Point-biserial correlation API

Computes the point-biserial correlation between a dichotomous (0/1) variable and a continuous variable, with the two group means and standard deviation. Answers 'How well does this item predict total score?', 'What is the point-biserial r between a 0/1 and a continuous measure?'.

Price$0.04per request

MethodPOST

Route/v1/stats/point-biserial

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

psychometricspoint-biserialcorrelationitem-discriminationdichotomoustest-theoryvalidityscoring

API URLhttps://x402.hexl.dev/v1/stats/point-biserial

Integration docs

Example request

{
  "binary": [
    1,
    1,
    0,
    1,
    0,
    0,
    1,
    0
  ],
  "continuous": [
    20,
    18,
    12,
    19,
    11,
    9,
    17,
    8
  ]
}

Example response

{
  "pointBiserial": 0.951817,
  "meanGroup1": 18.5,
  "meanGroup0": 10,
  "n": 8,
  "n1": 4,
  "n0": 4,
  "sd": 4.4651,
  "interpretation": "strong association"
}

Input schema

{
  "type": "object",
  "required": [
    "binary",
    "continuous"
  ],
  "properties": {
    "binary": {
      "type": "array",
      "items": {
        "type": "number"
      },
      "description": "0/1 values",
      "examples": [
        [
          1,
          1,
          0,
          1,
          0,
          0,
          1,
          0
        ]
      ]
    },
    "continuous": {
      "type": "array",
      "items": {
        "type": "number"
      },
      "examples": [
        [
          20,
          18,
          12,
          19,
          11,
          9,
          17,
          8
        ]
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}