User-Centered Design Competencies - Construction of a Competency Model

User-Centered Design (UCD) has become an established practice for designing new and better products and services. These products and services should have good usability, elicit positive user experience, and thereby help people enjoy using them for both work and play. UCD has evolved from its origins in basing a design on users' wants and needs, to increasingly engaging more stakeholders in the design process. Managing user involvement and design team composition requires a solid understanding of the participants' competencies, i.e. their knowledge, skills and abilities, in order to use their strengths in the best possible way. What are the necessary UCD competencies? How can these UCD competencies be measured or assessed? How can the use of a competency model help UCD projects? This thesis introduces competencies and competency models in order to lay a theoretical foundation for the development of the UCD Competency Model. The proposed model is based on seminal works of User-Centered Design literature and on experience gained from the processual and methodological developments described in the published papers (Publications I-VIII). It describes twelve of the most relevant competencies for UCD in the four categories of User Strengths, Soft Skills, Designer Strengths, and Hard Skills. The model provides tools to assess and visualize each participant's expertise in each competency in order to form a picture of the entire project team's strengths and potential gaps in their resources. The UCD Competency Model was validated with 24 industry practitioners of User-Centered Design with a total of 261 years of work experience. Based on the quantitative analyses (means, deviations, reliability checks, exploratory factor analysis and correlations) and qualitative analyses (text condensation, affinity diagrams and card sorting) of the questionnaire data, the UCD Competency Model is shown to include the most relevant aspects of UCD, to be statistically reliable and valid, and to be able to reliably differentiate project participants with respect to appropriate competency levels.