Percent correct is the unit of analysis that is most commonly used in traditional education. However, it is not clear as to why 100% accuracy the only criterion. Does a student automatically have full mastery of the material the first time they achieve 100% accuracy? Not necessarily.
I believe I have given this example before, but I’ll give it again since it is a good one. Bobby and Sally take the same test. The two students both obtain 100% accuracy on the test. However, Bobby takes 15 min while Sally takes 1 hour. A percent correct measure does not capture the difference between these two learners.
Performance on a test or on any academic target is a behavior. All behavior occurs in time. However, when one takes time out of the equation, it only gives a fraction of a description of what is actually occurring (i.e., how this student performs or learns). Proficiency of a particular skill cannot be simply measured by percent correct measures alone.
Today, I just had an assessment meeting with a parent of a 5th grade boy. His mom reported that the school indicated that he was performing at grade level for math. However, my assessment indicates that he is performing at the end of 2nd grade for math. The difference between the two assessments is that the only criterion for the school is a percent correct measure. The student is highly accurate, but is very slow and reliant on aids that serve as crutches. He has relied on these crutches for so long, they will never fade out unless they are specifically targeted. Although he is surviving in the classroom right now, this does not mean he will be able to get by with these aids in the future. Relying on such aids and not being fluent at a skill independently yield significant problems in more advanced classes (e.g., writing, algebra). This student will be spending more time with these aids for foundational skills than comprehending new and more complex material.
If you really want to capture how well your child is performing on a particular task, you need to include time, count, and accuracy. These three units, when combined in a particular way, give a true definition of fluent performance. In other words, you want n amount of responses (e.g., problems, answers, words) in x amount of time with 100% accuracy. When you see the same amount of responses occurring in a less amount of time while maintaining 100% accuracy, you are seeing more proficient performance. Another way to view this relationship is when more responses are occurring for the same amount of time while maintaining 100% accuracy.
Therefore, learning does not stop at 100% accuracy, and doing so is rather limiting the student. Accuracy is the first step. However, working on speed is the second step. Once performance is similar to that of someone who is considered proficient (e.g., a parent or teacher) with respect to count and speed, the skill is more likely mastered than when it was just occurring at 100% accuracy. If you require more, you will get more. Challenge your student to go beyond 100% and they will thank you for it in the long run.