A Comparison of Written and Oral Methods of Testing in Science

The investigation set out to determine whether there were differences in the assessment of student understanding as measured by written tests, on the one hand, and oral tests, on the other. Three sets of questions were devised in both written and oral formats, and administered to different random samples of students taken from secondary schools in Greece and universities in Portugal. For two sets of questions, the groups taking the oral format had significantly higher mean scores than those taking the written format. In the third set, there was no significant difference between the mean scores from the two test formats. In no case was there significant interactions involving the sex or chronological age of the students.