Field note 01
Building a Rendering Baseline
A useful rendering comparison begins with a source document that is small, stable and easy to identify.
Start with one known state
Record the original title, description, links and visible text before introducing a scripted change. Stable markers make it possible to distinguish an intentional transformation from an unrelated page update.
Change one variable
Comparisons are easier to interpret when only one condition changes. A JavaScript-on and JavaScript-off pair is more informative when the URL, response headers and source document stay the same.
Keep observations modest
Small pages produce cleaner evidence. They also reduce noise from third-party assets, asynchronous widgets and unrelated network activity.