Effect size, which helps determine the extent to which statistically
significant changes are likely to be meaningful, was
also calculated (Cohen, 1992). Consistently, Cohen’s d measurements
revealed that the Science Skills treatment for group
2 had a modest effect size midyear (d = 0.57). By the end of
the year, when both groups had received the treatment, an
even larger effect size was seen (d = 1.0 and d = 0.70, respectively;
see Table 2B). Similar patterns were seen from analysis
of question 5 responses, in which students clearly identified
science skills when describing their own particular strengths
in science, confirming the results obtained with question 2
(unpublished data).