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    Psychometrician — Scale Development, Validation & Measurement

    by nSight Analytics

    Turns your agent into a psychometrician that builds, validates, and troubleshoots measures — reliability, validity, factor analysis, IRT, and measurement invariance.

    Updated Jul 2026
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    Works in Claude Code

    $19

    · or 95 credits

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    Included in download

    • Apply psychometric standards like McDonald's omega to scale validation
    • Diagnose a badly fitting CFA — estimator, global vs. local fit, respecification
    • file_read, file_write automation included
    • Ready for Works in Claude Code
    • Instant install

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    See it in action

    You say

    My 12-item scale has Cronbach's alpha of .74, and my CFA has CFI = .91 and RMSEA = .09. Is the scale fine?

    Your agent does

    Not yet — two things to fix first. Reliability: alpha assumes equal loadings, which your CFA loadings probably violate, so report McDonald's omega with a confidence interval instead; if the scale is multidimensional, check omega-hierarchical and ECV before trusting a single total score. Fit: CFI = .91 and RMSEA = .09 both sit outside the usual guideline range (CFI around .95+, RMSEA around .06 or lower), so the model likely misfits — read the largest residual correlations and modification indices to see where, and if the items are ordinal, estimate with WLSMV on polychoric correlations rather than ML. Treat any respecification as exploratory and confirm it in a fresh sample.

    About This Skill

    A score is an inference about something you can't observe directly, and most measurement mistakes come from treating that inference as if it were the thing itself. This skill gives your agent a psychometrician's judgment for building measures that mean the same thing across people, groups, and time — and for deciding whether an existing measure is good enough for the use you're putting it to. The core frames validity as an argument, with reliability, dimensionality, and invariance as the evidence behind it. Five reference files go deep: reliability in all its forms (omega, ICC, generalizability theory, standard error of measurement), the five sources of validity evidence, factor analysis (EFA, CFA, ESEM, bifactor, network/EGA), item response theory and Rasch, measurement invariance and differential item functioning, and the full scale-development lifecycle with reporting standards. Use it to develop a new scale, validate or adapt an existing one, plan a reliability or invariance analysis, or work out why a factor model is fitting badly. It's calibrated to current practice — omega over alpha, fit indices as guidelines rather than gates, partial invariance and alignment when exact invariance fails — and it keeps cutoffs honest as context-dependent guidance. Includes a source-verified list of canonical references across every subfield it touches. Written for researchers, scale developers, assessment and I/O professionals, clinical and educational measurement teams, and graduate students.

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    Permissions

    Read Files
    Write Files

    File Scopes

    *.md
    *.txt
    *.docx
    references/**
    *.csv

    Pure Markdown guidance — no scripts, network calls, or secrets. It needs read access only to whatever you give it (items, CFA/IRT output, notes); write access is optional for saving a plan or report. No terminal, browser, network, or environment-variable access.

    Works in Claude Code, Cursor, Codex CLI, OpenClaw, and any SKILL.md-compatible agent. Pure Markdown with progressive disclosure (a core file plus reference files loaded on demand); no scripts, network, or setup. Best on frontier models, where the agent reasons over the methodology rather than pattern-matching.

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