Social Media use variables (duration of membership, frequency, activities, motives, self-disclosure, strategic networking,…): Self-developed
Resource Generator (W1-5;8): Self-developed (in discussion with Martin van der Gaag, updated earlier resource generators )
Van der Gaag and Snijders (2005).
Informational benefits: Wickramasinghe and Weliwitigoda (2011)
Career satisfaction: Greenhaus, Parasuraman, and Wormley (1990)
Life satisfaction: shorter and adapted version of Priebe, Huxley, Knight, and Evans (1999)
Civic engagement: loosely based and adapted to Dutch context from Valenzuela, Park, & Kee, (2009)
Social support: UCLA-SSI Dunkel-Schetter, Feinstein, and Call (1986) adapted to online/offline and tie strength
Stress: four items from Cohen, Kamarck & Mermelstein (1983)
Generalized trust: similarities with European social survey
three item measure used in 2002 and 2004 (Reeskens & Hooghe, 2008)
Obsessive/harmonious passion (W1-5): Vallerand et al. (2003)
Nomophobia (W6-8): Yildirim and Correia (2015)
Networking (W6+7): German short version of Wolff and Moser, (2006), presented at AOW-Tagung (Wolff, Spurk, & Teeuwen, 2015)

Cohen, S., Kamarck, T., & Mermelstein, R. (1983). A global measure of perceived stress. Journal of Health and Social Behavior, 24(4), 385–396.
Dunkel-Schetter, C., Feinstein, L., & Call, J. (1986). UCLA social support inventory. Unpublished Manuscript, University of California, Los Angeles.
Greenhaus, J. H., Parasuraman, S., & Wormley, W. M. (1990). Effects of Race on Organizational Experiences, Job Performance Evaluations, and Career Outcomes. Academy of Management Journal , 33(1), 64–86 doi:10.2307/256352
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Vallerand, R. J., Blanchard, C., Mageau, G. A., Koestner, R., Ratelle, C., Léonard, M., … Marsolais, J. (2003). Les passions de l’âme: On obsessive and harmonious passion. Journal of Personality and Social Psychology, 85(4), 756–767. doi:10.1037/0022-3514.85.4.756
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Wolff, H.-G., Spurk, D., & Teeuwen, S. (2015). Entwicklung und Validierung einer Networking-Kurzskala. In T. Rigotti, V. C. Haun, & C. Dormann (Eds.), Menschen, Medien, Möglichkeiten [People, media, possibilities] 9. Fachgruppentagung Arbeits-, Organisations- und Wirtschaftspsychologie der DGPs in Mainz (p. 134). Lengerich: Pabst Science Publishers.
Yildirim, C., & Correia, A.-P. (2015). Exploring the dimensions of nomophobia: Development and validation of a self-reported questionnaire. Computers in Human Behavior, 49, 130–137. doi:10.1016/j.chb.2015.02.059