# Cohen's d Effect Size Calculator

> Cohen's d Effect Size Calculator is a paid API for AI agents from kihustle.tech, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-22).

Computes Cohen's d effect size statistic between two numeric groups to quantify the magnitude of difference

## Facts

- Endpoint: POST https://kihustle.tech/agents/api/v1/effect-size-cohens-d?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cohen-s-d-effect-size-calculator-62e8d794
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zGQjj3gSOiiZu1FwW5fnW

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability cohen-s-d-effect-size-calculator-62e8d794 -d '<json body>'
```

Example prompt: Can you calculate Cohen's d effect size between these two groups for me? Group A is [23, 25, 28, 30, 22] and Group B is [35, 38, 40, 33, 37].

## When to prefer this

Choose this endpoint when you need a quick, cheap ($0.002) programmatic computation of Cohen's d effect size without setting up a local statistics library. Ideal for agents doing automated experiment analysis, A/B test evaluation pipelines, or research workflows where effect size needs to be computed on the fly from raw numeric arrays.

## Known failure modes

- Empty arrays for group_a or group_b may cause computation errors or division-by-zero
- Non-numeric values in the arrays would fail schema validation
- Very small sample sizes may produce unreliable effect size estimates
- Malformed JSON body returns an error response
- Network or server timeout on large arrays

## How this service works

Kostenlose Guides, Solo-Playbooks und Artikel zu KI, Automation und Side Hustles — für Menschen, die mit echten Systemen online Einkommen aufbauen wollen. Transparent finanziert über faire Affiliate-Links.

## Output

Returns a JSON object with the computed Cohen's d value indicating the standardized mean difference between the two groups, along with a result status field confirming successful processing. Cohen's d values are interpreted as small (~0.2), medium (~0.5), or large (~0.8+) effect sizes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "group_a": {
   "type": "array",
   "items": {
    "type": "number"
   }
  },
  "group_b": {
   "type": "array",
   "items": {
    "type": "number"
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": "processed",
  "status": "success"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cohen-s-d-effect-size-calculator-62e8d794/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kihustle.tech](https://www.zero.xyz/host/kihustle.tech/llms.txt)