dentify the appropriate antecedent variable (MO or SD) described in the following examples.

Timmy's favorite snack is Doritos chips. He has not had these since yesterday and is just arriving home from school, which usually means he gets a snack. Timmy walks in and doesn't see his mom, so he begins looking through the cupboards for a snack. Timmy opens one cupboard and sees a bag of Doritos on the top shelf. Timmy moves a chair over to the cupboard and stands on it to get the chips. He then sits at the table and enjoys his favorite snack. In the above example Timmy moving the chair and standing on it was the BEHAVIOR and eating the chips was the CONSEQUENCE. Timmy seeing the chips on the top shelf is the _____ in this scenario.

Timmy's favorite snack is Doritos chips. He has not had these since yesterday and is just arriving home from school, which usually means he gets a snack. BUT TODAY Timmy's class at school had a birthday party for one of his classmates during the last 30 minutes of class, and Timmy ate a piece of pizza and a cupcake before arriving home. Timmy walks into his house after school and Timmy's mom is putting some groceries away in the cupboard, including a bag of Doritos. Timmy sees his mom place the Doritos on the top shelf and then asks his mom if he can have a glass of milk. In the above scenario, Timmy having eating pizza and a cupcake prior to arriving home is the ________ for asking for chips. (Hint: Timmy just ate a lot of food; therefore, the reinforcing value of the chips has decreased, and he is less likely to engage in behavior that has resulted in access to chips in the past, such as moving a chair to reach them or asking his mom for them.)

Same scenario: Timmy's favorite snack is Doritos chips. He has not had these since yesterday and is just arriving home from school, which usually means he gets a snack. Timmy walks in and doesn't see his mom, so he begins looking through the cupboards for a snack. Timmy opens one cupboard and sees a bag of Doritos on the top shelf. Timmy moves a chair over to the cupboard and stands on it to get the chips. He then sits at the table and enjoys his favorite snack. In the above scenario, Timmy having arrived home from school, which is usually snack time, and not having eaten his favorite snack since yesterday is the _____ for Timmy engaging in behavior such as looking for his mom, then looking through the cupboards, and finally moving a chair to access the Doritos from the top shelf.