This document discusses diagnostic evaluation tests which are used to assess students' strengths, weaknesses, and skills prior to instruction. It allows teachers to diagnose student difficulties and guide lesson planning. The tests can identify slow and advanced learners. Teachers can then provide remediation for slow learners or enrichment activities for advanced learners. The purpose is to create a baseline and design instruction that meets each student's needs. An example is provided of a study that used diagnostic tests and found students taught with information and communication technology performed better than those taught without it.