Previous studies have identified two sets of key attributes for information sources that influence employees' information-seeking behavior: (a) the characteristics of sources, including quality and accessibility, and (b) the types of sources, including those identified as relational and non-relational. However, little is known about what causes employees to make choices based on either the characteristics or types of sources, as distinguished above. This study proposes to use the sufficiency principle to explore the motivational mechanisms that underlie information source selection. Using data collected from 165 Extension (CCE) educators, the proposed hypotheses were tested using a hierarchical linear modeling approach. The results suggest that information insufficiency is the key determinant which moderates employees' choices between the characteristics and types of sources.