The results showed that the retrieval practice provided by testing/quizzing functioned as a desirable difficulty for students that was not only limited to specific information, but also conceptually similar information. Benefits of this desirable difficulty are thought to be from retrieval practice during quizzes, the quizzes being a source of information for students to know what concepts they need to study, the quizzes encouraging students to engage in spaced study, and additional learning at the time of feedback. Benefits could also have been seen during quizzes, when information about concepts that were incorrect alternatives had to be processed when deciding which choice was correct. This could then lead to strengthening associations between alternatives and information about those alternatives that could have been on the final exam.