The social support literature lacks empirical studies addressing structural distinctions between social network ties. It often divides social support into functional categories such as material, emotional, or advice support, with little regard to specific support providers or how the support from these providers can be delineated by individuals receiving support. In this study, 125 undergraduate students used a 7-point Likert-type scale to rate how similar support providers were to each other in how they were supportive. The data were analyzed using multidimensional scaling analysis. Subjects also rated each support provider on 17 adjectives (e.g. warm, accessible, equal), and these ratings were regressed over the two principal dimensions and helped define them as "intimacy" and"equality/relevance to daily life." The "intimacy" dimension primarily separated informal providers such as family and friends from providers whose interactions are more likely to be structured and organized, such as school and work personnel. The second dimension seemed to separate providers more or less likely to be involved in daily interactions with the participant, whether or not these interactions were intimate. Friends, bosses, schoolmates, and faculty were high on this dimension, while kin and doctor/dentist were low. Cluster analysis of the similarities ratings and factor analysis of the adjective ratings corroborated these results. (Author/NB)