ABA Exam Coach

C.5: Distinguish between continuous and discontinuous measurement procedures.

Free practice questions for this part of the BCBA, with an explanation for every option.

Which of the following is a continuous measurement procedure?
  1. A. Momentary time sampling every 2 minutes
    Incorrect. MTS samples behavior only at set moments and misses everything between them.
  2. B. Whole-interval recording with 15-s intervals
    Incorrect. Whole-interval recording gives an estimate based on intervals, not a record of every instance.
  3. C. Partial-interval recording with 10-s intervals
    Incorrect. Partial-interval scores an interval once no matter how many responses occur, so it does not capture every instance.
  4. D. Event recording of every instance of hand-raising during a class period
    Correct. Continuous measurement detects every instance of the behavior during the observation period, which event recording of each hand-raise does.
A colleague says that partial-interval recording is a continuous measure because the observer watches the whole time. What is the best response?
  1. A. Partial-interval is discontinuous because it does not capture every instance or the actual duration of behavior. Several responses in one interval are scored as a single occurrence.
    Correct. Interval methods record whether behavior occurred in an interval, not each instance or its exact duration, so they are discontinuous.
  2. B. Partial-interval is discontinuous only when intervals are longer than 30 seconds.
    Incorrect. Interval length affects how accurate the estimate is, not whether the procedure is continuous.
  3. C. The colleague is correct, because any procedure with uninterrupted observation is continuous.
    Incorrect. What makes a measure continuous is whether every instance is detected and recorded, not whether the observer is watching.
  4. D. Partial-interval is continuous because it overestimates behavior instead of underestimating it.
    Incorrect. The direction of error has nothing to do with whether a procedure is continuous. Systematic error is in fact a feature of discontinuous methods.
A BCBA has to decide whether a new measure of a client's head-rocking needs to capture actual duration or can rely on an estimate. Which situation most clearly calls for a continuous measure rather than a discontinuous one?
  1. A. The research question is whether a medication change shortens each head-rocking bout by about 10 seconds.
    Correct. Detecting small changes in duration per occurrence needs precise timing of each bout's onset and offset, which discontinuous methods cannot give.
  2. B. Staff are monitoring 8 students at once and can only glance up periodically.
    Incorrect. Limited observer availability is a reason to choose a discontinuous procedure such as MTS.
  3. C. Head-rocking occurs for most of each session, and the team only needs a rough estimate of how much it changes over months.
    Incorrect. A rough estimate of a high-rate or long-lasting behavior can be gotten efficiently with time sampling.
  4. D. The behavior has no clear onset or offset, so counting individual instances is not possible.
    Incorrect. When onsets and offsets are unclear, interval or time-sampling methods are often more practical than continuous counts.

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