What does the antecedent in a tact contingency involve?

In a tact contingency, the antecedent typically involves a stimulus that can be seen, heard, or otherwise perceived, which provokes a verbal response that labels or describes that stimulus. This process involves the speaker observing something in their environment, which then leads to the verbal operant known as a tact.

Seeing "Mama" exemplifies this as it represents a situation where the child perceives a person and then may verbally label or refer to her, thereby fulfilling the requirement of a tact. The primary aspect of a tact is that it is a non-verbal stimulus prompting a verbal response that serves to identify or describe what is being observed.

Other options, such as desiring an object or requesting help, are related to different types of verbal operants, like mands. A mand is driven by a need or desire, and requesting help goes beyond mere observation. Describing an action also falls under different verbal operants that may not emerge directly from an antecedent stimulus requiring mere observation.