This document outlines a research study on the impact of diagnostic tests in enhancing students' learning. It discusses how diagnostic tests can identify students' strengths and weaknesses in order to provide targeted support. The study aims to examine student performance, evaluate new data compared to previous results, and investigate the positive effects of diagnostic testing on learning. Key points include that diagnostic tests assess students' prior knowledge before instruction, allow teachers to individualize lessons, and create a baseline for measuring future learning. The characteristics, process, and theoretical framework involving diagnostic tests are also reviewed.