How do I interpret intervention lines on a student graph?

The easyCBM system was developed to support teachers using a Response to Intervention approach to meeting student needs.

The intervention lines, which will always display on the Individual graphs, are an important part of interpreting the information those graphs display. The way the interpretation works is that you look for an improvement (high scores, and/or steeper rate of improvement) after an intervention than before an intervention, and that improvement helps you decide the degree to which the intervention is working. In other words, you look for a ‘response’ to the ‘intervention’, with the ‘response' graphically displayed by the line showing student progress over time, and the ‘intervention’ graphically displayed by the vertical intervention lines on the graph.