Media type: E-Article Title: Teacher knowledge experiment: Testing mechanisms underlying the formation of preservice elementary school teachers’ pedagogical content knowledge concerning fractions and fractional arithmetic Contributor: Tröbst, Steffen; Kleickmann, Thilo; Heinze, Aiso; Bernholt, Andrea; Rink, Roland; Kunter, Mareike imprint: American Psychological Association (APA), 2018 Published in: Journal of Educational Psychology Language: English DOI: 10.1037/edu0000260 ISSN: 1939-2176; 0022-0663 Keywords: Developmental and Educational Psychology ; Education Origination: Footnote: