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Analyze A/B Test Results
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Analyze A/B Test Results

MediumPython

Problem

Shopify Checkout experiments record one binary result per visitor: 1 for a completed purchase and 0 otherwise. Given control and treatment result vectors, analyze the experiment and determine whether the treatment conversion rate is significantly different at a 5% significance level.

Implement analyze_ab_test(control, treatment).

Formal Specification

  • Input: Two non-empty lists of integers, where each value is either 0 or 1.
  • Output: A dictionary containing control and treatment sample sizes, conversion rates, absolute lift, relative lift, z-score, two-sided p-value, and a boolean significant field.
  • Round numeric output values to four decimal places. If the control conversion rate is zero, return None for relative lift.
  • Use a pooled two-proportion z-test. If the pooled standard error is zero, return z_score = 0.0 and p_value = 1.0.

Constraints

  • 1 <= len(control), len(treatment) <= 10^6
  • Every vector value is either 0 or 1
  • The vectors may have different lengths
  • Use a two-sided significance threshold of 0.05

Function Signature

def analyze_ab_test(control, treatment):
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