Free demo, no signup. EU-hosted. R under the hood.

Psychometrics, fairness analysis and APA reports, in the browser.

Run the full test-validation stack on your data: reliability, factor analysis, IRT, measurement invariance and norms, plus adverse-impact and item-level DIF checks. Then let Claude draft the results section in APA 7 or plain language. No install, no code required, and R when you want it.

24 analysis modules APA 7 and plain-language reports lavaan, mirt, lordif, pROC and psych behind every number Deep-linkable and agent-friendly
What it does

Four things SPSS, JASP and jamovi don't do out of the box

One workbench for test development, fairness evidence, written reports and data that lives in a database.

Psychometrics stack

Everything a technical manual or validation paper asks for.

  • Reliability: alpha, omega, split-half, item analysis, optional Bayesian estimation
  • EFA with KMO, Bartlett and parallel analysis; CFA with fit indices and path diagrams
  • IRT from 1PL to graded response and GPCM, with Wright maps
  • Measurement invariance: configural, metric, scalar, strict
  • Normative tables (percentiles, T-scores, stanines), clinical cut-offs with ROC
  • Construct and criterion validity: AVE, CR, HTMT, known groups

Fairness pack

The adverse-impact evidence stack, layered the way reviewers read it.

  • Selection rates and the four-fifths rule with z-tests and Holm correction
  • Pairwise Cohen's d for practical significance
  • Item-level DIF: Mantel-Haenszel, logistic, and lordif with ETS A/B/C flags
  • Multi-group invariance on the assessment itself
  • Tutorials written for certification reviewers and counsel, not statisticians

Reports written for you

Every analysis has an Add to report button. Claude drafts the narrative.

  • APA 7 or plain-language style, per section
  • Executive, technical, full or custom report types
  • Export to Word or HTML; every number traces to R output you can inspect
  • Bring your own Anthropic key on Team plans

Your data, where it lives

Upload a file, or connect the database your responses already sit in.

  • CSV and Excel upload; PostgreSQL, MySQL, SQL Server and SQLite connections
  • Visual query builder with saved presets and JSON column expansion
  • Sandboxed R console over the loaded dataset, with the script downloadable
  • MCP endpoints so Claude Code and Cowork can run analyses without the UI

Plus the everyday toolkit: ANOVA, regression, correlation, chi-square, mediation and moderation, path analysis, cluster analysis, power analysis, time series and text analysis.

Who it's for

Built with the people who have to defend the numbers

Assessment publishers and certification bodies

A read-only workbench on your live response database. Pick a test and a date range, every item arrives labelled with its question text, and the technical report is drafted for you.

In production for a personality-test publisher since spring 2026.
Book a schema-fit review

I-O consultancies and bias auditors

The complete adverse-impact evidence stack for NYC Local Law 144, California ADS and EU AI Act work: four-fifths, effect sizes, item-level DIF and invariance, with a client-ready summary and an APA appendix.

Bill for judgment and the signature, not for rebuilding tables.

Researchers validating scales

CFA, graded-response IRT, DIF by language or sex, measurement invariance, cut-offs and norms without writing R, and the R script downloadable when a reviewer asks for it.

Same packages your methods section already cites.

Instructors and students

A browser lab students open from one link. Nothing to install, APA output scaffolded, and a sandboxed R console for the students who want to see the code.

Student pricing with an academic email. Free instructor seats on request.
Case study

Embedded psychometrics for a personality-test publisher

Their research lead was iterating scales against hundreds of completions a day, and every analysis started with an engineer export, a clean-up and a codebook. We put a branded instance of DataWeaver directly on their production database.

Ask for the reference
  • Read-only connection to their live PostgreSQL. No schema changes on their side.
  • Around 150,000 responses per load, with cached weekly segments so a daily pull stays fast.
  • Question text carried as the variable label into every analysis, from reliability to DIF.
  • Four modules built on the engagement and now in the core product: disparate impact, item-level DIF, normative data, Bayesian reliability.
  • Their analysts can run R against the same live datasets from Claude Code over MCP.
How it works

Three steps from data to a results section

1

Load your data

Upload CSV or Excel, connect a database, or start with a built-in demo dataset.

2

Choose the analysis

Pick from 24 modules. The AI advisor suggests one from your data and research question.

3

Build the report

Add results to the report queue, let Claude draft the narrative, export to Word or HTML.

Pricing

Start free. Pay when it earns its place.

Self-serve plans below. Organisation plans are quoted, because they come with setup.

Free demo

$0

Explore with built-in datasets

  • All analysis modules
  • Demo datasets only
  • APA formatted output
  • No signup

Student

$29 /month

For students with an academic email

  • Everything in Pro, one seat
  • Upload your own data
  • Claude-drafted reports
  • Verified at checkout with your academic email

Faculty and clinical researchers: ask about Academic Annual at $600 per year.

Team

$599 /month

For consultancies and research groups

  • Everything in Pro
  • Up to 5 members
  • Shared workspace and invites
  • Bring your own Anthropic key
  • Audit trail
  • Priority support

Team Compliance

$999 /month

Team plus the fairness pack for firms delivering adverse-impact and bias-audit work: four-fifths with z-tests and Holm, Cohen's d, item-level DIF, invariance, counsel-ready report styles, JSONL audit trail for record retention, and two hours of methods consultation a quarter.

Talk to us

Embedded / white-label

from $1,500 /month + setup

Your brand, your domain, a read-only connector to your response database with question text as labels, the full stack, MCP access for your analysts. Hosted on our EU infrastructure or deployed on yours. Setup is a quoted two-to-four-week project.

Book a schema-fit review

Classroom and department

from $2,500 /section/term

Course workspace, deep-linked assignments, term-limited student accounts without individual billing, free instructor seats. Department licences from $6,000 a year.

Ask about a pilot

Need it done for you? Scale validation reports, adverse-impact and DIF evidence packs, and technical report sections, run in DataWeaver and reviewed by a psychometrician, from $1,500. Ask us.

Security and straight answers

What you will want to know before uploading anything

Where does my data go?

The app runs on servers in the EU (Hetzner, Germany) over HTTPS. Uploaded files are processed in your session. Database credentials are held server-side as environment variables and never reach the browser. Report drafting sends the statistical output, not your raw data, to the Anthropic API; on Team plans you can use your own key.

Do you have SOC 2 or ISO 27001?

Not yet. DataWeaver is a small company and we would rather say so than imply otherwise. We will sign your data-processing agreement, we recommend starting with de-identified data, and for organisations that need it we deploy the embedded edition on your own infrastructure.

Can I check the numbers?

Yes. The engine is standard R: lavaan, mirt, lordif, difR, pROC and psych, with package versions locked. Paid plans include a sandboxed R console over your loaded dataset, and you can download the script and run it in plain R.

Is the AI report a black box?

No. Claude drafts the narrative from the actual output (fit indices, loadings, flags, effect sizes). Every figure in the text comes from the tables above it, the draft is editable, and a named person should still sign it.

Which file types can I upload?

CSV and Excel (.xlsx, .xls), or a direct database connection. SPSS .sav files are not supported yet; export to CSV from SPSS and the variable names carry over.

Can an AI agent drive it?

Yes. Every tab is deep-linkable, buttons have stable labels, and the MCP endpoints let Claude Code or Cowork list datasets, read schemas and run R scripts in the same sandbox the app uses.

See it on your own data

Start with the demo, or send us a de-identified extract and we will run it through and send you the report.

Book a walkthrough