Why do some explanations to Questions take longer than others?

In order to ensure that students always receive the highest-quality help from tutors, we’ve implemented a quality assurance step in the tutoring process. This step serves to ensure that all submitted Questions go through a standard quality check to make sure they’re ready to receive high-quality explanations from tutors. With this quality check, a single Question can be sent back to students for revision up to 3 times. Although this back-and-forth may increase response times from tutors, it also increases the likelihood that the Question is clearly understood by tutors, thereby allowing students to receive the most helpful and highest-quality explanations possible.