Everyday, I help break down a confusing ABA term and put it in plain English! Whether you are studying for your BCBA exam, explaining ABA to parents or are a student, there is no reason to be so confused over ABA terms. While “behavioral language” is very confusing, these concepts don’t have to be.

According to Cooper, Heron and Heward, planned activity check (PLACHECK) is “A variation of momentary time sampling in which the observer records whether each person in a group is engaged in the target behavior at specific points in time; provides a measure of “group behavior.””

Simply put, PLACHECK is when you use momentary time sampling with a group. Momentary time sampling is when you set a timer and when the timer goes off, record whether or not a person is engaged in a behavior. With PLACHECK, you set a timer and when the timer goes off, record how many people are engaged in a behavior. This is very useful in a school or group setting when there is not a lot of resources towards taking data but you require data to make a decision. Like momentary time sampling, PLACHECK tends to neither overestimate or underestimate occurrences of a behavior. It is also important to note that PLACHECK records individual behavior within a group that in applied behavior analysis, there is an underlying belief that individuals and not groups behave.

For example, a teacher wants to track on-task activity during an independent work session. She divided a 60 minute class period into 6 ten minute intervals. She sets a timer. Everytime the timer goes off, she writes down how many of the students in her class are completing worksheets.


Cooper, J. O., Heron, T. E., & Heward, W. L. (2019). Applied Behavior Analysis (3rd Edition). Hoboken, NJ: Pearson Education.