The time on task effect in reading and problem solving is moderated by task difficulty and skill: Insights from a computer-based large-scale assessment
Journal of Educational Psychology (2014) - Comment
doi: 10.1037/a0034716  issn: 1939-2176  issn: 0022-0663 

Frank Goldhammer, Johannes Naumann, Annette Stelter, Krisztina Tóth, Heiko Rölke, Eckhard Klieme