tsb — A/B Test — Examples

1 · Conversion rate by variant

Each row is one user session: which arm they were in, whether they converted, and order value.

TypeScript

import { DataFrame } from "tsb";

const variant = [
  "A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A",
  "B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B",
];
const converted = [
  0,1,0,0,1,0,0,0,1,0, 1,0,0,0,1,0,0,1,0,0,   // 5 / 20 = 25%
  1,1,0,1,0,1,1,0,1,0, 1,1,0,1,1,0,0,1,1,1,   // 13 / 20 = 65%
];
const order_value = [
  0, 42, 0, 0, 35, 0, 0, 0, 51, 0, 28, 0, 0, 0, 60, 0, 0, 33, 0, 0,
  47, 51, 0, 39, 0, 64, 38, 0, 55, 0, 41, 47, 0, 33, 58, 0, 0, 49, 36, 52,
];

const sessions = DataFrame.fromColumns({ variant, converted, order_value });

const summary = sessions.groupby("variant").agg({
  converted:   "mean",
  order_value: "mean",
}, false);
const out = summary.rename({
  converted:   "conv_rate",
  order_value: "avg_order_value",
});
console.log(out.toString());

const a = Number(out.col("conv_rate").iloc(0));
const b = Number(out.col("conv_rate").iloc(1));
const lift = ((b - a) / a) * 100;
console.log(`\nLift in conversion rate: ${lift.toFixed(1)}%`);

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2 · Order value distribution per variant

Use describe to compare full distributions, not just means.

TypeScript

import { DataFrame, describe } from "tsb";

const variant = [
  "A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A",
  "B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B",
];
const order_value = [
  0, 42, 0, 0, 35, 0, 0, 0, 51, 0, 28, 0, 0, 0, 60, 0, 0, 33, 0, 0,
  47, 51, 0, 39, 0, 64, 38, 0, 55, 0, 41, 47, 0, 33, 58, 0, 0, 49, 36, 52,
];
const sessions = DataFrame.fromColumns({ variant, order_value });

// Filter to converted-only orders for AOV
const isConverted = sessions.col("order_value").map(v => Number(v) > 0);
const converted = sessions.filter(isConverted);

const isA = converted.col("variant").map(v => v === "A");
const isB = converted.col("variant").map(v => v === "B");
const a = converted.filter(isA).col("order_value");
const b = converted.filter(isB).col("order_value");

console.log("Variant A order values:");
console.log(describe(a).toString());
console.log("\nVariant B order values:");
console.log(describe(b).toString());

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🧪 A/B Test Results

1 · Conversion rate by variant

2 · Order value distribution per variant