Designers often face situations where the only way forward is through the exploration of possibilities. However, there is a critical disconnect between understanding of how designer's think and act in such situations. We address this disconnect by proposing and testing (via protocol analysis) the cognitive co-evolution model. Our model comprises a new approach to co-evolutionary design theory by explaining both the progression of the process itself and the creation of design outputs via an interplay between metacognitive perceived uncertainty, cognition, and the external world. We thus connect explanations of how designers think with descriptions of how they act. We provide a foundation for connecting to other theories, models, and questions in design research via common links to cognition and metacognition.

The increasingly transdisciplinary context of design, where designers collaborate with other disciplinary and domain experts, means there is a growing need to evidence the effectiveness of design methods. We address this need in two ways. First, we propose a ‘chain of evidence’, from motivation to claims, operationalising this in a systematic assessment framework. Second, we systematically review current design method research. Our results reveal that while all links in the chain of evidence are reported across the literature and best practices can be identified, no individual paper either reports all links or consistently achieves best practice. Our framework and results demonstrate the need for standards of evidence in this area, with implications for design method research, development, education, and practice.

Behavioural design is an important area of research and practice key to addressing behavioural and societal challenges. Behavioural design reflects a synthesis of design and behavioural science, which draws together aspects of abductive, inductive, and deductive reasoning to frame, develop, and deliver behaviour change through purposefully designed interventions. However, this synthesis creates major questions as to how methods are selected, adapted, and used during behavioural design. To take a step toward answering these questions we conducted fifteen interviews with globally recognised experts. Based on these interviews we deliver three main contributions. First, we provide an overview of the methods used in all phases of the behavioural design process. Second, we identify behavioural uncertainty as a key driver of method use in behavioural design. Third, we explain how this creates a tension between design and scientific concerns—related to interactions between abductive, inductive, and deductive reasoning—which must be managed across the behavioural design process. We bring these insights together in a basic conceptual framework explaining how and why methods are used in behavioural design. Together these findings take a step towards closing critical gaps in behavioural design theory and practice. They also highlight several directions for further research on method use and uncertainty as well as behavioural design expertise and professional identity.

Behavioural Design is a critical means to address human behaviour challenges including health, safety, and sustainability. Practitioners and researchers face difficulties in synthesising relevant perspectives from across fields, as behavioural challenges are complex and multi-dimensional. This study takes a three step theory-building approach. First, we review behavioural theories and models primarily rooted in psychology, and discuss them in relation to design perspectives to identify parameters key to behavioural design. Next, we synthesise previously fragmented behavioural and design parameters and propose the Behavioural Design Space (BDS) framework, including: Cognition, Ability, Motivation, Timing, Social, and Physical Context. Last, as a demonstration of its use, we apply the BDS framework as lens on observed expert behavioural designer’s ideation. Our findings are twofold. First, the synthesis of generic behavioural and design parameters allow us to investigate expert behavioural designer’s ideation across five diverse cases. This illustrates the BDS’ potential of providing relevant overview across diverse domains. Second, the expert behavioural designers observed often utilised the less abstract parameter, Physical Context, and favoured low variation of parameters within concepts. This point to a need for support to help designers discover potential pitfalls and blind spots, as well as further study of behavioural design ideation.

Design methods capture key procedural knowledge, central to design process, practice, and education. However, a more robust explanation of the method phenomenon is needed. We move towards answering this need by proposing, and quantitatively testing, a Method Content Theory; addressing i) how methods function in context; ii) the elements of method content i.e. Method Framing, Method Rationale, Method Goal, Method Procedure, and Method Mindset; and iii) predictors of method performance. We provide initial quantitative validation for the proposed theory demonstrating strong predictive power for methodological performance indicators. We build on this to define a future research agenda. Our results have implications for research, education and practice, along with the potential for actionable insights in design methodology, method development and validation.

Ideation is simultaneously one of the most investigated and most intriguing aspects of design. The reasons for this attention are partly due to its importance in design and innovation, and partly due to an array of conflicting results and explanations. In this study, we develop an integrative perspective on individual ideation by combining cognitive and process-based views via dual-process theory. We present a protocol and network analysis of 31 ideation sessions, based on novice designers working individually, revealing the emergence of eight idea archetypes and a number of process features. Based on this, we propose the Dual-Process Ideation (DPI) Model, which links idea creation and idea judgement. This explains a number of previously contradictory results and offers testable predictive power.

Behavioural design is a critical means to address challenges surrounding human behaviour. However, practitioners and researcher face difficulties in synthesising relevant perspectives from across fields as behavioural challenges are complex and multi-dimensional. Taking a theory-building approach, this study explore how expert behavioural designers navigate in this complex design space by examining the creative outcome of their current ideation practice. The findings reveal that the designers favour ‘holding’ out of the four identified ideation patterns: holding, shifting, pairing, and mixing.

Professional Identity (PI) is a social- and self-perceptive construct that describes how people understand themselves as professionals. PI guides professional development by shaping professionalism, role assumptions, responsibilities, values, and behaviour; and is a critical factor in professional performance and wellbeing. As such, PI has significant implications for how we support engineering designers in professional development and direct their social- and self-understanding. However, no current research provides a complete picture of PI elements important for Designers’ Professional Identity (DPI). This study aims to review and synthesise PI elements, currently discussed separately in the design literature, in order to propose a holistic understanding of DPI. Based on an extensive literature review, we find that DPI consists of two distinct sets of elements: Personal Attributes (PA) and Design Skills (DS). We present these two sets of elements in terms of meaning, possible relations between them, and their influence on DPI development. In addition, we propose multiple directions for future research.

Uncertainty drives project activity in new product development (NPD), and its resolution is crucial to project performance. However, there is a major gap in understanding the causal links between different uncertainty types and the project activities they trigger. Engineering managers lack guidance on how best to respond to different uncertainty types. We close this gap by experimentally contrasting responses to two uncertainty types central to NPD: technical and organizational uncertainty. We describe responses with respect to core engineering project activities: representation, information, and knowledge sharing. We present evidence from an experiment involving 50 professionals and 74 master's students. The results show that uncertainty type has a significant effect on activity response, and that there is a significant ordering effect within this response. Based on the identification of a new response type, change of situation, our findings show that technical uncertainty drives change of situation and representation activity, while organizational uncertainty drives information- and knowledge-sharing activities. This provides the basis for three main contributions of this article. First, we identify “change of situation” as a new type of response to uncertainty in NPD. Second, we describe different responses to technical and organizational uncertainty. Third, we characterize an ordering effect in responses to uncertainty.

Behavioural design has emerged as a critical new area of research and practice. However, despite the development of extensive lists of possible problem features and suggested solution principles there is little guidance on how these should be connected. Therefore, in this work we systematically examine interactions between major problem features and solution principles, based on an analysis of 218 behavioural design interventions drawn from 139 cases across design domains and foci. This forms the basis for a number of contributions. First, we bring together behavioural and designerly perspectives on problem characterisation via two proposed problem features: change
demand and behavioural constraint, related in a two-by-two framework. Second, we synthesised recommendations from across domains and foci to operationalise a list of 23 solution principles relevant to designers. Third, we link these insights in a proposed Behavioural
Problem/Solution (BPS) matrix. Further, we identify a number of potential systemic challenges in the reporting and evidencing of behavioural design interventions. Together, these insights substantially extend both theory and practice surrounding problem-solution mapping in behavioural design, and form a foundation for further theory development and synthesis in this area.

Uncertainty is central to engineering design and new product development (NPD). While there has been substantial focus on dealing with uncertainty in technical systems and design information, how engineering designers react to and manage uncertainty is also critical to performance. However, an important gap remains in understanding what activities NPD teams engage in based on the specific uncertainty types they face. This gap is investigated via a conceptual framework detailing four uncertainty types (technical, organisational, resource and market) and three project activities (information, knowledge sharing and representation). Evidence is presented from two engineering design cases with 45 interviews, observations, and secondary data. Based on this, specific links are described between uncertainty type and project activity as follows: technical uncertainty drove representation activity, organisational uncertainty drove knowledge sharing activity, resource uncertainty drove knowledge sharing activity, and market uncertainty drove information activity. These findings are developed into a number of propositional relationships between the four uncertainty types and specific project activities, which form the basis for a number of implications for engineering design research and practice.

Design research faces a critical 'impact gap' where the potential for scientific and practical impact is yet to be fully realised. A key means of bridging this gap is the adoption of fundamental theory from other fields to support clarification and synergy in design research. In this paper we examine one of the main candidates for adoption: dual-process theory of cognition. Cognition forms a common element across much of the design literature and leads to fundamental dual-process theories of reasoning. While dual-process theory has started to be recognised in design research, its widespread recognition and potential utility have not been widely explored. Following a conceptual theory development approach we identify and logically describe interactions between dual-process theory and design research. We conclude the paper with a proposition of a design research framework with a core rooted in dual-process theory, and based on this, an agenda for theory-driven design research. This contributes to the debate on how to improve impact, and theoretical and scientific rigour in design research, and provides a concrete agenda for discussion and development within the community.

Designers’ Professional Identity (DPI) is a social- and self-perceptive construct that describes how designers understand themselves as professionals. DPI guides development throughout a designer’s career by shaping professionalism, role assumptions, responsibilities, values and behaviour. DPI links two sets of elements: Personal Attributes and Design Skills. However, little is known about how designers perceive themselves in comparison to other critical actors affecting DPI: educators and managers. While differing perceptions between educators and managers is acknowledged, there is a critical need for more detailed understanding of these differences in comparison to how designers perceive themselves. This study uses semi-structured interviews with designers, design professors, and design managers to shed light on differences in perception of DPI. Analysis of the data highlights critical differences between the three groups. We described these differences with respect to three thematic perspectives on DPI: Technique, Creativity and Rapport. This provides important contributions to understanding DPI, with implications for education and practice.

Core elements of design work include the development of problem/solution
understanding, as well as information and knowledge sharing activities. However, their interrelationships have been little explored. As such, this work aims to take the first steps towards a more integrated evaluation and description of the interaction between understanding and activity, based around co-evolutionary transition events; and start to answer the question: How can the link between co-evolution and activity be systematically characterized as a foundation for a more fundamental description of design activity? A
protocol analysis is used to provide the basis for characterization of different types of coevolutionary transition event. A number of distinct event types are described and significant differences in information use and team engagement are identified across transition events. Bringing these findings together, we propose a unitary model of the interaction between activity and understanding around co-evolutionary transition events. This has a number of implications for future theory building and testing in both design activity and wider design
research.