Research foundation

The research finding

Per-domain adaptive testing places students faster and more accurately than fixed-form tests, especially at the tails of the distribution. Content blueprinting ensures balanced coverage across substandards.

How we apply it

Math assessment routes 4 domains independently through graduated difficulty phases (4 strata from easy to hard), with substandard round-robin ensuring every content area is sampled. SEM-based early stopping ends testing when measurement confidence is high enough. Confidence-weighted compositing means domains measured more precisely count more in final placement. Rapid-guess filtering excludes suspiciously fast correct answers (<2s). Anchor items link test forms across windows for future IRT calibration. Aligned to Babcock & Weiss (2012) CAT stopping rules, Haberman (2008) Laplace-smoothed scoring, and Kingsbury & Zara (1989) content balancing.

Citations

The research finding

Explicit instruction across the National Reading Panel's Big Five (phonemic awareness, phonics, fluency, vocabulary, comprehension) produces the strongest reading outcomes.

How we apply it

Reading assessment tests 16 skill areas across the Big Five. Per-skill proficiency is reported separately, so teachers can target interventions rather than relying on a single composite score. Passages are calibrated to F&P A-Z, Lexile, DRA, and Grade Equivalent.

Citations

The research finding

Math concepts are learned most durably when students move from physical/visual models to representations to symbolic abstraction.

How we apply it

K-8 tiers use concrete manipulatives (ten frames, base-10 blocks, fraction bars, coins, tape diagrams) before introducing symbolic forms. A dedicated Tools shelf gives students 20+ interactive manipulatives — including algebra tiles, pattern blocks, geoboards, protractors, and array builders — available for free exploration alongside guided practice. Tier labels indicate the CRA stage so teachers can sequence instruction.

Citations

The research finding

Expanding review intervals produce 2–3× retention compared to massed practice, with the biggest gains for long-term recall.

How we apply it

Our review queue derives SM-2 ease factors from each student's score history. Intervals start at 1 day, expand to 6 days, then scale by ease factor — capped at 60 days. A 15% trajectory bonus extends intervals when recent scores improve.

Citations

The research finding

Students who believe ability is malleable and receive process-focused feedback outperform matched peers on transfer tasks. A try-first approach where wrong answers unlock hints rather than immediate penalties builds persistence.

How we apply it

Feedback language is process-focused ('Your strategy paid off') rather than trait-focused ('You're smart'). First wrong answers unlock a hint bulb instead of penalizing — students choose when to use hints, building self-regulation. Spaced review resurfaces past mistakes for retrieval practice.

Citations

The research finding

Reading comprehension is best measured with passage-based testlets that adapt at the passage level, not individual items. Passages must meet research-calibrated length and complexity standards, with text-dependent questions spanning multiple Depth of Knowledge levels.

How we apply it

Assessment passages are calibrated to Smarter Balanced word-count ranges by grade (G3: 300-450 words, G6: 650-850, G9-12: 800-1200). Each passage has 12-16 authored questions; the system selects 6-8 per sitting stratified by skill type — giving two equivalent test forms per passage and doubling the effective item pool. Passages are tagged by within-grade difficulty (below/at/above) for adaptive routing: easier passages in early phases, harder in escalation phases. Questions are tagged by DOK level (20% recall, 55% inference, 25% analysis) and by reading skill. Anchor items link test forms across testing windows for longitudinal calibration. Every question must fail the text-dependence test: if a student can answer without the passage, the question is rewritten.

Citations

The research finding

Multiple-choice items with diagnostic distractors — wrong answers that target specific misconceptions — yield richer information than items with merely plausible options. Three well-designed options are psychometrically equivalent to four or five.

How we apply it

Every wrong answer targets a documented error pattern: wrong-paragraph confusion, partial comprehension, background-knowledge substitution, or overgeneralization. Items follow Haladyna, Downing & Rodriguez (2002) validated taxonomy of 31 item-writing guidelines, including stem clarity, option homogeneity, and randomized correct-answer position.

Citations

The research finding

Students who attempt problems before receiving instruction outperform those taught first — but only when scaffolded feedback follows the struggle. Assessment must remain unscaffolded to preserve measurement validity.

How we apply it

Practice uses a try-first hint system: first wrong answer triggers a retry (no penalty), second wrong unlocks progressive hints, with the full explanation on the final step. Assessment passages provide no hints, no vocabulary definitions, and no corrective feedback — measuring what students know independently. This dual approach follows Shute (2008) and Kapur (2016).

Citations

The research finding

Students who answer too quickly exhibit a distinct response pattern that, when flagged, allows teachers to re-administer items and improve validity. Reading items require longer thresholds than math because of passage processing time.

How we apply it

Math items use grade-adjusted thresholds (K-2: 4s, 3-5: 3.5s, 6-8: 3s, 9-12: 2.5s). Reading items use a passage-aware formula: base threshold plus passage word count divided by grade-appropriate reading speed. Students flagged at >30% overall or >40% per skill get a rushed indicator in the teacher dashboard.

Citations

The research finding

External rewards that feed into student identity (collections, customization) build voluntary practice habits that persist after rewards are removed.

How we apply it

Cosmetic items, companion customization, and pet adoption are the primary reward loop. Stars earned through practice are the only currency. No pay-to-win advantages exist.

Citations