Empirical studies have revealed that teachers face problems when assessing task difficulty for their students. By drawing on research that focuses on how individuals assess what others know, we argue that these difficulties are a consequence of the imputation of one's own knowledge to others (i.e., social projection). In particular, we tested the…

Expectancy-value theory (EVT) proposes that students' appraisals of success expectancy and task value are the main drivers of their study and career choices. Dimensional comparison theory proposes that these beliefs are themselves affected by students comparing their ability across different domains. However, only a few studies have aimed to…

This research study was specifically concerned with the development, testing, and revision to an instructional theory for studying the mathematical concepts of equivalence and equation solving with multiple representations and multiple tools. Following a design research approach, a collaborative teaching experiment was conducted with a ninth-grade…