Which of the following is not a best practice for improving page scannability?

The choice of not being a best practice for improving page scannability is grounded in the focus of scannability itself. Scannability relates primarily to how easily a user can navigate and process information on a page at a glance.

When evaluating the options, best practices for enhancing page scannability generally emphasize clear organization, visual cues, and effective titles that help users quickly understand the content and locate the information they need. Using descriptive page titles, distinct visual styles, and reviewing navigation are aligned with enhancing the user experience by making content more accessible and easier to digest.

Testing functionalities, while essential for ensuring that a system operates correctly and that information is stored properly, does not directly contribute to the design or structure of the page in a way that aids scannability. Therefore, this option stands out as unrelated to improving how easily users can scan and find information within a page context.