Case Study: SLT

Using the SLTrib.com as a Case Study for A/B Testing

Overview

SLTrib.com is serving as a case study for implementing A/B testing directly within a newsroom environment. Our goal is to assess how different design and content strategies impact user engagement. By segmenting users into control and experiment groups, we can measure the effectiveness of changes to our website.

User Segmentation

We are segmenting users using a client-side approach that ensures a consistent experience across visits. Our method assigns each user to either a "control" or "experiment" group based on their browser cookies and a randomization function. This segmentation allows us to test variations in design, layout, and content delivery.

Key Metrics for Analysis

After implementing A/B tests, we will track and analyze the following metrics:

• Clicks: How users interact with elements such as headlines, buttons, and links.

• Newsletter Subscriptions: Whether the experiment group results in more newsletter sign-ups.

• Donations: The impact of content changes on reader contributions.

Implementing Your Own A/B Testing with JavaScript

Below is a generic implementation of our segmentation logic that newsrooms can copy and modify for their own testing needs and code stacks. This script assigns users to either a control or experiment group and caches their assignment to ensure a consistent experience. Feel free to take this to your developer or engineer on your team so they better understand what you are trying to achieve.

function getUserSegment() {
  const SEGMENT_KEY = "user_ab_segment";
  const existingSegment = localStorage.getItem(SEGMENT_KEY);
  if (existingSegment) return existingSegment;

  try {
    const bucket = Math.random() < 0.5 ? "control" : "experiment";
    localStorage.setItem(SEGMENT_KEY, bucket);
    return bucket;
  } catch (error) {
    console.error("Error assigning A/B test segment:", error);
  }

  return "control"; // Default to control group if an error occurs.
}

/**
 * Function to dynamically display content based on A/B test segment.
 *
 * @param {string} controlContent - The content for the control group.
 * @param {string} experimentContent - The content for the experiment group.
 *
 * @returns {string} The appropriate content based on the user's segment.
 */
function renderABTestContent(controlContent, experimentContent) {
  const segment = getUserSegment();
  return segment === "control" ? controlContent : experimentContent;
}

// Example usage:
const controlMessage = "Welcome to the original experience!";
const experimentMessage = "Welcome to the new experience!";

document.getElementById("ab-test-container").innerText = renderABTestContent(
  controlMessage,
  experimentMessage
);

How to Use This Code

This JavaScript function allows you to assign users to a control or experiment group and display different content based on their assignment.

1. User Assignment

• The getUserSegment function checks if a user has already been assigned a segment (control or experiment) stored in localStorage.

• If not, it randomly assigns them and stores the result for consistency across sessions.

2. Content Display

• The renderABTestContent function takes two content options: one for the control group and another for the experiment group.

• It returns the appropriate content based on the user's segment.

Implementation Example

1. Add an element in your HTML where the A/B tested content will appear:

<div id="ab-test-container"></div>

1. Include the Javascript file or place the script in your page.

2. Call the function to update the content dynamically:

const controlMessage = "Welcome to the original experience!";
const experimentMessage = "Welcome to the new experience!";

document.getElementById("ab-test-container").innerText = renderABTestContent(controlMessage, experimentMessage);

1. Each user will consistently see the same version of the content based on their assigned group.