Diagnostic assessment is evaluation designed to identify specific learning gaps, strengths, and needs. Unlike assessments that measure overall achievement, diagnostic tests pinpoint particular skills or concepts students have or have not mastered, guiding targeted instruction and intervention.
When Diagnostics Are Used
Teachers use diagnostic assessments at the start of instruction, when students struggle, before intervention placement, and to understand why students aren't progressing. Results help educators target specific skills rather than reteaching broadly.
Examples
Diagnostic tools include reading inventories that identify decoding vs. comprehension issues, math diagnostics pinpointing specific skill gaps, and special education evaluations identifying processing weaknesses.