Abstract
Knowledge in urban planning is typically categorized as either ‘professional’ or ‘local’, based primarily on the identity of the knower. We argue that this binary framework has become outdated due to shifts in planning and its broader societal context, and now hinders our ability to understand the role of knowledge and power–knowledge dynamics in planning processes. In its place, we propose an updated and expanded typology of planning knowledges, and a method for identifying them through discourse analysis. We also show how knowledge types, which are now wielded by diverse actors in varied discourse arenas, can no longer be associated exclusively with specific knowers, and often merge into novel hybrids – and consider how these changes impact power–knowledge dynamics. We aim to contribute to the development of a more nuanced and precise epistemology in planning, and hope our proposed framework enriches the understanding of researchers and practitioners alike.
Introduction: Revisiting knowledge in urban planning
Planning has long been understood as a field ‘located precisely at the interface between knowledge and action’ (Friedmann and Hudson, 1974: 2). Exploring how knowledge gets translated into action has been ‘central to the concerns of planning theory’ (Campbell, 2012: 137), while plans themselves have been described as ‘a set of knowledge practices that physically construct a material reality’ (Tett and Wolfe, 1991: 199).
Since the 1960s, scholars have categorized the types of knowledge observed in planning processes in a binary way, as either ‘professional’ or ‘local’, with each type associated exclusively with specific actors. According to this approach, the former is held by professional planners, who acquire it through academic training and on-the-job experience, while the latter is gathered by lay people from everyday experience and familiarity with living environments (Corburn, 2003; Van Herzele, 2004). Much subsequent research has focused on power–knowledge relations (Foucault, 1980) between professional planners, whose ‘command of specialist knowledge’ (Rydin, 2007: 53) gives them an advantage in planning processes, and ordinary people, whose lay knowledge is generally undervalued (Fenster and Yacobi, 2005; Scott, 1998).
This article builds on the work of these scholars and others who described planning as a crucial field for citizen involvement and knowledge sharing (Rydin, 2007), and knowledge in planning as never objective (Healey, 1992b) and always connected to and shaped by power (Flyvbjerg, 1998; Forester, 1989). However, we challenge the binary distinction between professional and lay-local knowledges that is taken for granted in much of this literature, and argue that recent shifts in planning and society have led to the rise of new actors, discourse arenas and knowledge types that don’t fit neatly into this dichotomy – or, indeed, even conform to conventional definitions of knowledge.
These shifts include: (1) the emergence of a new neoliberal urban technocracy, which prioritizes specific types of growth-orientated knowledge in increasingly opaque ways (Raco et al., 2022; Savini and Raco, 2019); (2) the unprecedented popularization of planning knowledge and discourse via mass media coverage, social media, online platforms and data democratization (Giest et al., 2016; Margalit, 2022); and (3) the rise of alternative ways of knowing, ranging from populism to artificial intelligence (AI), which challenge the intersubjective nature of knowledge itself and impact its application in public life (Caprotti et al., 2024; Jha et al., 2021).
In this context, we contend that the widely cited professional–local knowledge dichotomy now hinders our understanding of contemporary knowledge and power–knowledge dynamics in planning, and that scholars should move beyond it and develop an updated and more nuanced epistemology. To make this concrete, we assemble a typology of contemporary knowledge types based on an extensive review of the literature on knowledge and planning. Instead of automatically associating specific knowledge types with specific actors, we use the analytical methods developed by Van Dijk (2003, 2012) and Fairclough (1989, 2003) to characterize them based on their discursive characteristics. Moreover, we show how planners, other professionals and laypeople now use varied knowledge types in a variety of discourse arenas, and discuss some of the questions this raises regarding power–knowledge relations between them.
Our work builds upon Rydin’s (2007: 54) observation that knowledge in planning is ‘inherently multiple, with multiple claims to representing reality and multiple ways of knowing’, and that it now has ‘a variety of sources and takes a variety of different forms’. Yet, as our typology shows, this multiplicity and variety have greatly increased in recent years. Neoliberal technocracy, for instance, has introduced new forms of expertise into planning, while knowledge popularization and widespread access to technical capabilities such as generative AI now allow non-professionals to wield various forms of professional and even technical knowledge, thus blurring the boundaries between ‘professional’ and ‘lay’ ways of knowing. We also elaborate on Davoudi’s (2015: 322) observation that in planning ‘the boundaries of knowledge are fluid and overlapping’, by showing how contemporary knowledge types can blend together and create novel, hybrid forms.
Our analysis adopts Rydin’s (2007: 58) suggestion that ‘the planning system should be conceptualized as a series of arenas in which a variety of knowledges engage with each other’. We show, however, that these knowledges are now deployed in an expanding variety of discourse arenas – both old and new, formal and informal. We do not argue that the well-established hierarchy between professional and lay arenas is completely obsolete, or that there is not some stability and fixity in them. Rather, we suggest that the current array of arenas constitute dynamic and ad-hoc ‘knowledge networks’ (Rydin, 2007: 52) in which a ‘system of meanings’ (Finlayson and Martin, 2006: 159) and relationships are constructed in new ways.
We conceptualize knowledge as the accumulated representations, assumptions and beliefs that people hold in their heads, which they use to interpret and express information (Fairclough, 1989; Rydin, 2007; Van Dijk, 2012). Epistemology is defined as the study of knowledge, what it means ‘to know’ and what knowledge is considered valid (Couper, 2020).
In the next section, we present some of the central scholarly debates over knowledge and power–knowledge relations in planning. We then briefly explore some of the trends observed in recent planning and social science research and their impacts on planning knowledge. Next, we present our updated typology of planning knowledges and their discursive characteristics, and conclude with a brief discussion of possible implications for power–knowledge dynamics in planning and with a call for planners and researchers to further develop the proposed framework.
Knowledge and power–knowledge relations in planning
The knowledge involved in planning processes, scholars have shown, is complex and multifaceted. It has proven notoriously difficult to define (Gunder, 2004), and goes by many names, including ‘evidence, information, expertise, data, facts, research, proof, statistics, interpretations, values, or intelligence’ (Campbell, 2012: 137). It is both descriptive and prescriptive, qualitative and quantitative, explicit and implicit, visual and textual, art and science (Friedmann, 1987; Gunder and Hillier, 2016; Innes, 1987; Schon, 1983; Soderstrom, 1996). It addresses physical built environments, as well as overlapping social and natural systems, and the interfaces between them (Sanchez, 2017).
Planning processes, according to the literature, draw upon professional expertise alongside lay knowledge (Carmon, 2013; Davoudi, 2009). Professional planners are ‘trained in conceiving, designing and implementing urban policies and plans’, which involve transformation of land uses, buildings and infrastructure (Moroni, 2020: 563). Their expertise is both distinct, that is, derived from specialized knowledge and know-how that is unique to planning, and inherently interdisciplinary, reflecting a multiplicity of actors and fields of expertise that are involved in planning (Carmon, 2013; Healey, 1992a). Local, ‘everyday’ or ‘ordinary’ knowledge, on the other hand, ‘does not owe its origin, testing, degree of verification, truth status, or currency to distinctive … professional techniques but rather to common sense, casual empiricism, or thoughtful speculation and analysis’ (Lindblom and Cohen, 1979: 12). It is based on lived experience and situated in specific geographical and cultural contexts (Geertz, 1983), reflects an intimate familiarity with living environments and is generally associated with lay individuals and communities (Corburn, 2003; Innes and Booher, 2010).
Modern professional planning knowledge, according to theorists, is not uniform and has taken on more and varied forms over time. The visionary planners of the early 20th century presented their reasoning as ‘scientific’ (Davoudi and Strange, 2009), while post-Second World War ‘rational’ planners professed to wield objective and universal knowledge (Friedmann, 1978). The theorists of the ‘communicative turn’ (Healey, 1992b) and the ‘interpretive tradition’ (Davoudi, 2012) followed Foucault (1980) in seeing knowledge and power–knowledge dynamics in planning as identity driven and politically inflected. The idea that planners’ knowledge can never truly be neutral or objective, but inevitably contains (conscious or unconscious) underlying assumptions and biases (Healey, 1992b), has become widely accepted.
Thus, while rational-scientific knowledge in many ways retains its dominant position (Davoudi, 2012), professional planning knowledge is now seen as encompassing multiple ways of knowing – including more systematized and positivist ‘hard’ knowledges and more interpretive ‘soft’ knowledges (Davoudi, 2012; Tamm Hallstrom, 2015). Healey (1992a: 17), for example, demonstrated how planners ‘operate across knowledge forms in their daily work’. These may include knowledge of the political dynamics that surround planning (Forester, 1989), tacit forms of understanding (Polanyi, 1966; Schon, 1983), knowledge of the personal and emotional aspects of planning (Baum, 2015; Innes, 1998), as well as practical judgement or ‘phronesis’ (Flyvbjerg, 2004).
Theorists have also pointed out a blind spot in the professional knowledge–action sequence: while the knowledge gathered by planners is descriptive, planning actions are prescriptive, and thus necessarily involve some form of normative judgement (Campbell, 2012). Others described knowledge and action in planning as ‘recursively interlinked’, rather than arrayed along ‘a linear, causal chain’ (Davoudi, 2015: 317).
Scholars have also consistently criticized professionalized planning for ignoring or excluding lay knowledge (Friedmann, 1973). Foucault (1980: 81) argued that popular forms of knowledge are often delegitimized or suppressed because they are produced outside of ‘established regimes of thought’, while Scott (1998) showed how professional knowledge can be imposed in place of local knowledge to facilitate greater centralization and control. Researchers have thus argued that local-lay knowledge is rarely ‘acknowledged as having any validity in the planning process’ (Sandercock, 1998: 63), and that planners perceive others’ ways of knowing as an epistemic threat to their status (Innes and Booher, 2010). Moreover, trained planners use inscrutable ‘exclusionary language’ to reinforce their power–knowledge advantage over non-planners (Weston and Weston, 2013), creating an ‘incredibly steep and energy sapping learning curve’ (Inch, 2015: 415) for laypeople who seek to learn their professional jargon (Fenster and Kulka, 2016).
To overcome this, scholars and practitioners have developed a range of tools and tactics to facilitate the expression of non-professional knowledge in planning processes (Kleinhans et al., 2015). In the process, planners have gone from being exclusive holders of knowledge to mediators and facilitators of ‘mutual understanding’ between various actors and knowledge types (Healey, 1992b: 240), while knowledge exchanges have become ‘a two-way transaction rather than one-way communication from expert to layman’ (Innes, 1987: 89).
Meanwhile, planning scholars from the Global South have increasingly challenged the universal application of knowledge produced in the Global North (Watson, 2009), arguing that ‘endogenous’ ways of knowing – or some combination of the two – are better suited to understanding and addressing urban realities in Southern contexts (Winkler, 2022).
While power–knowledge inequalities remain pervasive, theorists generally agree that contemporary planning processes must invariably contend with multiple knowledge types (Innes, 1987; Rydin, 2007). Yet, despite various attempts to create typologies of planning knowledges (see Alexander, 2005; Friedmann, 1987), much of planning theory and practice continues to relate to knowledge in a binary way, as either ‘professional’ or ‘local’ (Corburn, 2003; Van Herzele, 2004).
Planning in flux: New knowledge types, actors, arenas and epistemic challenges
We argue that in the years since the bulk of these debates took place, planning itself, along with the broader societal context in which it is embedded, has shifted in fundamental ways that necessitate a reassessment of the variety of knowledges involved in it. We focus on three major changes: the rise of new forms of technocratic expertise, the popularization of planning knowledge and the radical challenges to the very nature of knowledge itself posed by populism, AI and other epistemic trends.
First, professionalized planning has witnessed a pendulum shift in which highly systematized forms of growth-orientated knowledge and technical expertise have increasingly been ‘hierarchically imposed over other types of knowledges’ (Savini and Raco, 2019: 11). The expertise employed by this ‘new urban technocracy’ (Savini and Raco, 2019: 11) is composed of legal–contractual, technical, numerical and ‘hard’ knowledges (Tamm Hallstrom, 2015). In line with a broader trend observed in public policy discourse in the neoliberal era (Berman, 2022), economic reasoning has come to play a central role in planning processes (Layard, 2019). Planning rationales are now subordinated to quantitative housing targets and metrics (Raco et al., 2022), developer profitability calculations (Layard, 2019) and the logic of land valuations and public revenue maximization (Metzger and Zakhour, 2019). This has occurred in both the Global North and South, and in both liberal democracies and illiberal contexts – albeit to different extents (Savini and Raco, 2019).
In this new reality, planners have become ‘only one player among a broader spectrum of legitimate actors and stakeholders’ (Savini and Raco, 2019: 11), while their professional knowledge has been subordinated to that of starchitects, transnational design firms, ‘development engineers’, contract lawyers, accountants, appraisers, financiers, spreadsheet consultants, futurists and so on (Savini and Raco, 2019: 11). Likewise, the rise of ‘smart cities’ has centred the instrumental, positivist knowledges (Cook and Karvonen, 2024) wielded by actors such as chief innovation officers, data scientists, computer programmers, tech startups, philanthropists, user-interface designers and smart-city consultants (Kitchin et al., 2019). Tech corporations and entrepreneurs have taken on the role of planner and developer (Carr and Hesse, 2020), while plans are increasingly discussed in arenas such as hackathons, expos, corporate lobby groups, supra-national policy networks and advisory boards (Kitchin et al., 2019).
While ostensibly drawing on diverse disciplines, this trend has actually led to a standardization and homogenization of knowledge inputs, while suppressing ‘softer’ knowledges, including ‘less-necessary’ expertise and lay perspectives (Savini and Raco, 2019). Such narrowly technical, delivery-orientated knowledges place ‘less emphasis on the overarching meaning of the built environment or how a particular intervention will impact current and future residents’ (Cook and Karvonen, 2024: 374), while knowledge-generation and decision-making processes have been ‘black-boxed’ (Rydin et al., 2018) and depoliticized (Savini and Raco, 2019).
Second – and perhaps in response to the increasingly opaque nature of technocratic planning – a parallel process of knowledge popularization and democratization has occurred, with the realm of communicative planning expanding beyond regulatory and participatory frameworks. Media outlets, long seen as shaping public perceptions of planning issues (Forester, 1989), have greatly expanded their coverage of plans in recent years, with planners, developers and activists increasingly relying on mass media to reach large audiences (Fox and Margalit, 2024; Schweitzer and Stephenson, 2016). Social media networks and other online platforms constitute another informal arena for popularizing knowledge and engaging citizens (Kleinhans et al., 2015), including in non-democratic contexts (Gillespie and Nguyen, 2018). Likewise, open data portals, e-participation platforms and citizen-run websites enable knowledge sharing between citizens and planners, and among citizens (Giest et al., 2016; Rogers, 2016). Recent research describes processes of ‘knowledge co-production’ (Lall et al., 2023), in which multiple ways of knowing held by diverse networks of actors combine to create ‘mestizo knowledges’ (Cociña et al., 2023).
Thus, we argue, information on plans has increasingly become available to anyone with an internet connection, while new and diverse discourse arenas can, and often do, facilitate lively debates and the open exchange of information, thus enriching local knowledge and lay understandings of plans (Margalit, 2022). These arenas also have their limitations, such as the corporate media’s tendency to focus on marginal and symbolic aspects of plans, while reinforcing pre-existing power–knowledge hierarchies (Schweitzer and Stephenson, 2016). Moreover, they are still likely to foster epistemic injustice, with knowledge undervalued based on speakers’ marginalized identities (Fricker, 2007) – or overvalued (al-Gharbi, 2024), depending on the political–cultural context. It is also worth noting that greater availability of information, particularly online, does not necessarily lead to more widespread knowledge creation (Lynch, 2016).
Third, the very nature of knowledge in planning as a kind of intersubjective commons has been challenged from multiple directions. One such challenge comes from illiberal populist movements which, theorists argue, constitute distinct epistemic communities (Nawrocki, 2024) with their own sources of knowledge (Ylä-Anttila, 2018). These groups often exhibit extreme scepticism of and disdain for the epistemic authority of experts, including planners, who are perceived as unelected technocrats who serve elites (Fainstein and Novy, 2025; Sager, 2020). Populist movements often reject the shared knowledge of mainstream society and instead embrace ‘post-truth’, adopting ‘alternative facts’ and narratives (Bergmann, 2020). Research has shown how data democratization and social media, rather than combating these trends, have often helped spread false narratives (Flaherty et al., 2022).
In this context, scholars are also examining forms of not-knowing, such as denialism, that is, the motivated rejection of established empirical knowledge (Proctor and Schiebinger, 2008), agnotology, that is, the deliberate production of ignorance (Proctor and Schiebinger, 2008), and strategic ignorance, that is, the intentional avoidance of knowledge (McGoey, 2012). In some cases, non-knowledge can be seen as a greater source of power than knowledge itself (McGoey, 2012).
Another epistemic challenge is posed by the ‘algorithmic governance’ of cities (Smith, 2020), in which human knowledge is encoded into software (Kitchin, 2011) and often augmented by artificial intelligence (Peng et al., 2023), in order to automate urban processes (Cugurullo et al., 2024). Initial applications of this exist in the form of mobility and parking software (Nikitas et al., 2020), predictive models and generative AI design programmes (Peng et al., 2023), ‘smart’ neighbourhoods that continuously collect data from residents (Carr and Hesse, 2020) and ‘city brains’ (Cugurullo et al., 2024). While the implications of such still-evolving interventions are not yet well understood, their introduction of technical expertise from non-planning fields and non-human intelligence whose rationality is often opaque presents clear challenges to both professional and local knowledges.
While the processes described above are considered distinct and sometimes even contradictory, in planning, we argue, they are also interrelated. For instance, as knowledge becomes more democratized, experts may be tempted to retreat further behind the veil of technocracy and post-politics (Salter, 2016), and vice versa. Likewise, while emerging AI platforms are seen as an effective means of gathering local knowledge, they may also create further distance between planners and citizens by replacing direct human communication with impersonal, automated interactions (Cugurullo et al., 2024). Moreover, phenomena which are generally seen as mutually antagonistic – such as populism and technocracy (Salter, 2016) – have increasingly been observed to converge in unexpected ways, as recent scholarship on ‘technocratic populism’ (Bickerton and Accetti, 2021) suggests. Thus, technocratic knowledge is now popularized in ways that create ‘citizen-technocrats’ whose knowledge reflects professional understandings rather than local knowledge (Fox and Margalit, 2024).
Taken together, these developments herald fundamental shifts in the way that knowledge is produced, understood and communicated in contemporary planning. As Durning et al. (2010: 498) note, a political and social context in constant flux means that planners ‘are being constantly challenged as to what they know’. We argue that this new reality necessitates the development of a new epistemology in planning which broadens our conception of contemporary planning knowledge and its discursive expressions, and contributes to our understanding of the corresponding shifts in power–knowledge relations. Accordingly, in the next section we present a new typology of knowledge types in planning, based on an understanding of their discursive features rather than the identity of the knower.
An updated typology of knowledges in planning and their discursive representations
To compile our typology, we conducted a comprehensive review of the relevant theoretical and empirical academic research published in English since the 1960s that examined knowledge in the planning context, and identified a broad range of ways of knowing and expressing knowledge in planning (though by no means all). These were then organized into four distinct categories, each with their own set of common characteristics, which we detail below. These are loose categories and not meant to be seen as absolute. In cases where a knowledge type may be seen as belonging to more than one category, we have categorized it based on our interpretation of the literature.
Some types of knowledge mentioned in the literature have been consolidated or renamed for brevity and clarity. Some of the sources cited below represent the spiritual ‘mothers and fathers’ of these ideas, while others write about them from a distance or critique them. Most sources are from the planning literature, while research from the broader social sciences literature was drawn upon when this was seen as relevant to planning and helpful in further illuminating the ideas we discuss below.
To identify expressions of different knowledge types based on their discursive features, we draw upon Van Dijk’s (2003, 2012) work on knowledge and discourse, and critical discourse analysis methods developed by Fairclough (1989, 2003). Van Dijk (2012) argues that participants in discourses use their pre-existing knowledge resources to interpret new information and to frame statements and assertions. Framing ‘refers to a particular way of representing knowledge, interpreting problems, and providing an evaluative framework for judging how to act’ (Van Herzele, 2004: 198). Following Foucault, Fairclough (1989, 2003) focuses on the constitutive role of language in the dialectical relations between actors, texts and social structures, and on identifying how power influences how information gets framed. We thus suggest identifying and categorizing knowledge types in planning discourse by examining how various actors use knowledge to frame the information they express. In Table 1, and in the detailed descriptions of knowledge types below, we elaborate on the discursive features of each knowledge type.
A typology of knowledges and their discursive characteristics in contemporary planning.
I. Systematized, positivist, quantitative, acontextual knowledge types
The first category includes highly systematized, positivist, abstract and technical forms of knowledge. Ostensibly derived from formal scientific or academic inquiry, these are generally presented as objective, universal and acontextual (Corburn, 2003; Scott, 1998). They involve a certain simplification or ‘narrowing of vision’, which ‘brings into sharp focus certain limited aspects of an otherwise far more complex and unwieldy reality’, thus allowing for ‘a high degree of schematic knowledge, control and manipulation’ (Scott, 1998: 11). These types of knowledge have generally been attributed to professional planners, as they are highly specialized and acquired through extensive training (Davoudi, 2012, 2015). Yet, as we show below, they are now accessible to, and used by, a variety of actors, including non-planner professionals and laypeople.
Perhaps the most rigidly systematized of these knowledges is digital-automated knowledge. A hybrid of human and machine intelligence, human knowledge constitutes its initial inputs, but once encoded into computer languages it can be automated and function independently of further human intervention (Kitchin, 2011). This kind of knowledge incorporates massive amounts of urban data collected by networks of sensors, cameras, antennas and other surveillance techniques (Smith, 2020), which is aggregated into datasets and dashboards (Mattern, 2021) and codified into ‘rules, routines, algorithms and databases’ (Kitchin, 2011: 945). The mechanics of this, which rely heavily on AI, are often opaque and inscrutable to non-programmers (Smith, 2020).
Discursively, digital-automated knowledge represents the city as akin to a computer, and seeks to apply to it normative concepts transposed from the tech world, such as system ‘optimization’ and assessment of ‘key performance indicators’ (Mattern, 2017). Yet, in its attempt to ‘frame the messiness of urban life as programmable and subject to rational order’ (Mattern, 2021: 62), this approach may ignore forms of knowledge which are not easily translatable into lines of code and complexity that cannot be easily tracked using simple metrics (Mattern, 2021), and may be blind to local nuance and context (Peng et al., 2023).
Also recently observed in the literature is what we call neoliberal technocratic knowledge. While presented as ostensibly apolitical, neutral and objective, it selectively draws upon quantitative, financial, contractual and legal ways of knowing, and highlights forms of ostensibly ‘hard knowledge’, while displaying ‘strategic ignorance’ of knowledge types not perceived as growth orientated (Savini and Raco, 2019). Such expertise uses abstract representations of reality based on reductive, compartmentalized models and metrics (Savini and Raco, 2019) in ways calibrated to advance speedy and efficient delivery of projects (Raco et al., 2022).
Notably, both digital-automated and neoliberal technocratic knowledge are generally wielded not by planners but by professionals from other specialized fields, such as software engineers, economists, lawyers and the like (Savini and Raco, 2019), with local knowledge processed through these various prisms, if at all.
Rooted in modernist planning theory and practice, rational-scientific knowledge has been described as the predominant way of knowing in planning (Innes and Booher, 2010; Sandercock, 1998), and remains deeply embedded in contemporary planning discourses (Davoudi, 2012). This approach seeks to ‘bring scientific advice to bear on decisions concerning policies’ (Faludi, 1973: 2), with empirical facts presumed to point the way towards a desired path of action (Faludi, 1973). Knowledge is seen as accruing over time and gradually improving in quality, thus leading to better outcomes (Davoudi, 2015; Rydin, 2007). It is framed and presented in planning discourse as an objective, detached and factual basis for policymaking, guided by instrumental rationality and utilized in pursuit of a utilitarian concern for the public good (Rydin, 2007).
Closely related are technical and procedural knowledge, which relate to the ‘how’ of planning. Technical knowledge involves the specialized skills and know-how, or techne, necessary for creating and understanding plans (Flyvbjerg, 2004). It includes fluency in planning jargon and other systems of symbolic representation, as well as ‘mastery of the means … the tools and technologies’ of plan making (Davoudi, 2015: 320). As it is often acquired in academic studies and in practice, scholars have suggested that it confers membership of the epistemic community of professional planners (Innes and Booher, 2010).
Procedural knowledge involves an understanding of the processes, both formal and informal, through which plans are formulated, advanced and implemented (Alexander, 2005; Rydin, 2007). This approach frames planning as ‘a set of procedures’ (Davidoff and Reiner, 1962: 103), and highlights familiarity with their ins and outs, and how they constrain or enable action (Alexander, 2005), particularly in complex situations in which both written and unwritten sets of rules apply (Healey, 1992a).
In recent years, these knowledge types have become increasingly accessible to lay actors, particularly through social media and media coverage of plans, giving non-professionals greater exposure to formal planning language and rationalities, and undermining planners’ epistemic monopoly (Fox and Margalit, 2024; Margalit, 2022).
II. Interpretive, qualitative, subjective, more-art-than-science knowledge types
The second category is composed of more ‘interpretive’ and self-consciously subjective knowledge types, which are considered more art than science, and are newer to planning discourse (Davoudi, 2015). More qualitative and ‘softer’ (Tamm Hallstrom, 2015), and more honest in their acknowledgement of the values, politics and particularities behind planning (Innes, 1987), these are ‘less about explaining and predicting social events and more about understanding what the social world means for the people who live in it’ (Davoudi, 2015: 320). Friedmann (1987) referred to them as ‘appreciative’ knowledges, as they seek understanding for its own sake, as opposed to the ‘manipulative’ knowledges of the first category above, which seek understanding as a means towards mastery and control.
Some of these knowledge types emerge from the interfaces between planning and other fields. Inter-disciplinary or transdisciplinary knowledge (Hemström et al., 2021), for instance, refers to the synthesis created when specialized planning knowledge and other disciplinary knowledges meet (Davoudi, 2009; Healey, 1992a). Political knowledge involves an understanding of the interests (explicit and implicit) and constraints of elected decision makers, and how these intersect with planning logics (Forester, 1989; Healey, 1992a, 1993). While typically associated with professional planners who must navigate institutional dynamics (Healey, 1992a; Weston and Weston, 2013), laypeople now also wield political knowledge, for instance in grassroots campaigns (see Rogers, 2016).
Other knowledge types address the inherently contingent and value-based aspects of planning’s pretentions to shape the future. Predictive knowledge, or ‘causal knowledge’ (Wildavsky, 1973), involves the systematic examination of different scenarios, and of the complex interactions between the status quo, planning interventions and other social processes (Rydin, 2007). Its expressions acknowledge that multiple different futures are possible (Rydin, 2007), and that uncertainty and contingency are unavoidable in any attempt to ‘control the future by current acts’ (Wildavsky, 1973: 128) in the pursuit of normative goals. This knowledge type, usually associated with professional planners (Rydin, 2007), is now wielded by non-planner professionals as well, such as futurists, corporate smart-city advocates and tech executives (Carr and Hesse, 2020; Savini and Raco, 2019).
Normative-theoretical knowledge addresses questions about what plans ought to do, based on conceptions of ‘good planning’ and a broad grasp of what is realistically achievable through planning processes (Campbell, 2012; Rydin, 2007, 2008). The normative element refers to the desired end states of plans, that is, ‘a view of what the future could and should be like’ (Rydin, 2008: 212). The theoretical element involves ‘grounding in the range of possibilities for the future’ (Rydin, 2007: 65), based on a ‘causal understanding of what is possible’ (Rydin, 2008: 212). Theorists argue that such knowledge is ‘inescapably intertwined with other types of knowledge’ in planning processes (Davoudi, 2015: 322). Its discursive expressions are prescriptive and justified by academic theories, case studies, best practices, etc. (Alexander, 2005; Ozawa and Seltzer, 1999). Nowadays, lay citizens can also deploy these knowledges, alongside professionals, to take value-based stands in grassroots campaigns (Rogers, 2016).
Other knowledge types involve storytelling about potential futures. Narrative knowledge, for instance, involves both the ability to construct compelling stories around plans, and the ability to listen ‘carefully and critically’ to stories told by others (Forester, 1989: 107). Persuasive storytelling in which ‘participants are both characters and joint authors’ (Throgmorton, 1992: 18) helps bridge the gap between knowledge and action by creating shared meanings and imaginaries, and by appealing to moral concerns (Sandercock, 2003). Discursively, storytelling techniques – such as use of dramatic structure, expressive language, humour and irony – are considered more effective for mobilizing support for plans than the language of data or empirical research (Innes, 1987; Van Hulst, 2012). Again, such knowledge is now wielded by diverse actors, including corporations, politicians, activists and smart-city consultants, particularly in media coverage and on social media (Gunder, 2011).
Empathic-emotional knowledge has to do with how such stories are perceived and processed (Alexander, 2005). This involves putting oneself in another’s shoes and ‘knowing with and about others on interpersonal, emotional, and deeply particular levels’ (Campelia, 2017: 541), through an ability to empathize and read between the lines to reveal implicit meanings (Campelia, 2017). Moreover, emotional knowledge may be expressed symbolically (such as through art or fiction) or non-verbally, in ways that might not be immediately recognizable as communication about plans (Sandercock, 2003). While this knowledge type has often been sidelined by planning’s emphasis on scientific rationality (Baum, 2015), it nevertheless plays a role in most, if not all, interpersonal interactions between various actors (Healey, 1992a).
Visual-aesthetic knowledge, meanwhile, relates to how such stories are told visually. It involves the ability to produce, interpret and explain visual representations of plans and three-dimensional spaces (Ewenstein and Whyte, 2007), such as maps, renderings, diagrams, charts and drawings (Shanken, 2018). Long wielded by trained professionals to project seriousness and confer legitimacy on plans (Soderstrom, 1996), such knowledge is increasingly observed in communications between professionals and non-professionals (Van Herzele and van Woerkum, 2011), wielded by laypeople (Boeing, 2021) or deployed by media outlets (Swords and Liu, 2015). Moreover, new technologies such as generative AI now allow anyone to create professional-looking images, while social media allow them to be widely distributed (Luger and Dürr, 2025).
Other knowledge types in this category reach deeper into the subconscious. Reflexive knowledge, for instance, involves knowledge of the self (Rose, 1997). Following Bourdieu, Howe and Langdon (2002) explore how actors’ unconscious biases and unexamined assumptions, which flow from their socioeconomic and cultural background and habitus, can impact planning outcomes in ways that are unintentional or unacknowledged, particularly when interacting with actors from different social backgrounds. Expressions of such knowledge may involve acknowledgement and exploration of divergent identities – including race, class, gender and ethnicity – and how they impact actors’ approaches and understandings (Beebeejaun, 2022).
Tacit knowledge, meanwhile, refers to the embodied knowledge, intuition and judgement that one possesses, without necessarily being conscious of or able to clearly articulate it (Polanyi, 1966). Acquired through experience and trial and error, and conveyed through practice and observation (Schon, 1983), it is associated with both professional planners (Dobson and Dempsey, 2019) and lay actors (Demszky and Nassehi, 2012). However, because of its ‘fuzzy and fluid character’, tacit knowledge is often undervalued in decision-making processes – even when expressed by professionals (Dobson and Dempsey, 2019: 4).
Finally, ethnographic knowledge refers to representations of lay/local knowledge which are produced using empirical research tools such as observation, documentation, discussions and interviews (Rishbeth et al., 2018). Scholars have argued that this kind of knowledge can serve as a ‘bridge’ between systematized and popular knowledges by explaining the motivations and reasoning behind the latter, rather than just capturing their expressions (Mattila et al., 2021). While typically associated with academic researchers, we suggest that lay actors can also wield such knowledge, for instance when practising citizen science.
III. Contextual, popular, experiential knowledge types
The third category is composed of unsystematized, contextual, personal and popular forms of knowledge. In the literature, such knowledge types are often grouped under the catchall term local knowledge. Local knowledge has many nuanced variations, such as ‘metis’, that is, practical knowledge gained through experience (Scott, 1998), and ‘experience-based knowledge’ (Demszky and Nassehi, 2012), which is mostly associated with non-professionals. However, multiple sources point out that planners also acquire knowledge from personal experience, and not only from academic training (see Alexander, 2005; Healey, 1992a).
A variant of local knowledge, indigenous knowledge, is also place based, culturally embedded and experiential, but refers specifically to shared knowledge passed down within groups that inhabit particular geographical areas over extremely long spans of time, with knowledge accruing over the generations (Grenier, 1998). Also sometimes called ‘traditional ecological knowledge’ (Grenier, 1998), such knowledge touches on sustainability issues and the regeneration of natural systems, and is increasingly drawn upon by professional planners (Markkula et al., 2019).
Less familiar, perhaps, is popularized knowledge, which refers to the adaptation of specialized knowledge for lay discourses. In such cases – for instance in media coverage of plans (Margalit, 2022) – expert knowledge is reformulated and recontextualized for non-specialized audiences, with examples, metaphors, definitions and background explanations employed to make meanings more accessible (Calsamiglia and Van Dijk, 2004), thus blurring the boundary between ‘professional’ and ‘lay’ knowledge. Technical information and language are minimized, while human and social details (e.g. personal stories and anecdotes) are emphasized (Calsamiglia and Van Dijk, 2004). Scholars note that the partial understandings of complex topics created by popularized knowledge may provide the illusion of causal understanding (Rozenblit and Keil, 2002), as ‘people with substantial deficits in their knowledge or expertise’ are unaware of the extent of their own ignorance, that is, the ‘Dunning–Kruger effect’ (Dunning, 2011: 260). Thus, discursive expressions of popularized knowledge may tend towards overconfidence and overestimation of lay understandings of complex topics, while undervaluing actual expertise (Scharrer et al., 2017).
IV. Knowledge types based on post-truth, manipulation of meanings
The fourth category is defined, in our interpretation, by the reinterpretation and active manipulation of meanings, based on underlying power relations and interests. This may draw upon post-truth, or simply wilful distortion and ‘strategic ignorance’ (Savini and Raco, 2019), which enable various actors to array their arguments in ways that suit their interests or ideology.
Flyvbjerg’s (1998) concept ‘realrationalitat’, or ‘real rationality’, for instance, describes a falsified form of rational-scientific knowledge in which the knowledge–action sequence is reversed: first a desired course of action is chosen, and then the knowledge necessary to justify it is created ex post facto. Rather than investigate reality as it is, real rationality seeks to define reality in ways that suit a preconceived agenda, that is, ‘rationalization presented as rationality’ (Flyvbjerg, 1998: 2). Similarly, particularist knowledge refers to selective and self-interested perspectives used to promote private interests through public policy (DuPuis and Gareau, 2008). Expressions of such knowledge tend to reject arguments that purport to represent the public good, while challenging the universalist nature of technocratic knowledge and portraying technical experts as just another interest group (DuPuis and Gareau, 2008). In both cases, an actor (e.g. a developer, politician or grassroots organization) ‘ignores or suppresses that knowledge which does not serve’ their goals (Flyvbjerg, 1998: 319).
Populist knowledge is an alternative way of knowing based on the shared beliefs of populist epistemic communities (Nawrocki, 2024). Illiberal populists tend to reject technocratic and expert knowledge in favour of expressions of ‘common sense’ that claim to draw legitimacy from the popular will (Müller, 2017; Nawrocki, 2024). Such claims are often based on post-truth, ‘alternative facts’ and conspiracy theories (Caprotti et al., 2024). Populist discourse is ‘highly emotional and simplistic’ and ‘directed at the “gut feelings” of the people’ (Mudde, 2004: 542), while complex and reasoned arguments put forward by trained planners are dismissed as counterintuitive (Filion, 2011). Its expressions may include overly simplistic or exaggerated rhetoric, as well as impassioned and uncompromising assertions, which demonize or scapegoat perceived opponents (Sager, 2020).
Recent manifestations of populist knowledge (mainly from the political right) have been observed in pro-car campaigns (Filion, 2011; Yazar, 2024), backlashes against urban climate and justice policies (Yazar, 2024), regional planning exercises (Frick, 2013), grassroots backlashes inspired by conspiracy theorizing about concepts such as Agenda 21 (Berry and Portney, 2016) and the 15-minute city (Glover, 2024), anti-housing NIMBY campaigns and popular mobilizations against immigrants, and even in debates over ‘traditional’ versus modern architectural styles (Fainstein and Novy, 2025).
A spectrum of knowledge types
Our typology demonstrates the blurring of distinctions between ‘professional’ and ‘lay’ or ‘local’ ways of knowing. The research cited above shows how professionals can wield knowledges generally considered ‘local’ (e.g. ethnographic, experiential), while lay people can access ‘professional’ knowledges (e.g. popularized, visual-aesthetic, narrative). Meanwhile, ‘professional’ knowledge is not exclusive to planners, as multiple knowledge types (e.g. transdisciplinary, political) arise from the interactions between planning actors and other professionalized disciplines, while others are associated primarily with non-planner professionals (e.g. digital-automated, neoliberal technocratic), or not necessarily associated with any particular actor (e.g. populist, tacit).
While these knowledge types were presented in Table 1 in a linear fashion, we believe they are better understood as being arranged in a horseshoe shape or along a circular spectrum – a shape reminiscent of a colour wheel – in which the opposite poles converge but don’t necessarily meet. This approach is based on recent research showing how ostensibly divergent streams such as technocracy and populism (Bickerton and Accetti, 2021) are increasingly merging in novel ways, and the realization that at both poles (e.g. in generative AI’s ‘hallucinations’ and in populism’s post-truth discourse), objective, shared reality is undermined.
In planning, this kind of overlap can lead to the blending together of various different knowledge types, thus creating novel hybrids, particularly at the edges of the spectrum. For instance, a recent study on conspiracy theories linking Covid-19 and 5G cellular antennas (Flaherty et al., 2022) showed how lay actors utilized specialized tools for spatial data analysis (i.e. technical knowledge) to promote a narrative based on ‘alternative facts’ (populist knowledge) on social media. Likewise, Fox and Margalit (2024) demonstrated how technical and technocratic knowledge can be used to convey populist messaging on plans through mass media.
Conclusion
In his work on power-knowledge, Foucault (1980: 82) distinguished between dominant forms of knowledge in societies and subjugated forms, such as ‘local popular knowledges’. Scott (1998) applied this binary view of knowledge to the modern state, while planning scholars (Corburn, 2003; Friedmann, 1973) applied it to planning. Some theorists (Davoudi, 2012; Innes, 1987) further subdivided professional planning knowledge into an additional binary: positivist and interpretive. Theorists of the ‘communicative turn’ (Healey, 1992a; Sandercock, 1998) argued that ‘knowledge is inherently multiple’ (Rydin, 2007: 54). Within this multiplicity, however, scholars largely maintained the distinction between professional and lay-local knowledge, while power-knowledge critiques primarily addressed dynamics between professionals and lay actors.
In this article, we have sought to build upon this scholarship, while departing from the professional–local knowledge dichotomy. We have argued that due to major shifts in technology, media, society and planning itself, this dichotomy now limits our understanding of contemporary knowledge and power–knowledge dynamics. Instead, we have proposed a method of defining and classifying these multiple ways of knowing by their discursive expressions, rather than by the identity of the knower.
We have compiled these knowledges – as well as several distinct, recently identified knowledge types – into an updated typology, and explored how various professionals (planners and non-planners) and lay actors wield them in contemporary arenas. We demonstrated how contemporary ways of knowing are vastly more varied than the oft-cited professional–local knowledge dichotomy would imply, and showed how knowledge types can no longer be exclusively associated with specific actors, and in some cases even merge and combine to create novel hybrids.
Our approach introduces additional layers of nuance and complexity into long-standing critiques of power–knowledge conflicts between planners and laypeople (Friedmann, 1973; Sandercock, 1998) and raises new questions. For instance, how might conceptions of epistemic injustice (Fricker, 2007) change in a world in which ostensibly disempowered lay actors can now empower themselves with various forms of professional knowledge? Additionally, how might knowledges based on post-truth present new openings for upending entrenched power–knowledge hierarchies?
Moreover, the convergence of phenomena such as populism and generative AI presages new challenges to established planning knowledge, and to planners’ epistemic authority. Just as, under modernism, lay-local knowledges were suppressed in favour of professional knowledge (Scott, 1998), and neoliberalism devalued ‘interpretive’ and ‘soft’ knowledges in favour of technocratic pro-growth knowledges (Savini and Raco, 2019), the combined forces of illiberal populism and AI (wielded by Big Tech) may seek to render human planning knowledge superfluous altogether through automation. How might this impact our capacity for agency and collective action, for example, in the face of the Anthropocene polycrisis?
To conclude, we hope that this work will contribute to a more nuanced and up-to-date epistemology in urban planning. By challenging long-standing assumptions, we seek to inspire a renewed debate on knowledge and power–knowledge relations in contemporary planning. We also hypothesize that such power–knowledge dynamics will vary by geographical, demographic, socio-economic and political contexts. We hope this approach will continue to be refined in future research and debates on power–knowledge relations among planners, other professionals, laypeople and additional actors in a changing world. We believe such work would not only improve our understanding of knowledge in planning but also potentially improve how that knowledge is communicated in planning discourses.
Footnotes
Acknowledgements
We would like to thank the Israel Science Foundation for its generous support of our research. We are grateful to the anonymous reviewers and the Debates editor at Urban Studies for their thoughtful feedback, which helped us refine and better articulate our ideas. Thanks are due to Rachelle Alterman for her reasoned advice and support along the way. Thanks to Mike Raco and Tovi Fenster, who first suggested that we consider molding these ideas into an article. Finally, we are grateful to our families for their boundless patience and support. To Hadas, thank you for so many things.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Israel Science Foundation 2270/22.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.