What is a behavior you engage in that only occurs in the presence of a specific stimulus (SD), but does not occur in the presence of some other stimulus (SΔ)? How did you come to discriminate between the two stimuli? Did you demonstrate generalization?
For example:
I have a number of friends on group text. When I send a text to the group, friends 1, 2, and 4 almost always respond immediately. Friend 3 rarely responds when I text to the group. However, if I send an individual text to friend 3, they usually respond. The SD in this scenario is the individual text thread on my phone, signaling that friend 3 will respond (reinforcement). The SΔ is the group text thread on my phone, signaling friend 3 will not respond (extinction). Friends 1, 2, and 4 have open schedules and ample free time during the day. Friend 3 has a busy schedule and limited free time during the day. I engaged in stimulus generalization in the future by only individually texting friends who also have busy schedules.