| Abstract: | Graphical Item Analysis (GIA) visually displays the relationship between the total score on a test and the response proportions of the correct and false alternatives of a multiple-choice item. The GIA method provides essential and easily interpretable information about item characteristics (difficulty, discrimination and guessing rate). Low quality items are easily detected with the GIA method because they show response proportions on the correct alternative which decrease with an increase of the total score, or display response proportions of one or more false alternatives which do not decrease with an increase of the total score. The GIA method has two main applications. Firstly, it can be used by researchers in the process of identifying items that need to be excluded from further analysis. Secondly, it can be used by test constructors in the process of improving the quality of the item bank. GIA enables a better understanding of test theory and test construction, especially for those without a background in psychometrics. In this sense, the GIA method might contribute to reducing the gap between the world of psychometrists and the practical world of constructors of achievement tests. |
