What are the differences between practice tests and diagnostic tests for standardized test prep? First, a diagnostic test should provide you, the parent, with insight about the skills of your child. A diagnostic test can appear in the same form or can be shorter in length. Most importantly, make sure the person administering the test and the test itself are valid for helping you decide when and how to prepare. Many parents are happy to realize, when meeting with Novella Prep, that much can be done within the school and with existing teachers to make the most of their son or daughter’s schooling. With that foundation, additional skills can be taught through tutoring or test prep. Practice tests, on the other hand, are helpful to acclimate students to the duration and format of the test. But, just like checking the weather 5 times within one minute, measuring and measuring is not the key to success: skill mastery, is. Check out our Novella Prep PSAT Diagnostic, a free tool to help students and their parents understand how to make the most of their schooling and prepare for important standardized tests. Take the Novella Prep PSAT diagnostic test.