A study by Stipek and Ryan (1997) is also especially relevant to this report, mostly in terms of the first two of the three similarities shared with the Phillips et al. (1998) study. A difference from the study by Phillips and colleagues is that the Stipek and Ryan study focused on the social background factor of SES instead of race. However, besides examining cognitive performance as children begin kindergarten, these researchers explored such outcomes as performance gain, self-confidence, attitudes toward school, expectations for success, and preference for challenge. Although economically disadvantaged children scored lower on initial cognitive performance, SES-related differences remained steady over the first two years of school. Moreover, there were few differences related to disadvantage on other outcomes.