The short-answer and the multiple-choice items have been the most popular item formats in student assessments. In this study, we made comparisons of item characteristics (i.e., difficulty and discrimination) and item/test information functions between the two item formats by using a new testing system called the Constructive Multiple-choice Test. Assessments using the Constructive Multiple-choice Tests for elementary and undergraduate students showed that there were significant differences between the short-answer and the multiple-choice items in terms of item difficulty /discrimination and item/test information. That is, the short-answer items tended to be more difficult and discriminating and to have more information in general, whereas the multiple-choice items were somewhat more useful in distinguishing lower ability examinees. Limitations of the current study and suggestions for further research were discussed.