Frequently Asked Questions

When conducting experiments, it is crucial to ensure that there is no cross-contamination between control and treatment groups and that data is accurately reflected in both funnel and summary views.

Cross-contamination can occur due to implementation issues, such as a race condition with tracking. This happens when users, particularly those with slower network connections, land on a control page and a page-view event is tracked before the redirect occurs.

To mitigate this, it is recommended to adjust the placement of tracking scripts. The Statsig redirect script should be positioned high in the head of the page, ensuring that it executes as early as possible. Meanwhile, page tracking calls should be made later in the page load lifecycle to reduce the likelihood of premature event tracking. This adjustment is expected to decrease discrepancies in tracking and improve the accuracy of experiment results.

Additionally, it is important to confirm that there are no other entry points to the control URL that could inadvertently affect the experiment's integrity. Ensuring that the experiment originates from the correct page and that redirects are functioning as intended is essential for maintaining the validity of the test.

Lastly, it is necessary to have specific calls in the code to track page views accurately. These measures will help ensure that the experiment data is reliable and that the funnel and summary views are consistent.