contradicts efforts to mitigate selection mechanisms at the lower elementary level.
This suggests that other forms of ability grouping are beginning to emerge in Czech lower elementary schools and deserve research attention. A similar topic that has been neglected in the research is the teaching practices that teachers apply in different student groupings and whether these practices address the learning needs of all students. Analyses of teacher and student experiences of teaching and learning in different ability-based groups are lacking. The present study attempts to fill these research gaps by focusing on teacher strategies and practices within each grouping rather than on descriptions of structural differentiation among students.
Methodology
The study is part of a long-term research project that mapped how students are grouped in lower elementary schools in the Czech Republic during the 2018–2020 school years. The project was conceived as a multi-case study seeking to penetrate the life of five lower elementary schools and provide a holistic picture of how the model of grouping students is implemented, how differentiated teaching in groups takes place, and how this model is perceived and acted upon by the main actors in school life—school administrators, teachers, and students.
The research took place in the second cycle of lower elementary schools, specifically in the sixth grade (students aged 11–12 years). These were public, mainstream, and fully organized lower elementary schools. The average class size across all 5 schools was 27 students. The schools used the same form of ability grouping: combining heterogeneous classroom instruction with ability-based group instruction. This hybrid form was applied only in selected subjects—Czech language and mathematics. Students were educated in ability-based groups once a week; on the other days of the week, they were educated on these subjects together in a heterogeneous class. Students were divided into two ability-based groups—high-ability and low-ability—based on a placement test designed by the teachers. Besides the placement test, certain teachers considered additional factors like past grades and the former teacher’s subjective opinions. Teachers aimed to create numerically balanced groups to ensure relatively equal group sizes.
This study used data from ethnographic observations of teaching (
All collected data were anonymized. The research was conducted following ethical principles that included informed consent from all participants, voluntary participation in the investigation, and the possibility to withdraw from the research at any time without any negative consequences. Care was taken during data collection, processing, and analysis to ensure that no bias or manipulation occurred and to ensure the objectivity and credibility of the findings. The aim was to contribute to scientific knowledge while respecting the rights and dignity of all stakeholders.
Data Analysis
Given the multi-case study design, the choice of the next analytical procedure was clear. Data coding was performed in several cycles. In the first cycle, interview transcripts and field notes from observations were subjected to close reading (Emerson et al., 2011, pp. 142–143). During the reading process, the data were annotated and commented on in parallel to establish initial categories and relationships. Textual excerpts were annotated with interpretive notes to facilitate subsequent coding. Field notes were annotated mainly in paper form and transcripts were annotated in ATLAS.ti software. At this reading stage, there was a slight reduction of data – data that were not primarily related to the issue under study were color-coded.
In the second cycle, the interview data were subjected to initial coding, which is a standard procedure when beginning qualitative data analysis (Strauss & Corbin, 1998, p. 43). Individual passages were assigned codes at the most general, yet descriptive level with a lower level of induction. These codes also included so-called in vivo codes, that is, concepts taken directly from the participants (Charmaz, 2006, p. 55), for example,
Following the cycle of initial coding, the emergent codes were grouped by similarity into provisional categories. In this third, focused cycle, the categories were named more abstractly than the codes that saturated them. In parallel, the transcripts were repeatedly reviewed, and, considering the emerging categories, the original, hitherto descriptive codes were split into subcodes and progressively focused or unified. The aim of this phase was to raise the codes to a higher level of abstraction; even the category names were corrected.
In the fourth cycle, all codes and their categories were printed, cut out, and clustered in paper form into the final, most abstract categories. As Yin (2009, p. 128) states, the coding and categorization of data in the software is primarily for organizing the data and preparing it for deeper analysis.
The field diary data were analyzed in parts in several steps. The field notes were first subjected to close reading and then summarized into a few sentences after each lesson or series of lessons, as recommended by Yin (2009, p. 128). This produced indicative summaries of each data section, asking what the data were saying. The purpose of these summaries was to locate the main themes that served as a guide for subsequent coding. In the next step, the thematic units were coded using the pencil-and-paper method.
After several cycles of data coding, the cases were compared with each other. Comparison of cases was done through cross-case analysis. This analysis followed the traditional method of first analyzing each case separately before comparing them with each other (Yin, 2009, p. 156). The resulting codes, categories, and associated notes were assigned separately to each case. In the next stage, phenomena were compared first within and then between cases. The data were organized in tables according to different criteria, for example, by timeline or by the degree of inclusiveness of the differentiation strategies applied by the teachers.
Together with the cross-case analysis, the constant comparative method (Glaser & Strauss, 1967, p. 101) was applied. Following the recommendations of Charmaz (2006, p. 54 et seq.), a sequential comparison was performed: first, matches and differences within one data source were sought, then data from different sources concerning the same actor were compared, then events at different time points and locations were compared, and finally comparisons were made across different actors and cases.
This selective comparison enabled the creation of a typology of cases and the identification of specific conditions of occurrence of phenomena. For example, three variants of test tasks were identified according to their difficulty: (a) tasks with the same difficulty for all students, (b) tasks with different difficulty depending on the group, (c) a combined variant of both approaches. Furthermore, the dependence of the difficulty of the test tasks on the type of written work and on the classification, criteria was found.
This whole analytical process, involving sequential coding, categorization and cross-case analysis, was accompanied by measures aimed at ensuring the reliability of the interpretations and the trustworthiness of the results. Coding reliability was ensured in several ways. First, after the first coding cycle was completed, a random sample of data (15%) was selected and re-coded 4 weeks apart. Agreements and differences between the two codings were identified and based on this comparison, those codes that showed inconsistencies were refined and adjusted. Second, reliability was increased by systematic triangulation of data sources—categories derived from interviews were compared with data from field observations. Third, all analytical decisions were continuously documented in ATLAS.ti software, allowing for retrospective review of the entire analytical process.
Findings
Cross-Case Patterns in Teaching Practices
Before presenting the detailed findings, it is important to note that the analysis was conducted with attention to potential differences across the multiple classroom settings included in this study. Initially, I anticipated that variations in teaching practices might emerge based on teacher experience, school context, or student composition. However, the data revealed striking consistency across all cases.
The patterns described below—reliance on frontal teaching in mixed-ability settings, use of ability grouping for differentiation, and mismatches between teacher support and student needs—were evident in all observed classrooms. While minor variations existed (e.g. specific activities chosen by teachers), the underlying structure and logic of teaching remained uniform across cases. This consistency suggests that the practices observed reflect systemic features of ability grouping rather than individual teacher preferences.
Given this cross-case uniformity, the findings are presented thematically rather than case-by-case. This unexpected consistency is itself a significant finding, indicating that the challenges identified may be structurally embedded in the organizational model of ability grouping.
Teaching Practices in Mixed-Ability Classrooms
Teaching in the heterogeneous classroom is based on frontal practice of the curriculum. This pattern was consistent across all observed classrooms. “It’s just a classic frontal classroom where I explain the new curriculum to the students, then we write it down together in a notebook, and if it goes well, we catch up on a few examples, but nothing more, the lessons are the same,” said Nicole (teacher). The structure and focus of the mixed-ability lessons were also reported by students in the interviews: “The teacher usually explains new things there, or we do exercises from the textbook in the notebook,” said Christine (student). Martin (student) noted the patterned teaching in the mixed-ability lessons, saying: “It’s the same thing over and over again.” The bulk of the mixed-ability teaching took place through a combination of frontal teaching and independent work by the students. Rarely did teachers deviate from these forms, and student responses indicate that the repetitive nature of the teaching did not appeal to them very much.
The pitfall of frontal teaching is that it makes it difficult to create space for an individual approach. This statement can be illustrated by excerpts from teacher interviews. “By being frontal, it’s obvious that it’s going to miss someone. I can see for myself that the better ones get bored a lot of times and the slower ones drown a bit, but it’s just the half hours that save it,” said Sidney (teacher). Mass presentation of the material to the whole class risks making the explanation too difficult for the lower-ability students and too easy for the higher ability. Teaching in ability-based groups is seen by teachers as a lifeline to pull students up from the bottom.
The need for a more individual approach to collaborative learning was reflected by all the students in the interviews across all settings. Students otherwise belonging to the lower-ability group expressed a desire for more attention from teachers. This was evidenced in this statement from Eric (student), “Like sometimes I don’t perceive, and I don’t really understand what the teacher is saying, it’s fast sometimes and like sometimes I don’t have time to write it down and when I say so the teacher immediately says there’s no time.” In contrast, students otherwise belonging to the higher-ability group usually understand the material, complaining rather about the monotonous way in which the material was presented. This was evidenced by testimony from Francis (student): “When we do something new, like in math, I kind of enjoy it, but I don’t enjoy it in normal classes because we spend the whole hour writing in a notebook or waiting for others to finish something.” Francis did not mind that new material was discussed in the mixed-ability lessons, but rather that most of the lesson was devoted to writing down what was said or to mass practice, which different students completed the tasks at different times. Naturally, such a situation is not to the liking of those students who complete the exercises in advance and must wait for the rest of the time for everyone else to complete the task. Observational data indicated that students who completed the work ahead of time would benefit from additional but stimulating activities. When the fastest students completed the work, they waited for the other students in a variety of ways: they helped other students with the teacher’s prompting, they finished their own homework for other subjects, they passed the time by going to the toilet, or they simply did nothing, lounging around the classroom and seeking distraction with their classmates sitting at nearby desks.
These situations led me to the idea of asking the students how they would like to fill the time when they were waiting for others. The students answered quite specifically, “I would like to count some examples from Pangea 2 or do something interesting, but this is just boring,” said Francis (student). Ann (student) offered a similar answer: “I would like to do some thinking problems, for extra points, like for a little A or something.” These student responses illustrate that their faster working pace essentially disadvantages them in the mixed-ability classes. These students resent their time being spent wastefully. In their interviews, they offered specific suggestions for activities they would like to fill their free time with.
However, the teachers in all participating classrooms were clear about the possibility of an individual or differentiated approach to students in the common lessons: “There is no chance, the number of students will not allow you to individualize, that is what the groups are for. I will find out at the blackboard how everyone is doing and what needs to be worked on,” said Catherine (teacher).
The fact that teachers find it easier in differentiated teaching to find out how much students understand and can address student needs individually was confirmed by other teachers. For example, Clara (teacher) stated: When you have fewer students, you can pay more attention to them and check their work when you give them an assignment. That way you can go around all of them several times and you can immediately see who doesn’t know what they are doing and you have time to help them. It is 50% more efficient than if you have a whole class of course, so I look forward to those groups, I rely on them to be able to do both groups.
The citations suggest a rather strong finding. At first glance, it seems that teachers enter teaching in a heterogeneous classroom knowing that they are not able to respond as well to student learning needs as they do in ability groups; they perceive ability groups as being directly designed for such practices. However, the data are more indicative of teachers resigning themselves to relying on ability groups. It seems as if teaching in ability groups is replacing what teachers should also be trying to do in mixed-ability groups. The fact that the satisfaction of different learning expectations occurs more effectively in ability groups reduces teacher efforts to create conditions for individual student access and the overall implementation of differentiation strategies in the heterogeneous classroom. Thus, it can be stated with some caution that the possibility of homogeneous grouping devalues the quality of teaching in a heterogeneous classroom.
Teaching Practices in Ability Groups
In a heterogeneous classroom, teaching is based on frontal practice of the material. Differentiated and individualized practices appear only sporadically in the teaching; this absence is not well received by the students. However, teachers argue that the large numbers of the mixed-ability classes make individualization impossible; they relegate their didactic efforts to ability groups. Teaching in homogeneous ability groups differs from teaching in a heterogeneous classroom in various ways.
Teaching in the lower-ability group is usually focused on practicing and repeating the material. This approach was evident across all cases. “I have a set of examples prepared and we just count, one after the other, so that they learn as much as possible, I don’t have any higher ambitions for them, there is no time for that, I am glad that we can do what we have to do, that they understand the basics,” said Zita (teacher). The fact that teachers choose only routine exercises without stimulating moments for this group of students was confirmed by other teachers in the interview in all observed settings. Sidney (teacher), for example, claimed that “the worse ones are happy to finish the basics, and I am too. I am glad that we can manage to discuss what we have in our weekly plan. So, I do not know how it is in other subjects, in mathematics. You’ll have to ask a colleague, but I wouldn’t get my hopes up.” These statements confirm that the fixation of learning for this group of students takes the form of repetitive exercises with which teachers fill the whole teaching unit. They do not use activating methods with this group of students. They argue that they must ensure that the core curriculum is achieved for everyone, and that this takes longer for the lower-ability group, so there is no time for other activities. Respondents chose a more attractive form of teaching for the higher-ability group, who, according to the teachers, can understand the material more quickly. Therefore, teachers can use differentiated lessons to offer the higher-ability students some extra enrichment.
By enrichment, teachers mean more interesting and fun activities for which there is not time in the mixed-ability heterogeneous lessons. Across all classrooms, teachers described similar enrichment practices. Examples of such activities are “puzzles, crossword puzzles,” as Lea (teacher) stated. The observation data also indicated the use of various puzzles, mathematical puns. From the Czech language, teachers select various “brainteasers”—as Sarah (teacher) described them. As a rule, teachers select these activities as ad hoc and not necessarily related to the actual curriculum. The second option is more cognitively demanding activities that are related to the material being taught. Teachers usually choose differentiated assignments according to difficulty. Teachers assign easier tasks to the lower-ability group; the higher-ability students are given more cognitively challenging tasks. An example of a differentiated assignment was given by Sidney (teacher): For the weaker group, I will give an exercise to practice the verbal categories of verbs and for the other group, we talked about verbs, and in what tenses they usually occur in artistic texts, professional texts, manuals, and so on, and we got thematically somewhere else. Like that kind of thing, or if we talk about proverbs and sayings, here in the worse group I’ll be glad if they know at least something and in the better group, one can discuss maybe fifty of those sayings and proverbs, one can discuss books, because in the worse group there are not many people who read, but in the better group there are readers, so there’s a chance to discuss more, to talk about culture, ethics, which is not normal stuff, it’s a debate about literature. But if the other group does not read, there’s nothing to discuss.
Teachers do not require all students to master the same sufficiently challenging content. Rather than aiming for higher standards with appropriate support, teachers in the lower-ability group settle for knowledge of the core curriculum; in the higher-ability group, teachers opt for enrichment beyond the usual scope of the curriculum. Teachers present these students with additional activities with higher demands than those of their classmates. In Sidney’s example, the activities were at a higher level of abstraction, in which the teacher tried to bring in proverbs and sayings as well as ethical and moral issues. There is an extension of the curriculum to topics other than those included in the current curriculum.
Teachers have different requirements for the difficulty of teaching in each group, which is also related to different expectations of the results achieved. While students in the higher-ability group are offered stimulating and deepening curriculum activities by teachers, students in the lower-ability group are not. Teachers segregate students according to ability, which leads them to label students haphazardly. They then choose tasks according to the label and believe that lower-ability students cannot do the more difficult tasks. As a result, the teachers do not focus on developing existing skills. They set a mental limit, a ceiling, which they stay below with simpler activities and routine practice. This may not be perceived as problematic. However, teachers set the ceiling for students themselves, according to the label they assign to the group. They rarely go beyond it, although more challenging tasks could be managed by lower-ability students with appropriate support and help. Instead of lowering the demands on weaker students, the teachers could easily offer more assistance, then all students could meet the same requirements.
Teachers perceive the higher-ability group of students as not needing to practice mechanically or to the same extent as the lower-ability group, so they are presented with tasks at a higher level of cognitive processing. This group of students is perceived by teachers as having an open ceiling, and this perception is reflected in the choice of tasks.
The form of differentiated instruction is tailored to the ascribed label of the group rather than the actual ability level of the students in the group. If teachers maintain their established practices, group instruction can become fossilized. Flexibility is the hallmark of differentiated instruction. Even more differently, if teachers continually routinely practice with a lower-ability group, while permanently developing a higher-ability group, teaching may become unresponsive to actual student ability. I assume that student ability may be variable. This assumption proved valid in the present research. In the following section, I present situations that illustrate that the fixed form of instruction in ability-based groups does not always respond to the actual needs of individual students.
Limits of Teaching in Ability-Based Groups: Mismatches in the Individual Needs of Students
Before looking at situations in which the form of teaching is not in line with the needs of the students, I think it is important to mention that both groups of students receive more support and help from teachers when carrying out learning tasks in groups than in a heterogeneous classroom. This pattern was consistent across all participating classrooms. This message is supported by the teachers, the students, and the observation data. For example, Tom (student), who is in the lower-ability group, considers the supportive behavior of the teachers as one of the greatest benefits of differentiated instruction: When I thought it was a sentence analysis in Czech and it went wrong and now, I do not know what it was, the teacher explained what I did wrong and why I did it wrong. That is what is just great about the half-and-half lessons, that she explains the mistakes quietly on the blackboard, so we don’t make them again.
The quotation illustrates that the lower-ability students are not afraid to make mistakes only within their group because they know that their teachers take the time necessary to analyze the error and correct it. Thus, making a mistake is not a stigma for the students. If students do not understand what they are learning, they can speak out. However, this requires a safe environment in which teachers do not criticize mistakes; on the contrary, teachers defend and welcome mistakes and instill this attitude in the students themselves. The observation data contained several accounts of situations in which teachers explicitly encouraged students to take risks if they were unsure of the correctness of an answer. For example, in Czech language lessons, in a differentiated group, Eve (teacher) encouraged students verbally when repeating grammar rules: “Don’t be afraid to raise your hand, it doesn’t matter if you get it wrong. I will help you, advise you, correct you. Take advantage of the fact that only half of you is here and there is time for it.”
In the same way that students from the lower-ability groups appreciate teacher support and help when they do not understand the material, students from the higher-ability groups also appreciate the care in this respect: In those half-day classes, “it is just nice that the teacher can explain anything to us when we do not understand,” said Tim (student) in an interview. Matthew (student) stated: “Now we were getting grades in math and geometry, so I got a B and the teacher offered to explain it to me in the group and then call me to the board and I could correct it. And she would cross off the low grade. So, I took advantage of that and next Tuesday I will be called up.”
The demonstration illustrates that students are allowed to correct a bad grade, that teachers first explain the material again and then offer students the opportunity to volunteer for correction. Students value this opportunity and take advantage of it.
However, deeper analyses have shown that the level of teacher attention and overall help, including the way it is provided, may not always match the actual needs of the students in the groups. Inappropriate supportive behaviors were identified by both groups. The group of lower-ability students considered support to be excessive and bothersome in some situations; the group of higher-ability students considered the support to be insufficient in some situations.
Students from the lower-ability group perceive the level of help as excessive and therefore undesirable, generally in situations in which they have been assigned independent work, either for practicing or testing. Similar student responses emerged across different settings. Observational data illustrate that teachers often move between individual students and monitor their work during independent work. The moment teachers perceive an incorrect procedure, they immediately draw the student’s attention to it. This is to protect the students from receiving worse grades. That this protective approach can be received unpleasantly by students is illustrated by the testimony from Elizabeth (student): Sometimes it disturbs us as he keeps going around and asking, just asking if we understand, everyone nods and then he goes around the desks and gives advice anyway. Now in Czech language, as we were doing the worksheet, the teacher came to me and immediately said I should look at the sentence again, that I was missing something, only I knew it and I wanted to finish it, but only after I finished the next exercise.
Elizabeth described what teacher help looks like when teachers give them written work. With the support of the observation data, it can be added that this is the standard behavior of teachers when students are working independently. Elizabeth noted that teacher help can sometimes be undesirable; in her case, it was unwanted. She was aware that something was missing in her sentence and wanted to correct it herself later.
Teachers intervene in this way regularly. However, although these interventions are made in good faith by teachers, they are not always welcomed by students, especially when they know about their potential mistakes and plan to go back and revise them. Over-protectiveness against potential failure and premature lowering of standards is thus not well received by students. Moreover, it appears that students do not have the opportunity to take responsibility for their learning. By becoming too involved in the students’ learning process, teachers deprive students of the opportunity to reflect on what they have learned and correct any mistakes.
Excessive teacher concern for students was an observation echoed by other students. Linda (student), for example, admitted in one of the informal interviews that her Czech teacher “sometimes treats us like first graders, when we’re the, like, inferior group, so we need like ten times to explain everything, and like sometimes we do, but sometimes we don’t, we don’t need to.” Paul (student), who was standing next to Linda, added: “He keeps asking us if we understand.” From these statements from Linda and Paul, it appears that the teacher is making too much effort to ensure that the students understand the material sufficiently. Linda justified the teacher’s behavior by the composition of the students in the group. She referred to her own group using the adjective “inferior,” which, according to them, needs care, but the way the teacher provides it makes the students believe that they are the inferior group. And that bothered Linda.
The students in the lower-ability group do not mind the more intensive support from the teachers. They admit that sometimes they welcome the help, but they are bothered that there is a projected group label behind the support. By being over-protective and constantly requiring reassurance that the students understand the curriculum and do not need help, teachers are implicitly telling students that they are in a low-ability group that needs such interventions. The lower teacher expectations for this group’s ability and the corresponding teacher behavior reinforce the student identity as the low-ability students. This again confirms that the design of teaching is based on the perceptions of the group and on the expectations of student ability rather than on actual ability.
Teachers approach students from the higher-ability group in a similar but opposite way. This pattern was observed consistently across all cases. They have higher expectations of these students; this corresponds to the choice of activities, the choice of teaching strategies, and the level and type of support in the learning process. Teachers treat this group as “infallible” and not in need of help. They expect teaching to be smooth. This is evidenced by this statement from Zita (teacher) “So the demands are automatically higher for the better group. There I expect independence, readiness.” But the students complained in interviews that the teachers’ attention was sometimes insufficient, sometimes even absent. Dita (student), for example, said, “Like sometimes the teacher is so fast, we do so much in those halves compared to the other group. Sometimes we just go exercise after exercise, I feel like a robot that is exploding, and the teacher never waits.” Other students also reported the fast pace of the class and the volume of exercises. Ellen (student) echoed Dita’s statement, stating, “Like sometimes I really can’t keep up at all, we just described a few pages, my hand and pen were completely sweaty. I was totally like; the worse ones are like cool.”
On the one hand, students appreciate that teachers offer them space to explain what they are learning when there is time to explain it in differentiated teaching. On the other hand, they complain about the high work pace, which makes them complete an excessive amount of exercise. If the students do not keep up with the work pace, the teacher, they say, does not slow down and thus does not respond to their needs. The work pace set is perhaps even more intense when compared to the number of exercises completed by the other group of students. In case of discomfort felt by the group, they turn their attention to the less efficient students. The students also seem to want to slow down a little at times.
Not only do the students feel a desire for a slower pace, but in interviews they expressed that they sometimes feel literally “terribly pressured,” Ellen (student) admitted. When asked in which situations they feel pressured, students gave different answers. For example, Ellen and Dana (student) said: When we calculate a difficult example in math, the teacher is like, “Chop, chop, you should have it done by now,” while we are all doing the math. Or when we were doing the five-minute decimal test, the teacher was like, it is an easy test, and we all must get an A, when we have been studying it like recently. I just feel like if we are the better group, it is like we always must know a thousand per cent of everything.
Students reflect on the fast-paced teaching, with which they are not always comfortable. In addition to the pressure to learn at a good pace, they also comment on the pressure the teacher puts on them to perform. According to the students, the teacher takes the 5-min lesson as an easy revision test in which this group should be successful.
Again, therefore, teachers choose to teach in groups according to their label and according to their expectations about student ability. Students in the higher-ability group carry the label of “infallible” students who do not need as much attention and help as their counterparts. It is as if these students are not entitled to make mistakes and do not need help and support. Teacher expectations and teaching style do not allow students to shake off the label.
Ability grouping provides teachers with a space to practise learning that students have not sufficiently mastered. This benefit is valued by students in both groups and their teachers. However, teachers sometimes waver in the level and type of support students need. By planning lessons based on expectations about group ability rather than actual needs, teacher support can feel inadequate. Students in the lower-ability group may find teacher help superfluous. Over-protection from failure and constant checking reinforce their group identity. These practices fix the identity of lower-ability students. Additionally, students in the higher-ability group sometimes feel teacher attention is lacking. The pressure to perform and high workload can stress students, rather than encouraging them to excel.
Teachers select activities and resources to meet objectives according to expectations about student ability in groups. However, the demand for ability is permanent from the teachers’ perspective; these fixed didactic practices result in the emergence of conserved groups with conserved ability. Teaching is not responsive to student ability; it does not consider the possibility that student needs may change over time. While group settings are flexible in some classes, student needs may change more frequently.
Discussion
The aim of the study was to investigate how teaching takes place in a hybrid form of ability grouping, in which schools combine teaching in a heterogeneous classroom with teaching in ability-based groups. The study also investigated how the form of teaching addresses the individual needs of all students.
The results revealed a critical paradox at the heart of hybrid ability grouping: while this organizational model is designed to offer flexibility and tailored instruction, it may inadvertently reinforce pedagogical rigidity and fixed expectations. Teachers had different expectations of student ability in each group, which fundamentally shaped instructional design. In higher-ability groups, teaching emphasized cognitively demanding tasks and curricular enrichment; in lower-ability groups, instruction focused on mastery of core knowledge through routine practice. While such differentiation appears logical on the surface, the data revealed that these instructional patterns remained largely static over time, regardless of changes in individual student progress or needs.
This finding extends beyond confirming existing concerns about ability grouping (e.g. Francis et al., 2019; Ireson et al., 2005; Mazenod et al., 2019; Wright & Forrester, 2025) by revealing a structural mechanism through which hybrid models may intensify rather than mitigate the inequitable effects of tracking. I argue that the resulting instructional design is deeply rooted in teachers’ implicit mindsets about ability (Dweck, 2006). A fixed mindset—the belief that student ability is stable and predetermined—becomes operationalized through ability grouping structures, creating what I term “pedagogical path dependency.” Once students are sorted into groups and instructional routines are established, teachers find it cognitively easier to maintain these patterns than to continuously reassess and adapt. This represents a new theoretical contribution: hybrid grouping does not simply reflect teacher beliefs; it actively reinforces and institutionalizes them through organizational routines.
This mechanism helps explain why ability grouping persists despite extensive evidence of its inequitable outcomes. The organizational structure provides teachers with a seemingly rational justification for differentiated expectations, making it harder to recognize or challenge the fixed mindset underlying their practice. As Barbier et al. (2022) and Jaffe (2020) have shown, teacher mindsets fundamentally shape expectations and instructional approaches. This study demonstrates that hybrid grouping systems may create an institutional feedback loop in which organizational structures and individual beliefs mutually reinforce one another, deepening educational stratification over time.
The consistency of these patterns across all observed cases strengthens this interpretation. Despite variations in teacher experience, school context, and classroom composition, the same mechanisms emerged: teachers maintained static instructional routines, relied on group-level categorizations rather than individual assessments, and justified their practices through the organizational structure of ability grouping. This cross-case uniformity suggests that the observed patterns are not unique to teachers or settings but are instead structurally embedded in the hybrid grouping model itself. The lack of variation indicates that pedagogical path dependency operates as a systemic phenomenon rather than an artifact of individual teacher beliefs or contextual factors. This finding has important theoretical implications: it suggests that hybrid grouping creates institutional conditions that constrain teacher agency and reinforce fixed practices, regardless of individual teachers’ intentions or professional backgrounds.
Paradoxically, the very mechanism intended to facilitate differentiation—grouping students by ability—may reduce teachers’ attention to individual differences. The data showed that teachers adapted instruction to the perceived characteristics of the group, creating what Boaler et al. (2000) termed a “one size fits all” approach within each ability band. This finding aligns with Burris and Garrity's (2008) observation that teachers differentiate instruction more in heterogeneous settings, where visible diversity compels them to adapt.
I propose that ability grouping creates an illusion of homogeneity that obscures within-group variation. When students are grouped into relatively homogeneous clusters, teachers cognitively construct an “imaginary average student” for each group, streamlining instructional planning but overlooking individual trajectories. This phenomenon has been documented across multiple contexts: teachers tend to treat ability groups as uniform entities despite significant within-group diversity (Gamoran, 1992; Hallam & Parsons, 2013). Research shows that once students are categorized, teachers often fail to recognize individual progress or changing needs, leading to what Weinstein (2002) termed “expectation-driven instruction” rather than evidence-based responsiveness. This cognitive shortcut is reinforced by time constraints, curricular pressures, and the absence of systematic formative assessment practices that would reveal shifting student needs. As Tan and Dimmock (2022) emphasized, even ability-grouped classes are never truly homogeneous; student abilities and progress are dynamic and require continuous monitoring.
The theoretical implication is significant: ability grouping may function as a cognitive heuristic that simplifies teachers’ complex decision-making but at the cost of instructional responsiveness. This challenges Tomlinson (2014) framework of differentiated instruction, which emphasizes proactive adaptation based on readiness, interest, and learning profile. The data suggest that organizational differentiation (grouping) can substitute for rather than support pedagogical differentiation (adaptive teaching), creating a false sense of having “addressed” diversity without genuinely responding to individual learners.
Hand in hand with teachers’ fixed mindsets, students themselves adopted fixed self-perceptions aligned with their group placement, exemplifying Merton's (1948) concept of the self-fulfilling prophecy. This study reveals that hybrid grouping systems may accelerate this process through what I term “identity amplification.” Unlike traditional tracking, hybrid models expose students to both heterogeneous and homogeneous settings within the same school day, making ability-based identities more salient and visible. Students in lower-ability groups directly compare their instructional experiences (routine practice, slower pace) with those of higher-ability peers (enrichment, autonomy), reinforcing perceptions of fixed differences. This finding aligns with extensive research documenting how ability grouping shapes student self-concept and academic identity (Ireson & Hallam, 2001; Oakes, 2005). Studies have consistently shown that students internalize group placements as indicators of fixed ability, with placement in lower groups associated with diminished self-efficacy, reduced motivation, and disengagement (Rubie-Davies et al., 2006). As Francis et al. (2017) noted, this accelerates students’ self-perceptions as “better” or “worse,” influencing their engagement, effort, and academic trajectory—creating a mutually reinforcing cycle in which organizational structures, teacher beliefs, and student identities become tightly interwoven.
A particularly striking finding was that the combination of heterogeneous and homogeneous settings negatively affected instruction in heterogeneous classrooms. Teachers relegated differentiation and individualized practices to ability-grouped sessions, while whole-class instruction became predominantly frontal and uniform. Teachers justified this approach by citing large class sizes and the difficulty of addressing diverse needs without grouping structures.
This pattern suggests that hybrid grouping may inadvertently deskill teachers in heterogeneous pedagogy. By outsourcing differentiation to ability groups, teachers lose opportunities to develop and refine adaptive teaching strategies applicable to diverse classrooms. This finding has significant implications for ongoing debates about detracking and inclusion. If teachers become dependent on ability grouping to manage diversity, efforts to promote more inclusive, heterogeneous instruction may face substantial resistance—not because such instruction is impossible, but because teachers lack confidence, skills, and institutional support to implement it effectively (Francis et al., 2019; George, 2005).
Moreover, this finding challenges the assumption that hybrid models represent a “middle ground” between tracking and full heterogeneity. Instead, the data suggest that hybrid grouping may combine the worst of both worlds: it retains the stratifying effects of ability grouping while simultaneously undermining the development of inclusive pedagogies. Differentiated instruction becomes an occasional, context-specific practice rather than a transferable, deeply embedded professional competency. These findings raise questions about the broader relevance of hybrid grouping models beyond the Czech context.
While this study is situated within the Czech educational context, the mechanisms and outcomes observed resonate strongly with international trends, suggesting broader relevance beyond national boundaries. The Czech Republic’s highly selective education system, characterized by early tracking and pronounced educational inequalities (OECD, 2023), shares structural similarities with countries such as Germany, Austria, and parts of Belgium, where streaming and tracking remain institutionally embedded (Van de Werfhorst, 2019). The emergence of hybrid grouping models in Czech lower elementary schools can be understood as part of a broader pattern in selective systems, where schools seek to maintain differentiation while responding to policy pressures toward inclusion and equity.
However, the Czech experience also reveals important divergences from international patterns. In comprehensive education systems—such as Finland, Norway, and Scotland—ability grouping at the elementary level is far less common, and policy frameworks actively discourage it in favor of inclusive, mixed-ability teaching (Dupriez et al., 2008). The findings suggest that the Czech Republic is moving in the opposite direction, expanding ability grouping as a pragmatic response to diversity. This trajectory aligns more closely with practices observed in the United States and England, where setting and tracking remain widespread despite decades of critique (Francis et al., 2020; Gamoran, 2010).
Importantly, the core mechanisms identified in this study—pedagogical path dependency, the illusion of homogeneity, and identity amplification—appear to operate across national contexts. Research from the United Kingdom (Francis et al., 2017; Mazenod et al., 2019), the United States (Boaler et al., 2000; Burris & Garrity, 2008), and Singapore (Tan & Dimmock, 2022) has documented strikingly similar patterns: teachers’ fixed mindsets, static instructional routines within ability groups, and the acceleration of self-fulfilling prophecies. This cross-national consistency suggests that these mechanisms reflect deeper psychological and organizational dynamics inherent to ability grouping rather than artifacts of any national system. This interpretation is further reinforced by the consistency observed within the present study: across all participating classrooms, the same patterns emerged with remarkable uniformity, despite differences in teacher experience and school characteristics.
The specific form of hybrid grouping observed in Czech schools, however, may represent a novel organizational configuration. Unlike traditional tracking or setting, hybrid grouping exposes students to both homogeneous and heterogeneous instructional contexts within the same school day, intensifying the visibility of ability-based identities as students directly compare their experiences across settings. While similar practices exist informally elsewhere, the formalization of hybrid models in Czech elementary schools may signal an emerging international trend, particularly in systems grappling with tensions between selection and inclusion. The findings thus have implications for international debates on detracking: in systems where ability grouping is deeply institutionalized, reform efforts may require not only policy change but also sustained investment in teacher professional development to build capacity for heterogeneous pedagogy.
An important question arising from these findings is whether smaller heterogeneous groups might enable differentiation without ability grouping’s stratifying effects. In the observed classrooms, students experienced small-group instruction exclusively within ability-grouped settings; heterogeneous lessons remained whole-class and predominantly frontal. Teachers cited large class sizes as barriers to differentiation, yet the data show that students’ experiences in ability-based groups were constrained by group placement: lower-ability students encountered routine practice with limited challenge, while higher-ability students received enrichment regardless of individual needs. Group-level categorization thus capped instructional experiences rather than responding to individual heterogeneity.
The role of class size as a barrier to differentiated instruction is well-documented in educational research, though its effects are complex and context dependent. Large class sizes consistently correlate with reduced opportunities for individualized attention, limited formative assessment, and increased reliance on whole-class instruction (Blatchford et al., 2011; Finn et al., 2003). However, research also demonstrates that class size alone does not determine instructional quality; teacher pedagogical skills, beliefs about differentiation, and systemic support structures mediate its effects (Hattie, 2005; Tomlinson et al., 2003). Studies examining class size reduction initiatives reveal that smaller classes enable more differentiated instruction only when teachers possess the necessary competencies and when reduction is accompanied by professional development (Konstantopoulos & Chung, 2009).
The present findings suggest that class size functions as a confounding factor in teachers’ decisions to implement ability grouping. Teachers justified their reliance on ability-based groups by citing the impossibility of individualization in large heterogeneous classes, yet they demonstrated capacity for differentiation when working with smaller ability-grouped settings. This raises a critical question: Is the barrier truly class size, or is it the combination of large class size and heterogeneity that teachers find unmanageable? The data suggest the latter—teachers did not differentiate effectively even in smaller ability groups when they treated those groups as homogeneous units. This reinforces the earlier argument that ability grouping functions as a simplifying mechanism that obscures rather than resolves the pedagogical challenge of responding to individual needs in diverse classrooms.
Research from comprehensive systems demonstrates that smaller heterogeneous classes with co-teaching support can facilitate differentiation (Dupriez et al., 2008). However, this requires investment in reduced class sizes and professional development. Future research should examine conditions under which smaller heterogeneous groupings sustain differentiated instruction without ability-based structures.
Implications for Policy, Practice and Teacher Professional Development
These findings carry significant implications for educational policy and practice, particularly in contexts like the Czech Republic, where selective systems and emerging forms of ability grouping are expanding (OECD, 2023; Straková, 2021).
At the policy level, the proliferation of hybrid ability grouping in lower elementary schools requires critical examination. While such models may appear to balance differentiation and inclusion, this study demonstrates that they risk institutionalizing fixed mindsets and pedagogical rigidity. Policymakers should limit ability grouping to short-term, flexible interventions rather than semi-permanent structures, ensuring that grouping remains fluid and based on specific learning needs rather than generalized ability judgments. Schools should document and evaluate the impact of grouping practices on student learning, participation, and self-concept, with particular attention to equity outcomes. Promoting whole-school approaches to differentiation within heterogeneous classrooms—supported by smaller class sizes, additional staffing, and collaborative planning time—would help mitigate the stratifying effects observed in this study.
At the practice level, teachers require explicit support to recognize and challenge fixed mindsets. This involves embedding growth mindset principles into classroom discourse and assessment, emphasizing effort and progress while avoiding ability labels. Formative assessment should track individual progress and inform instructional adjustments rather than justify group placement. Teachers must also develop differentiation strategies applicable in heterogeneous settings, including flexible grouping, tiered tasks, and scaffolding (Tomlinson, 2014).
Finally, sustained professional development focused on differentiated instruction in diverse classrooms is essential. Both preservice and in-service training should address implicit biases, mindset theory, and the risks of ability grouping (Walton et al., 2022; Whitley et al., 2019). Collaborative inquiry models—such as lesson study and professional learning communities—enable teachers to observe and refine differentiated instruction in heterogeneous settings. Mentoring and coaching can support shifts from group-level to individual-level responsiveness. Without such investment, teachers may continue relying on ability grouping as a cognitive shortcut, perpetuating fixed expectations and pedagogical rigidity.
Footnotes
Funding
The author received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.