Process control
Overlaps can often be seen as problematic in terms of turn-taking, with the majority of research being between cooperative versus competitive overlap. One theory by Goldberg (1990) argues the dynamic relationship between overlap and power over the conversation by suggesting that two types of overlap are power interruptions and displays of rapport. During conversation, a listener has an obligation to support the speaker. An interruption impedes upon this obligation by infringing upon the wishes of the speaker (which is to be heard). The difference between a power interruption or rapport is the degree to which the speakers' wishes are impeded upon. Rapport interruptions contribute to the conversation in that they ultimately cooperate and collaborate with the speaker in order to reach a mutual goal of understanding. Power interruptions are generally hostile and do not cooperate with the speaker. The goals of the power interruptor are both divergent from and regardless of the goals of the speaker. Power interruptions are further categorized into two types: process control interruptions and content control interruptions. Process control interruptions involve attempts to change the topic by utilizing questions and requests, and because they return control to the original speaker are generally seen as the less threatening of the two. Content control interruptions involve attempts to change the topic by utilizing assertions or statements that are unrelated to the current topic. Content control interruptions are viewed as problematic and threatening since they seize control of both the topic and attention away from the speaker.