\input zb-basic
\input zb-matheduc
\iteman{ZMATH 2013b.00461}
\itemau{Izsak, Andrew; Jacobson, Erik; de Araujo, Zandra; Hawley Orrill, Chandra}
\itemti{Measuring mathematical knowledge for teaching fractions with drawn quantities.}
\itemso{J. Res. Math. Educ. 43, No. 4, 391-427 (2012).}
\itemab
Summary: Researchers have recently used traditional item response theory (IRT) models to measure mathematical knowledge for teaching (MKT). Some studies, however, have reported subgroups when measuring middle-grades teachers' MKT, and such groups violate a key assumption of IRT models. This study investigated the utility of an alternative called the mixture Rasch model that allows for subgroups. The model was applied to middle-grades teachers' performance on pretests and posttests bracketing a 42-hour professional development course focused on drawn models for fraction arithmetic. Results from psychometric modeling and evidence from video-recorded interviews and professional development sessions suggested that there were 2 subgroups of middle-grades teachers, 1 better able to reason with 3-level unit structures and 1 constrained to 2-level unit structures. Some teachers, however, were easier to classify than others. (ERIC)
\itemrv{~}
\itemcc{D69 C49 F40 F70}
\itemut{psychometrics; professional development; item response theory; knowledge base for teaching; pedagogical content knowledge; middle school teachers; arithmetic; mathematical knowledge for teaching; fractions; quantities}
\itemli{doi:10.5951/jresematheduc.43.4.0391 http://www.nctm.org/publications/article.aspx?id=33415}
\end