To examine the impact of transitioning 4th grade reading comprehension assessments to the computer, 219 fourth graders were randomly assigned to take a one-hour reading comprehension assessment on paper, on a computer using scrolling text to navigate through passages, or on a computer using paging text to navigate through passages. This study examined whether presentation form affected student test scores. Students also completed a computer skills performance assessment, a paper based computer literacy assessment, and a computer use survey. Results from the reading comprehension assessment and the three computer instruments were used to examine differences in students test scores while taking into account their computer skills. ANOVA and regression analyses provide evidence of the following findings: 1. There were no significant differences in reading comprehension scores across testing modes. On average, students in the paper group (n=75) answered 58.1% of the items correctly, students in the scrolling group (n=70) answered 52.2% of the items correctly, and students in the whole page group (n=74) answered 56.9% of the items correctly. Te almost a 6% point difference in scores between the paper and scrolling groups was not significant at the p less than 0.05 or p less than 0.1 level. Although the results suggest that, across all students, the modal effect is not statistically significant, this finding may be due in part to the unusually high computer access and higher socio-economic status of the sample. 2. There were no statistically significant differences in reading comprehension scores based on computer fluidity and computer literacy, but a pattern in performance suggests that students are disadvantaged by the scrolling text mode, particularly students with lower computer skills. 3. The majority of students who took the reading test on a computer indicated that they would prefer to take the test on computer. Although this sample did not include many students who had limited prior computer experience, the survey responses, completion rates, and student observations provide evidence that computer anxiety generally did not interfere with students' ability to take the assessment. 4. Providing highlighters and review markers is useful for some students. The results of this study suggest that further research is warranted to understand differences in scores when reading comprehension assessments are administered via computer to a larger and more diverse group of students. (Contains 8 figures, 12 tables and 1 endnote.)