The principle behind On Numbers' fan difficulty index is a simple one: It's easier to root for a professional sports team that wins. Ratings were generated for the 122 teams in the four major sports: ...

A study was conducted to investigate the effect on concept difficulty of: a.) the number of defining attributes, and b.) the level of conceptualization (LC) of the concepts' attributes. One hundred ...

In this study, the authors explored the importance of item difficulty (equated delta) as a predictor of differential item functioning (DIF) of Black versus matched White examinees for four verbal item ...