4 ms·

This study is flawed for a few reasons that I'd mentioned to the author when it was first published, but they ignored my comments. The main problem is that the

This study is flawed for a few reasons that I'd mentioned to the author when it was first published, but they ignored my comments. The main problem is that they confuse DOMInteractive for Time To Interactive. The two events are very different. DOMInteractive is a legacy event that refers to the time when JavaScript can safely interact with the DOM. This really has nothing (or very little) to do with user experience. Time to Interactive, on the other hand, is the time when a user can expect the page to respond quickly to interactions (clicks, scrolls, keypresses), ie, these user interactions should have no user perceivable latency. This is not a metric that has a corresponding browser event. It requires a bunch of post-processing based on various events. The researchers have made no attempt to calculate TTI. Source: I've been working in this area of research for 15 years.

Abishek_Muthian 6y ago
> I've been working in this area of research for 15 years Is the outcome of the research by CATCHJS different from what you have learnt?
- bluesmoon 6y ago
  Some recent results are at https://tech.bluesmoon.info/2020/11/understanding-emotion-for-happy-users.html https://tech.bluesmoon.info/2020/11/understanding-emotion-fo...
andrewmcwatters 6y ago
What way would you suggest measuring this? Duration between TTFB and when user events first get pumped?
- bluesmoon 6y ago
  The simplest way to measure impact on users would be to just use boomerang which gets you all of this out of the box: https://github.com/akamai/boomerang https://github.com/akamai/boomerang To do it yourself, you need a combination of PainTiming and measuring LongTasks or study the periodicity of setInterval/requestAnimationFrame The above works for synthetic as well as real users. If you're able to measure real users directly, then you'd also want to look at Input Delays, Rage Clicks, Dead Clicks, Missed Clicks, Scroll Jank.

Abishek_Muthian 6y ago

> I've been working in this area of research for 15 years Is the outcome of the research by CATCHJS different from what you have learnt?

bluesmoon 6y ago
Some recent results are at https://tech.bluesmoon.info/2020/11/understanding-emotion-for-happy-users.html https://tech.bluesmoon.info/2020/11/understanding-emotion-fo...

andrewmcwatters 6y ago

What way would you suggest measuring this? Duration between TTFB and when user events first get pumped?

bluesmoon 6y ago
The simplest way to measure impact on users would be to just use boomerang which gets you all of this out of the box: https://github.com/akamai/boomerang https://github.com/akamai/boomerang To do it yourself, you need a combination of PainTiming and measuring LongTasks or study the periodicity of setInterval/requestAnimationFrame The above works for synthetic as well as real users. If you're able to measure real users directly, then you'd also want to look at Input Delays, Rage Clicks, Dead Clicks, Missed Clicks, Scroll Jank.