In the effort to assess student ability performance factors are likely present. It is incumbent upon the educators to mitigate the performance issues to assess true ability.
For example, I conducted an evaluation on a student in middle school who has ADHD. All of her testing records indicated that she would lose focus during the assessment and that the focus was problematic for testing. Before we met I surveyed her on her favorite snack (didn’t know Sour Skittles is a thing), brought this reinforcer along with a bottle of water. She sat through an entire 1 1/2 hour KeyMath Assessment without incident.