Designed/Targeted intervention has been implemented. Length of phase, how long intervention will last, is determined by the RTI team using ongoing data collected.
Strategic progress monitoring - checking to see if the intervention is working to remediate the student's specific misunderstanding or lack of skill. Five to six valid measurements over 4-6 weeks verifies that learning has been successful. The intervention is adjusted (made more intensive) if it is ineffective after 3-4 valid measurements have been taken.