Assessment and Eligibility
Domain 3: Assessment and Eligibility
This domain tests the evaluation process, measurement concepts, and legal decision points. You need to interpret scores, select appropriate assessments, and explain how teams determine eligibility and write IEPs.
Core rules
- Pre-referral systems such as RTI or MTSS use universal screening, tiered intervention, and progress monitoring. RTI data can support eligibility but cannot be the only criterion.
- Norm-referenced tests compare a student with peers; curriculum-based measurement (CBM) tracks growth against goals. Standard scores have a mean of 100 and a standard deviation of 15, so 85 is one standard deviation below the mean, near the 16th percentile.
- Reliability concerns consistency; validity concerns whether a test measures what it claims. The standard error of measurement creates a confidence band around a score.
- A comprehensive evaluation uses multiple sources, is conducted in the student's native language when feasible, and rules out exclusionary factors. No single measure can determine eligibility.
- IDEA requires informed parental consent before initial evaluation, a timeline for completion (often 60 days, with state exceptions), and reevaluation at least every three years unless waived.
Worked example
A student earns a standard score of 85 in reading. The team should not declare SLD from that score alone. The score falls in the below-average range, but the confidence interval may overlap the average range, and the team must examine classroom data, intervention response, and exclusionary factors. If CBM shows flat growth despite faithful Tier 2 intervention and processing deficits are documented, the pattern is stronger.
Traps that cost marks
Do not equate a single low score with a disability. Do not ignore the standard error of measurement. Do not treat RTI as a legal mandate or as sufficient by itself. Do not skip consent, native-language considerations, or the three-year reevaluation rule.