Abstract : Tangible user interfaces and physical representations of data are both promising approaches to improving insights derived from large data sets. Interactive tangible representations of data, which seamlessly combine those two approaches, potentially take advantage of cognitive processes, data representations, and interactions not supported by current approaches and may enhance collaboration. This paper describes user evaluations of two sets of prototypes comprised of physical blocks to represent data. One set uses six blocks of identical dimensions and another set uses six blocks with different dimensions. The objectives of this pilot study include (i) making general observations on how users interact with the two prototypes, (ii) making observations on the role these tangible interfaces play in collaboration, and (iii) comparing the two sets of tangible interfaces. We report on the results of the study and discuss future work. make general observations on how users interacted with the tangible interfaces; two, to make observations on the role the tangible interfaces play in collaboration; and three, to compare the two sets of tangible interfaces with one another. We report on the results of the study and discuss future work.