Independent sample t-tests of mean differences (equal variances not assumed) indicated that full-time respondents scored higher than part-time (less than full-time) respondents on several items contributing to this benchmark: (1) number of written papers/reports of 5 to 19 pages, (2) number of written papers/reports fewer than 5 pages, (3) number of assigned books read, and (4) time spent preparing for class. These advantages accruing to full-time respondents extended to both first-year students and seniors. As compared to part-time students, full-time students did not report that they wrote a greater number of papers/reports of 20 pages or more.

Overall, part-time students did not constitute large percentages of undergraduate enrollments at 2000-02 institutions, particularly for first-year students (mean=10.0 percent, standard deviation=12.3 for first-year students, mean=22.1 percent, standard deviation=16.6 for seniors)1. However, there are a small number of institutions with much higher percentages of part-time students. For example, part-time students comprised greater than 40% of first-year students at 18 institutions, and more than 50% of seniors at 42 institutions. Given the t-test results, institutions with more part-		 time students will tend to score lower on the four items analyzed earlier (READASGN, WRITEMID, WRITESML, and ACADPR01). To compensate, we adjusted the responses of part-time students at each school to resemble those of full-time students on each of these items.

To compute part-time adjustments, we first calculated mean item scores for each institution by class and enrollment status for each item. We then divided the institutional mean for full-time students on the item by the institutional mean for part-time students on the item among first-year students. If the ratio was greater than unity, it meant that full-time (first-year) students scored higher than part-time (first-year) students at this institution, on average. The item responses of part-time (first-year) students at this institution were then multiplied by this ratio greater than unity. The same procedure was applied to seniors. If, for a particular student, the resulting product was greater than the maximum possible score on that item, the student’s score was capped at the maximum. In contrast, if the ratio was less than unity, no adjustment was applied to part-time responses at this institution for this item.

1From 1997-2000 IPEDS data