Data collected within 1) the PREMIUM master honors program, and 2) through online groups on LinkedIn. The goal of the data was to validate an instrument to measure adaptive expertise. The data is used in this article: Bohle-Carbonell, K., Könings, K. D., Segers. M. and van Merrienboer, J. J. G. (2015). Measuring Adaptive Expertise: Instrument Validation. European Journal of Work and Organizational Psychology, 25 (2), doi: 10.1080/1359432X.2015.1036858 The article is available at: http://www.tandfonline.com/doi/abs/10.1080/1359432X.2015.1036858?journalCode=pewo2