Although low participation rates have historically been considered problematic in peer nomination research, some researchers have recently argued that small proportions of participants can, in fact, provide adequate sociometric data. The current study used a classical measurement perspective to investigate the internal reliability (Cronbach's alpha) of peer nomination measures of acceptance, popularity, friendship, prosocial behavior, and overt aggression. Data from 642 participants attending 10 schools were resampled at different participation rates ranging from 5 percent to 100 percent of the original samples. Results indicated that (1) the association between participation rate and Cronbach's alpha was curvilinear across schools and variables; (2) collecting more data for a given variable (by using unlimited vs. limited nominations, or two vs. one items) was significantly related to higher internal reliability; and (3) certain variables (overt aggression, popularity) were more reliable than others (acceptance, friendship). Implications for future research were discussed. (Contains 1 figure and 4 notes)