# Understand Step Duration Calculations in Scenario Editor **Last reviewed:** September 29, 2026 Use this article to choose and interpret AIQ step-duration metrics such as DOM Complete, Server Response Complete, Full Page Loaded, Script Time, Ajax Time, and Next Step Ready. ## What changed in this article - Replaced Test Designer/Web Designer wording with Scenario Editor terminology while keeping browser PerformanceNavigationTiming context. - Clarified which timings come from the browser and which are calculated by AIQ, including the SPA behavior where browser timings may return 0. - Added guidance that Script Time is often closer to perceived user duration, while Ajax Time is mostly retained for backward compatibility. ## Validation workflow 1. Select the timing option that matches the question being answered: browser timing, user-perceived step time, or SPA readiness. 2. Compare AIQ output with browser performance timing only for browser-provided metrics. 3. Document the selected timing option when sharing reports so reviewers interpret duration values correctly. **Review note:** This update keeps the technical timing distinctions but removes older Designer/Web Designer naming and fixes readability around asynchronous behavior. --- Last updated: September 29, 2026 If you have feedback on this topic, contact .