Statistics - lesson 5 | HackIndia Skills

Statistics - lesson 5 | HackIndia Skills | HackIndia

Example

Tiny split script

For a web project, assign a visitor once and save it in localStorage. This is enough for a demo, but not for serious production analytics.

Log the group and outcome to your backend, Google Sheet, Supabase table, or a CSV export. Check that both groups got similar numbers of users.

// Browser JS: assign A or B once per visitor
let variant = localStorage.getItem("variant");

if (!variant) {
  variant = Math.random() < 0.5 ? "A" : "B";
  localStorage.setItem("variant", variant);
}

// Example use
const button = document.querySelector("#submitBtn");
button.textContent = variant === "A" ? "Submit" : "Get result";

// When the user completes the action, log:
// { variant: "A", completed: true }

Example

Read the result

Use counts first. Percentages without counts can mislead, especially with small samples.

Here is a simple result you could put in your evidence section.

A: 9 completions out of 25 users = 36%
B: 14 completions out of 27 users = 52%
Difference: B is 16 percentage points higher
Plain-language insight: In this sample, "Get result" had more completions than "Submit".
Limitation: The sample is small and mostly came from hackathon friends, so it may not represent real users.

Tip

Use AI carefully

You can ask ChatGPT, Gemini, or Claude to help phrase the insight. Give it the counts, not just the percentages.

Check that it mentions sample size, does not say “proved”, and includes a limitation. Replace confident claims with “in this sample” or “suggests”.

Prompt:
Rewrite this A/B test result in plain language for a hackathon README.
Counts: A had 9 completions out of 25 users. B had 14 completions out of 27 users.
Do not claim causation beyond this test. Mention one limitation.

Run A Simple A/B Test

Why this matters

Single idea

Set up the test

Tiny split script

Do not peek too much

Read the result

Use AI carefully

Do this now

Quick check