At the end of every MAP Growth test event, an automatic data quality control process determines if a test score should be considered untrustworthy. Currently such factors as too short of a test duration, too high SEM, and other factors will cause a test event to be invalidated. Beginning July 21, 2018 test events in which 30% or more of the items received rapid guesses will be flagged as invalid. Unlike test duration, which is generic across all items, rapid-guessing detection is based on the amount of time required to read, understand, and answer each unique item. You can find out more about student testing engagement and rapid-guessing here.