Which term refers to the initial data collected before starting intervention to establish starting performance levels?

• A. Baseline
• B. Assessment of effectiveness
• C. Description of target response
• D. Modification plan

Answer: (A)

Baseline data are the initial measurements collected before any intervention is started, serving as the starting point to establish how the learner is performing. This pre-intervention data show the current level of the target behavior and provide a reference for measuring progress and setting goals. By gathering several initial data points, you get a stable snapshot rather than relying on a single observation, which helps determine what needs to change and how much progress counts as success.

The other options describe different ideas: assessing effectiveness refers to evaluating outcomes after intervention to see if changes occurred, not the starting point; a description of the target response is about what behavior you’re measuring, not the baseline measurement; and a modification plan outlines how you'll adjust the intervention, which happens after data are collected and analyzed.