The continual movement from node to node therefore creates an underlying rhythm, reinforced by the physical movement of a mouse button or key and its audible click. Individual nodes may also combine to form compound rhythmic units, or periods. Any succession of nodes that cohere as a group because of their content or appearance and seem distinct from surrounding nodes is likely to be perceived as a rhythmic period. Several periods can combine to form larger ones, and periods can overlap. The distinctness with which hypertextual rhythmic units are articulated depends primarily on the degree of disjunction that the content of a node or period has from the material preceding and following it and the degree of closure with which it ends.
Navigational elements can also affect articulation, though.
A sudden increase in the number of available links or in the complexity of interactive options can create a structurally significant break in the reading as the reader ponders what to do next. The length of rhythmic units has a marked effect on hypertextual rhythm. Conversely, though, the reader may perceive a decrease in node length as a slowing down. The greater frequency of breaks between nodes introduces pauses between passages that could otherwise have been presented as uninterrupted text in a single node. The sense of tempo therefore depends upon the content of the nodes as well as their length.