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 2001-2003
institutions, particularly for first-year students (mean=5.0 percent, standard deviation=9 for
first-year students, mean=16 percent, standard deviation=13 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 11 institutions, and more than 50% of seniors at 47
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.
1 From 1998-2000 IPEDS data
