The item mean for the five perception of expertise items (Table I) was 1.526 with variance of .004. This mean was significantly higher (t286 = 29 .27,p < 0.001) than the midpoint of the scale (0 - Both Equally). The effect size, Cohen’s d was 1.72, indicating a large effect. Figure 3 shows that for the five perception of expertise scale items, most of the respondents (approximately 70% to 80%) thought they had a better perception of the expertise of their code review partners than their non-code review partners.