The Bayesian API at abtestapi.io provides an endpoint that returns the Bayesian "Chance to Beat" scores for A/B/n tests.
The primary use case is integrating Bayesian results into Google Sheets (using the "IMPORTDATA" function). By default the output with be returned in .csv (download) format, since this is required for the Google Sheet ImportData function.
JSON formatted output for other uses is also possible by using the 'output=json' parameter.
Access is granted by using a company-specific token that is provided to you by Online Dialogue. Please note after March 3rd 2020, requests without a valid token will no longer work.
Calling the url 'https://abtestapi.io/bayes', followed by required query parameter token with your company-specific token, and parameters a & b (required) for users and conversion in the control group (separated by '|' pipe symbol). Optionally additional variations can be added using c, d, ... j parameters.
The url request will return a .csv formatted result, which can be used in the import function in Google Sheets.
The output will show a chance between 0 and 1 for each of the variants, with 4 digits accuracy. The number of samples and output format can be configured (see API Reference).
|Google Sheets Formula||=IMPORTDATA("https://abtestapi.io/bayes?token=[YourTokenHere]&a="&B2&"|"&C2&"&b="&B3&"|"&C3)|
|Output options||Google Sheet showing various output options.|
|token||required||Unique company-specific token, provided to you by firstname.lastname@example.org.
Please note after March 3rd 2020, requests without a valid token will no longer work.
|a||required||Users & Conversions in A: Control, separated by a pipe '|' symbol.
For example for 3010 users with 153 conversions: a=3010|153
|b||required||Users & Conversions in B: Variant, separated by a pipe '|' symbol.
For example: b=3020|164
|c, d, e .. j||optional||Additional variants for AB Test with more than 2 variants. Same format as a, b.|
full (default) - all output options enabled (Variant, Bayesian Score, 95% Credible interval (Low95, High95).
singleScore - Only the Bayesian Score of variant B is returned (A/B-test only).
scores - Return scores for all variants
scoresInterval - Return scores & credible intervals for all variants
json - Return all output in json format with (as opposed to .csv which is otherwise returned)
For more information on output options, see this example sheet.
|samples||optional||Number of samples to use for the Monte Carlo Bayesian inference. Default = 50000. The higher the number, the longer processing time it will take. Maximum 5 million samples is allowed.|