hypothesis-testing

hypothesis-testing is a skill for Claude Code, Codex from danielrosehill/Claude-Data-Analyst-plugin. It costs 56 tokens per session (812 once invoked), scanned A, original, MIT.

A data-analysis workflow that checks a specific claim against a dataset and reports whether the data supports it, contradicts it, or cannot decide.

In plain words
What is it for?
For testing claims such as whether one customer group spends more, whether conversion differs by page, or whether two measures are related.
Why use it?
It turns a broad question into a defined comparison or relationship test, making the evidence and uncertainty explicit.

Skill for Claude CodeCodex

Part of the claude-data-analyst plugin — 14 skills shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/danielrosehill/claude-data-analyst-plugin/hypothesis-testing
Any agent
npx skills add danielrosehill/Claude-Data-Analyst-plugin --skill hypothesis-testing
Clone the repo
git clone --depth 1 https://github.com/danielrosehill/Claude-Data-Analyst-plugin

Made for: Claude Code, Codex.

Or install claude-data-analyst, the plugin that ships this one along with the rest of its 14 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for hypothesis-testing

README.md
[![agentmods](https://agentmods.dev/badge/skills/danielrosehill/claude-data-analyst-plugin/hypothesis-testing.svg)](https://agentmods.dev/skills/danielrosehill/claude-data-analyst-plugin/hypothesis-testing)
Your own site
<a href="https://agentmods.dev/skills/danielrosehill/claude-data-analyst-plugin/hypothesis-testing"><img src="https://agentmods.dev/badge/skills/danielrosehill/claude-data-analyst-plugin/hypothesis-testing.svg" alt="Measured on agentmods" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 812 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00056 $0.00812
Opus 5 $0.00028 $0.00406
Sonnet 5 $0.00011 $0.00162
Haiku 4.5 $0.00006 $0.00081

Measured 4d ago against content hash 86b6b23ed7b4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

hypothesis-testing scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/hypothesis-testing/SKILL.md · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hypothesis Testing

Rigorous first-pass evaluation of a user hypothesis against a dataset.

Inputs

  • Path to a dataset file or folder.
  • The hypothesis, stated in natural language (e.g. "customers in segment A spend more than those in segment B", "there's no difference in conversion by landing page").
  • Optional: desired significance level α (default 0.05).

Step 1 — Formalise the hypothesis

Before testing, restate the user's claim as:

  • H₀ (null): typically "no effect" / "no difference" / "no relationship".
  • H₁ (alternative): the user's claim, one- or two-sided as appropriate.
  • Variables involved: identify which columns map to the hypothesis, with their dtypes.
  • Test type selected based on the data shape (see decision table below).

Show this formalisation to the user and proceed unless they object.

Step 2 — Select a test

User hypothesis shape Variables Default test
Group A mean ≠ Group B mean 1 numeric + 1 binary categorical Welch's t-test (unequal var) or Mann-Whitney if non-normal
Difference across 3+ groups 1 numeric + 1 categorical One-way ANOVA or Kruskal-Wallis
Association between two categoricals 2 categoricals Chi-square (or Fisher's exact if small cells)
Correlation ≠ 0 2 numerics Pearson (linear) or Spearman (monotonic)
Proportion differs from value 1 binary One-sample proportion z-test
Paired before/after 1 numeric, paired Paired t-test or Wilcoxon signed-rank
Time trend 1 numeric + time Mann-Kendall or regression slope test

Check assumptions (normality via Shapiro-Wilk for small n or visual for large n; equal variance via Levene's) and fall back to the non-parametric counterpart when they fail.

Step 3 — Execute

Recommended: uv run --with pandas --with scipy --with statsmodels python -c '...'.

Report:

  • Sample size(s)
  • Effect size (Cohen's d, r, Cramér's V, odds ratio — whichever fits)
  • Test statistic and p-value
  • 95% confidence interval for the effect

Read the full file on GitHub · 71 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 71 lines · 56 tokens per session scan A 86b6b23ed7b4

Subscribe to this mod's changes

hypothesis-testing is a skill published in the GitHub repository danielrosehill/Claude-Data-Analyst-plugin (11 stars, last pushed 4mo ago), licensed MIT. It adds 56 tokens to every session and 812 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

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