Use of a paired‐stimulus demand analysis to evaluate demands for inclusion in functional analyses

Zangrillo et al. (2020) ran a five-minute paired-stimulus demand test before each FA. They showed two demands side by side and noted which one the child reached for first.

The team then used the least-chosen demands in the FA escape condition. They wanted to see if this small tweak would catch escape functions that the usual, most-chosen demands might miss.

The least-selected demands always triggered more problem behavior. They found a clear escape function for every participant.

The most-selected demands missed the escape function in three of four kids. Picking the right demands mattered more than anyone expected.

Griffith et al. (2021) also trimmed FA time by showing that five-minute sessions work as well as ten-minute ones. Together, the two papers give you a faster, clearer FA: pick short sessions and the hardest demands.

Nevin et al. (2005) warned that combined antecedents can reveal hidden functions. Zangrillo's method does the same thing in a simpler way: it pre-screens demands so you do not need extra antecedent layers.

Geckeler et al. (2000) used paired choices to find reinforcers. Zangrillo flips the idea to find aversive tasks. Same logic, opposite goal.

Next time you plan an FA, spend five minutes on a paired demand test. Use the tasks the child avoids most in your escape condition. You will cut false negatives and finish the whole assessment faster.