Abstract
Children with developmental language disorders (DLD) usually experience delays in vocabulary learning and deficits in cumulative vocabulary knowledge. Speech-language pathologists (SLPs) typically assess children’s and adolescents’ vocabulary to develop intervention strategies. Speech-language pathologists should assess both breadth and depth of vocabulary. Breadth refers to the number of words known and depth refers to the amount of knowledge about each word (McGregor et al., 2013). Word knowledge is not binary (known or unknown), but rather exists along a continuum from never having heard the word or having heard it but having no idea of what it means to knowing multiple meanings of the word or multiple contexts in which it could be used. A variety of standardized and informal vocabulary tasks are necessary to assess vocabulary breadth and depth.
Comprehensive language tests such as the Clinical Evaluation of Language Fundmentals-5 (CELF-5; Semel et al., 2013); the Test of Integrated Language and Literacy (TILLS; Nelson et al., 2016); the Oral and Written Language Scales-II (OWLS, Carrow-Woolfolk, 2011); and the Comprehensive Assessment of Spoken Language (CASL-2; Carrow-Woolfolk, 2017) all have subtests or items specifically designed to assess receptive and expressive vocabulary knowledge and use. Several tests are vocabulary specific, for example, The Peabody Picture Vocabulary Test-5 (PPVT-5; Dunn, 2018) and the Receptive One-Word Picture Vocabulary Test, Fourth Edition (ROWPVT-4; Martin & Brownell, 2011b) are each measures of receptive vocabulary skills; the Expressive Vocabulary Test-2 (EVT-2, Williams, 2018) and the Expressive One-Word Picture Vocabulary Test-4 (EOWPVT-4; Martin & Brownell, 2011a) are each measures of expressive vocabulary skills. In the most common receptive format, examiners provide a word or phrase and the child points to the matching picture from a choice of three or four. In the most common expressive formats, children label a picture or provide a synonym. Other expressive tasks include providing definitions; explaining word relationships; and stating categories, attributes, or functions.
There are several limitations with standardized vocabulary tests:
They often do not distinguish between types of poor performers: those with underlying language impairment versus those with home language learning experiences that differ from the normative sample (Horton-Ikard & Ellis Weismer, 2007).
Because several standardized vocabulary tests require that a child only point or label, they provide superficial word knowledge.
Because standardized tests cannot be repeatedly administered within a short time frame, they cannot be used for progress monitoring.
Informal assessment techniques may include parent/caregiver or teacher report, language sample analysis, dynamic assessment (DA), curricular-based measures, and clinician-created tasks. Parent/caregiver report measures are commonly used for young children for whom standardized language tests may not be appropriate. Parent report measures of young children’s language have high reliability and validity and can be used for monitoring progress (Gilkerson et al., 2017). Although empirical support exists for parent report, the accuracy of teacher report for identifying language weaknesses in children is less clear (Gregory & Oetting, 2018).
Speech-language pathologists do not regularly employ language sample analysis; yet because it can be conducted repeatedly, it is useful for monitoring progress (Miller et al., 2011). Number of different words in a language sample is indicative of vocabulary diversity and helps to identify children with language impairments (Watkins et al., 1995). Language samples may also be coded for semantic errors and generic word use (Miller et al., 2011). When standard protocols are used, such as the narrative, expository, and persuasive protocols available on the Systematic Analysis of Language Transcripts (SALT) website (www.saltsoftware.com), measures can be compared with normative databases, which is beneficial for identifying vocabulary deficits as well as strengths and weaknesses.
Dynamic assessment is an informal procedure used to measure students’ learnability or modifiability. Dynamic assessment is especially helpful in appropriately diagnosing children from culturally/linguistically diverse backgrounds (Camilleri & Botting, 2013; Petersen et al., 2020). The purpose of DA is to obtain information regarding a child’s approach to learning, a child’s error patterns, the level at which a breakdown occurs, and the child’s ability to self-correct. Petersen et al. (2020) employed a DA of vocabulary learning with elementary school–age English/Spanish bilingual children. Children listened to short narratives that had a single nonsense word (a verb) embedded two times within the story. The nonsense verb was written in regular past tense in one section of the story (e.g., “punuped”) and written in the infinitive form in another section of the story (e.g., to punup). An examiner taught the children strategies for inferring the meanings of the nonsense words. The DA procedures yielded better sensitivity and specificity for identifying children with and without vocabulary deficits than the standardized receptive and expressive vocabulary assessments.
In their article, Steele and Gibbons (2023) recommend four approaches to vocabulary assessment:
Assess a child’s ability to incidentally learn words from context through fast mapping tasks such as those demonstrated in videos on the Leadersproject website (https://www.leadersproject.org/category/glossary/fast-mapping/) or found in the Diagnostic Evaluation of Language Variation (Seymour et al., 2005). Assessing a child’s fast mapping skill is important because it measures the underlying word learning process, rather than word knowledge, which is influenced by a child’s exposure to the words on the standardized tests and can be culturally biased.
Assess a child’s morphological awareness, as many word meanings can be inferred from morphological structure. Larsen and Nippold (2007) and Ram et al. (2013) have published DA tasks for morphological analysis, a cognitive skill of determining word meaning by using knowledge of affixes and root words.
Use sorting or labeling tasks to assess a child’s understanding of category membership, part–whole relationships, and thematic relationships (Brackenbury & Pye, 2005).
Assess depth of word knowledge, such as (a) syntactic knowledge, for example, part of speech, grammatical use in sentence; (b) collocational knowledge, for example, blustery occurring with day or serious occurring with offense; (c) semantic and topic associations, for example, monarch, royal, and ruler are related; and (d) semantic relations and attributes, such as producing synonyms and antonyms, and completing analogies (McKeown et al., 2017). The Vocabulary Knowledge Scale provides a system for evaluating students’ depth of vocabulary knowledge and tracking depth of knowledge over time. Students are asked to evaluate their own word knowledge. There are several variations of the Vocabulary Knowledge Scale (e.g., Dale, 1965; Paribakht & Wesche, 1997). Below is a synthesis of several of them:
Never having seen the word before: I don’t remember having seen this word before. Knowing there is such a word, but not knowing what it means: I have seen this word before, but I don’t know what it means. Knowing something about the word and can relate it to a situation: I have seen this word before, and I think it means ______. Knowing the use of the word in a specific situation: I know this word means ________. Knowing the word well (knowing multiple meanings or multiple contexts in which it can be used) and remembering it: I can use this word in a sentence: _________.
Student self-assessments can provide reasonably accurate measures of vocabulary knowledge, particularly when students say that they do not know a word, but they may be unreliable because they not only depend on depth of word knowledge but also on a degree of the students’ metalinguistic awareness.
Steele and Gibbons (2023) surveyed 400 school-based SLPs regarding the assessments they used for identifying vocabulary deficits and monitoring progress. Speech-language pathologists regularly used standardized tests most frequently for identifying vocabulary deficits, and they indicated a preference for comprehensive language tests over vocabulary-specific tests. Such tests do not assess all aspects of vocabulary knowledge. The SLPs made some use of language samples, but they seldom used standardized protocols (such as the SALT protocols) that would be needed to identify if students had vocabulary deficits. They rarely made use of DA vocabulary measures to identify vocabulary deficits. They also reported making some use of observation and parent, teacher, and student interviews to identify vocabulary deficits. Although teacher and parent reports have some research base for identifying student vocabulary deficits, there is no evidence that student observation and student interview yield valid determination of vocabulary deficits. For progress monitoring of vocabulary growth, SLPs reported most frequently using clinician-created or curriculum-based tasks. In these tasks, they typically asked students to give oral definitions or synonyms. Ideally, SLPs should consider a wider variety of measures to adequately assess students’ vocabulary knowledge.