What is the difference between disaggregation of data and aggregated data in progress monitoring?

• A. Aggregated data show overall progress.
• B. Disaggregation reports outcomes by subgroup (e.g., by disability) to identify gaps.
• C. Disaggregation hides subgroup differences.
• D. Disaggregation is used only for compliance reporting.

Answer: (B)

In progress monitoring, aggregated data give you the big picture by combining everyone's results to show overall progress. But that can hide important differences between subgroups. Disaggregation, on the other hand, separates the data into subgroups (for example, by disability status) so you can see how each group is actually progressing. This is crucial because it reveals gaps—like one subgroup making steady gains while another lags behind—so you can tailor supports and interventions where they’re most needed.

So the best description is that disaggregation reports outcomes by subgroup to identify gaps. While aggregated data can illustrate overall trends, it doesn’t show where disparities exist. Disaggregation makes those differences visible and actionable, and it’s not limited to compliance purposes but is a practical tool for ensuring all students make progress.