运行 A/B 测试

使用共享存储空间 Worklet 运行 A/B 测试。

Shared Storage API 是一种 适用于通用的跨站点存储的沙盒提案，支持多种 可能的使用场景。A/B 测试就是这样一个例子 （在 Chrome 104.0.5086.0 及更高版本中）。

您可以将用户分配到某个实验组，然后将该组存储在“共享”中 要在跨网站环境中访问的存储空间。

尝试 A/B 测试

若要尝试对共享存储空间进行 A/B 测试，请确认您使用的是 Chrome 104.0.5086.0 或更高版本。启用 chrome://settings/adPrivacy 下的所有广告隐私权 API。

您还可以在命令行中使用 --enable-features=PrivacySandboxAdsAPIsOverride,OverridePrivacySandboxSettingsLocalTesting,SharedStorageAPI,FencedFrames 标志启用共享存储空间。

试用代码示例

要了解实验是否具有预期效果，您可以跨多个网站运行 A/B 测试。作为广告客户或内容制作者，您可以根据用户分配到的群组，选择呈现不同的内容或广告。群组分配会保存在共享存储空间中，但无法渗漏。

在此示例中：

  • ab-testing.js 应嵌入到一个帧中，该帧会映射一个对照组和两个实验内容。该脚本调用实验的共享存储 Worklet。
  • ab-testing-worklet.js 是一个共享存储空间 Worklet，它会返回用户分配到哪个群组，从而确定展示哪个广告。

ab-testing.js

// Randomly assigns a user to a group 0 or 1
function getExperimentGroup() {
  return Math.round(Math.random());
}

async function injectContent() {
  // Register the Shared Storage worklet
  await window.sharedStorage.worklet.addModule('ab-testing-worklet.js');

  // Assign user to a random group (0 or 1) and store it in Shared Storage
  window.sharedStorage.set('ab-testing-group', getExperimentGroup(), {
    ignoreIfPresent: true,
  });

  // Run the URL selection operation
  const fencedFrameConfig = await window.sharedStorage.selectURL(
    'ab-testing',
    [
      { url: `https://your-server.example/content/default-content.html` },
      { url: `https://your-server.example/content/experiment-content-a.html` }
    ],
    {
      resolveToConfig: true
    }
  );

  // Render the chosen URL into a fenced frame
  document.getElementById('content-slot').config = fencedFrameConfig;
}

injectContent();

ab-testing-worklet.js

class SelectURLOperation {
  async run(urls, data) {
    // Read the user's experiment group from Shared Storage
    const experimentGroup = await sharedStorage.get('ab-testing-group');

    // Return the corresponding URL (first or second item in the array)
    return urls.indexOf(experimentGroup);
  }
}

register('ab-testing', SelectURLOperation);

Use cases

These are only some of the possible use cases for Shared Storage. We'll continue to add examples as we receive feedback and discover new use cases.

Content selection

Select and display different content on different websites in fenced frames based on information collected in Shared Storage. The output gate for these use cases is URL selection.

  • Creative rotation: Store data, such as creative ID, view counts, and user interaction, to determine which creative users' see across different sites.
  • A/B testing: You can assign a user to an experiment group, then store that group in Shared Storage to be accessed cross-site.
  • Custom user experiences: Share custom content and calls-to-action based on a user's registration status or other user states

Generate summary reports

Collect information with Shared Storage and generated a noisy, aggregated summary report. The output gate for these use cases is the Private Aggregation API.

  • Unique reach measurement: Many content producers and advertisers want to know how many unique people saw their content. Use Shared Storage to record the first time a user saw your ad, embedded video, or publication, and prevent duplicative counting of that same user on different sites. You can then use the Private Aggregation API to output a summary report for your reach.
  • Demographics measurement: Content producers often want to understand the demographics of their audience. You can use Shared Storage to record user demographic data in a context where you have it, such as your first-party site, and use aggregated reporting to report on it across many other sites, such as embedded content.
  • K+ frequency measurement: Sometimes described as "effective frequency," there is often a minimum number views before a user will recognize or recall certain content (often in the context of advertisement views). You can use Shared Storage to build reports of unique users that have seen a piece of content at least K number of times.

Engage and share feedback

The Shared Storage proposal is under active discussion and subject to change in the future. If you try this API and have feedback, we'd love to hear it.