Gauging the effectiveness of specific teaching strategies remains a major topic of interest in science education. Inquiry teaching among others has been supported by extensive research and recommended by the National Science Education Standards. However, most of the empirical evidence in support was collected in research settings rather than in…

Differential item functioning (DIF) can undermine the validity of cross-lingual comparisons. While a lot of efficient statistics for detecting DIF are available, few general findings have been found to explain DIF results. The objective of the article was to study DIF sources by using a mixed method design. The design involves a quantitative phase…