The term "Co-Design" is a very popular term in the fields of UX and Accessible Design, but it appears to mean different things to different people. Therefore, this research explores the evolution of the term “Co-Design” over the past 30 years, to see whether or not the term has remained consistent or if it has become either more specific or more general in that time. The term “Co-Design” and some variations of it were searched for in various bibliographical repositories for each year 1994-2023 to locate a highly cited paper (that is not behind a paywall) to locate unique definitions that would be available to all academics each year. The definitions will be explored to identify whether they use the term “Co-Design” as a general term, or a specific set of methodologies. It will also identify whether different geographic regions use the term in distinct ways, as well as whether the term is used differently in different academic disciplines.

Different researchers have suggested it means different things, with some expressing concern that it might be a mere buzz word (Rolan et al., 2019), whilst others identify specific tools and techniques associated with co-design (Zivojnovic, et al., 1996; Akach et al., 2021). A generally accepted definition by Sanders and Stappers (2008) indicated that co-design is the “creativity of designers and people not trained in design working together in the design development process”, but we will see in this analysis that the term means a range of things to a range of researchers.

To explore the meaning of “Co-Design” a thematic search (Alhojailan, 2012) of international literature was conducted to review key literature in this domain. The design and scope of the searching process was focused on identifying highly cited research papers for each year in the range 1994-2023 that are not behind a paywall, to locate unique definitions that would be freely available to all academics each year.

The bibliographical repositories used were:
- The Internal College Library Database.
- Google Scholar.
- Taylor & Johnson Online.
- The Online Learning Journal.

The associated search terms used were:
- “Co-Design”
- “CoDesign”
- “Co-Creation”
- “Co-Construction”
- “Co-Production”
- “Cooperative Design”
- “Co-operative Design”
- “Collaborative Design”
- “Participatory Design”
- “Open Design”
- “User Participation”
- “User-Centred Design”
- “User-Centered Design”

Inclusion and exclusion criteria were established and adhered to, based on locating highly cited research papers that included a clear definition of “Co-Design” for each year in the range 1994-2023, noting that only papers that were freely available (i.e. not behind a paywall) were considered. This was designed to ensure that all the definitions presented here were freely available to researchers once their papers were published. Based on these criteria, the thirty papers that are best representative of each year 1994-2023 will presented, which offers a definition of Co-Design that reflects the current thinking on Co-Design at the time of publication. In some of the definitions presented below additional text is included to ensure a clear understanding of the context of the definition will be given.

Keywords: Co-Design, Inclusion.