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2022– : Research associate and PhD student at GESIS Mannheim,department SDM, team SDD / ZIS
2021–2022: Research associate at GESIS Mannheim,department SDM, team SDD, third-party funded project Foster
2010–2020: Extra-occupational studies of B.Sc. and M.Sc. Psychology at the FernUniversität in Hagen, research focus on Industrial and Organizational Psychology as well as Educational Psychology
Master Thesis: "Online Test Divergent Thinking – Short Version (OTD-S): Validation of a browser-based screening instrument for the measurement of creativity" (2019)
Bachelor Thesis: "Divergent age effects in intelligence diagnostics: Re-analysis of empirical data." (2015)
1998–2003: Studies of Graphic- and Communication Design, Lazi Akademie Esslingen; Diploma Thesis: "DIN standards – the measure of all things. An exhibition concept."

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• Documentation of standard items and scales from large survey programs (e.g. FReDA, ISSP, ALLBUS, ESS) in ZIS
• Participation in the (further) development of quality and documentation standards
• Contributing to the further development of the ZIS website, in particular improving content retrievability and presentation of standard items and scales
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Measurement and modeling of cognitive (intelligence, creativity) and non-cognitive abilities (personality)
Consideration of developmental (e.g., biological age) and survey effects (instruction and timing) on data and outcome quality
Evaluation of open-ended question formats (standardized, automated) in online assessments.
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Journal article

Lechner, Clemens, Thomas Knopf, Christopher Napolitano, Beatrice Rammstedt, Brent Roberts, Christopher Soto, and Marion Spengler. 2022. "The Behavioral, Emotional, and Social Skills Inventory (BESSI): Psychometric properties of a German-language adaptation, temporal stabilities of the skills, and associations with personality and intelligence." Journal of Intelligence 10 (3): 63.

Danner, Daniel, Beatrice Rammstedt, Matthias Blümke, Clemens Lechner, Sabrina Berres, Thomas Knopf, Christopher Soto, and Oliver P. John. 2019. "Das Big-Five Inventar 2: Validierung eines Persönlichkeitsinventars zur Erfassung von 5 Persönlichkeitsdomänen und 15 Facetten." Diagnostica 65 (3): 121-132. doi:

Lechner, Clemens, Ai Miyamoto, and Thomas Knopf. 2019. "Should students be smart, curious, or both?: Fluid intelligence, Openness, and interest co-shape the acquisition of reading and math competence." Intelligence 76. doi:

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Groskurth, Katharina, Thomas Knopf, Melanie Partsch, Isabelle Schmidt, and Matthias Blümke. 2020. Stata Code for the Development and Validation of Measurement Instruments in the Social Sciences: Psychometric Analyses (Dimensionality, Reliability, Measurement Invariance). doi:

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Other article

Knopf, Thomas, Julian Urban, and Clemens Lechner. 2022. "Soziale, emotionale und selbstregulatorische Kompetenzen: Welche Kompetenzen wollen Eltern durch die Schule vermittelt sehen? Welche Kompetenzen schreiben sich Jugendliche zu?" In Projektbericht für die Bertelsmann-Stiftung,