Haptic-audio interfaces allow haptic exploration of statistical line graphs accompanied by sound or speech, thus providing access to exploration by visually impaired people. Verbally assisted haptic graph exploration can be seen as a task-oriented collaborative activity between two partners, a haptic explorer and an observing assistant, who are disposed to individual preferences for using reference frames. The experimental findings reveal that haptic explorers' spatial reference frames are mostly induced by hand movements, leading to action perspective instead of conventionally left-to-right spatiotemporal perspective. Moreover, the communicational goal may result in a switch in perspective.