Michael (1985) distinguished between two kinds of verbal behavior which he identified as selection-based (SB) and topography-based (TB). Research has shown substantial differences between the two types of verbal behavior for nonverbal participants, but little differences has been found with highly verbal participants. This study arranged for highly verbal participants (college students) to engage in a SB task while "talking aloud," one of Ericsson & Simon's (1993) techniques for conducting protocol analyses. The transcripts of these sessions were analyzed in terms of Skinner's (1957) elementary verbal operants. Very consistent types of statements were found to precede correct selections in the SB task. This finding lends support to the possibility that some SB conditional discriminations, and related emergent equivalence relations, are mediated by TB vocal responding when using highly verbal participants. These data also account for some of the differences observed in the SB and TB research.Two different types of verbal behavior have been identified by Michael (1985) as selection-based (SB) and topography-based (TB). Selection-based verbal behavior consists in pointing toward, touching, or in some way identifying a verbal stimulus, for example a symbol or picture on a communication board (McDonald & Schultz, 1973), or selecting a picture card from a stack as is used in the Picture-exchange communication system (Bondy & Frost, 1993 research with apes (Savage-Rumbaugh, 1984) and is currently used extensively as a form of augmentative communication for developmentally disabled individuals with very defective vocal behavior (Shafer, 1993). A developmentally disabled child naming something (a tact) or requesting something (a mand) by pointing to the appropriate symbol on her communication board is an example of SB verbal behavior.In SB verbal behavior, the stimulus and response each involve two components. The stimulus involves (1) a sample stimulus or establishing operation (the mand), that affects the responder in such a way as to (2) increase the evocative control of one of the choice stimuli over the pointing or indicating response. Such a situation is often called a conditional discrimination (Sidman, 1994): the stimulus pointed to is conditional upon what is being named or asked for. The response in SB verbal behavior involves (1) scanning the stimulus array, then (2) emitting the pointing response to the appropriate choice stimulus.41