TTL-MSM (Testing-the-Limits with Multi-Source Model): Documentation Suite, Version 2.0

TTL-MSM (Testing-the-Limits with Multi-Source Model) is an educational decision-making framework for school-based speech-language assessment. Methodologically, it functions as a clinical decision rule: clinician-supplied evidence is combined through a fixed convergence criterion. It determines whether a student's communication profile is more consistent with a speech-language disorder or with linguistic, cultural, instructional, or exposure-related difference — the disorder-versus-difference classification at the center of an IDEA eligibility evaluation for speech or language impairment. Unlike clinical diagnostic systems, TTL-MSM classifies at the educational construct rather than clinical etiology. Expert-supplied inputs — standardized measures, dynamic assessment of modifiability, language sampling, classroom observation, and parent and teacher report — are each coded once and combined by a fixed convergence criterion. The design follows the actuarial tradition in clinical judgment research: the advantage of mechanical combination lies in consistency, not in optimally weighted parameters. The framework is designed for complex case assessment — evaluations in which the evidence is conflicting, incomplete, or ambiguous. Culturally and linguistically diverse and multilingual profiles are the sharpest instance of this, not its boundary; the same structure is designed to address profiles such as high-masking autism, traumatic brain injury, twice-exceptional presentations, and other cases in which a single-layer clinical read may misrepresent the educational question. TTL-MSM's scope is domain-general across language, articulation, and fluency. This deposit contains the five-volume v2.0 documentation suite: • V1 · Overview — front-door introduction and routing • V2 · Framework Specification — what the framework is and how it is administered • V3 · Evidence Base & Validation Status — component evidence, theoretical foundation, validation pathway • V4 · Implementation Guide — design rationale and implementation science • V5 · Appendices — glossary, fidelity checklist, references, disclosures, version history Validation status: derivation complete; developmental evaluation and preliminary developmental evidence in hand; formal internal validation pending; external validation pending; impact analysis future. On the clinical decision rule development pathway, this deposit represents the derivation stage. The integrated framework has not been validated through prospective or independent research. Claims throughout the suite are tagged with explicit evidence grades. Licensed CC BY 4.0. "TTL-MSM" is a trademark of the author; federal registration pending.