Most of the organizational phenomena are hierarchically imbedded, easily making research data clustered in nature. Data analysis without considering non-independence often leads to misunderstanding of the phenomenon under examination. Based on extant literature, this study first addressed the level issues from an ontological perspective, followed by a discussion of methodological concerns of nested data. As an illustration, a set of data investigating the effects of paternalistic leadership and the moderation of group cohesiveness was analyzed with OLS and RCM techniques. The impacts of data non-independence were illuminated through comparing the results from single level (i.e., both individual and group) and cross level analyses. The relationships between constructs were largely inflated in single level analyses. Implications of analyzing nested data were addressed.