Tags: measurements



Tuesday, April 20th, 2021


Core web vitals from Google are the ingredients for an alphabet soup of exlusionary intialisms. But once you get past the unnecessary jargon, there’s a sensible approach underpinning the measurements.

From May—no, June—these measurements will be a ranking signal for Google search so performance will become more of an SEO issue. This is good news. This is what Google should’ve done years ago instead of pissing up the wall with their dreadful and damaging AMP project that blackmailed publishers into using a proprietary format in exchange for preferential search treatment. It was all done supposedly in the name of performance, but in reality all it did was antagonise users and publishers alike.

Core web vitals are an attempt to put numbers on user experience. This is always a tricky balancing act. You’ve got to watch out for the McNamara fallacy. Harry has already started noticing this:

A new and unusual phenomenon: clients reluctant (even refusing) to fix performance issues unless they directly improve Vitals.

Once you put a measurement on something, there’s a danger of focusing too much on the measurement. Chris is worried that we’re going to see tips’n’tricks for gaming core web vitals:

This feels like the start of a weird new era of web performance where the metrics of web performance have shifted to user-centric measurements, but people are implementing tricky strategies to game those numbers with methods that, if anything, slightly harm user experience.

The map is not the territory. The numbers are a proxy for user experience, but it’s notoriously difficult to measure intangible ideas like pain and frustration. As Laurie says:

This is 100% the downside of automatic tools that give you a “score”. It’s like gameification. It’s about hitting that perfect score instead of the holistic experience.

And Ethan has written about the power imbalance that exists when Google holds all the cards, whether it’s AMP or core web vitals:

Google used its dominant position in the marketplace to force widespread adoption of a largely proprietary technology for creating websites. By switching to Core Web Vitals, those power dynamics haven’t materially changed.

We would do well to remember:

When you measure, include the measurer.

But if we’re going to put numbers to user experience, the core web vitals are a pretty good spread of measurements: largest contentful paint, cumulative layout shift, and first input delay.

(If you prefer using initialisms, remember that CFP is Certified Financial Planner, CLS is Community Legal Services, and FID is Flame Ionization Detector. Together they form CWV, Catholic War Veterans.)

Friday, March 12th, 2021

The Performance Inequality Gap, 2021 - Infrequently Noted

Developers, particularly in Silicon Valley firms, are definitionally wealthy and enfranchised by world-historical standards. Like upper classes of yore, comfort (“DX”) comes with courtiers happy to declare how important comfort must surely be. It’s bunk, or at least most of it is.

As frontenders, our task is to make services that work well for all, not just the wealthy. If improvements in our tools or our comfort actually deliver improvements in that direction, so much the better. But we must never forget that measurable improvement for users is the yardstick.

Monday, December 14th, 2020

Cloudflare’s privacy-first Web Analytics is now available for everyone

Cloudfare’s alternative to Google Analytics is now available—for free—regardless of whether your a Cloudflare customer or not:

Being privacy-first means we don’t track individual users for the purposes of serving analytics. We don’t use any client-side state (like cookies or localStorage) for analytics purposes. Cloudflare also doesn’t track users over time via their IP address, User Agent string, or any other immutable attributes for the purposes of displaying analytics — we consider “fingerprinting” even more intrusive than cookies, because users have no way to opt out.

Monday, November 16th, 2020

The Core Web Vitals hype train

Goodhart’s Law applied to Google’s core web vitals:

If developers start to focus solely on Core Web Vitals because it is important for SEO, then some folks will undoubtedly try to game the system.

Personally, my beef with core web vitals is that they introduce even more uneccessary initialisms (see, for example, Harry’s recent post where he uses CWV metrics like LCP, FID, and CLS—alongside TTFB and SI—to look at PLPs, PDPs, and SRPs. I mean, WTF?).

Monday, July 27th, 2020

Is my host fast yet?

This is an interesting project to try to rank web hosts by performance:

Real-world server response (Time to First Byte) latencies, as experienced by real-world users navigating the web.

Friday, May 8th, 2020

Designing for Progressive Disclosure by Steven Hoober

Progressive disclosure interface patterns categorised and evaluated:

  • popups,
  • drawers,
  • mouseover popups (just say no!),
  • accordions,
  • tabs,
  • new pages,
  • scrolling,
  • scrolling sideways.

I really like the hypertext history invoked in this article.

The piece finishes with a great note on the MacNamara fallacy:

Everyone thinks metrics let us measure results. But, actually, they don’t. They measure only what they are measuring. Engagement, for example, is not something that can be measured, so we use an analogue for it. Time on page. Or clicks.

We often end up measuring what is quick, cheap, and easy to measure. Therefore, few organizations regularly conduct usability testing or customer-satisfaction surveys, but lots use analytics.

Even today, organizations often use clicks as a measure of engagement. So, all too often, they design user interfaces to generate clicks, so the system can measure them.

Monday, February 24th, 2020

Web bloat

Pages are often designed so that they’re hard or impossible to read if some dependency fails to load. On a slow connection, it’s quite common for at least one depedency to fail.

Fire up Reader Mode and read this excellent article informed by data from using a typically slow connection in rural USA today. Two findings are:

  1. A large fraction of the web is unusable on a bad connection. Even on a good (0% packetloss, no ping spike) dialup connection, some sites won’t load.
  2. Some sites will use a lot of data!

Saturday, February 15th, 2020


This is so useful! Get instant results from Google’s Chrome User Experience Report without having to wait (or pay) for BigQuery.

Here’s an example of my site’s metrics over the last few months, complete with nice charts.

Saturday, November 17th, 2018

New kilogram standard: how the SI unit of mass is being redefined - Vox

A fascinating look at standards in the real world. In this case, it’s the kilogram, which is shedding its French Revolutionary roots in favour of the Planck constant.

Our messy human measurements have transcended their messy humanness; they have been melded with an eternal truth.

Mention of The Master Of The Kilogram reminded me of The Keeper Of Time.

Thursday, September 6th, 2018

Unit deconverter - make your units less useful!

Take a perfectly useful standardised measurement of length, weight, speed or time, and convert to something far less useful (but much more fun).

Thursday, December 21st, 2017

Net Promoter Score Considered Harmful (and What UX Professionals Can Do About It)

Jared’s spot-on takedown of Net Promoter Scores.

(Andy feels this is like criticising GDP, but GDP measures something that actually happened, whereas NPS, like horoscopes or tea-leaf readings, rely on clairvoyance.)

Monday, September 25th, 2017

Why it’s tricky to measure Server-side Rendering performance

A good analysis, but my takeaway was that the article could equally be called Why it’s tricky to measure Client-side Rendering performance. In a nutshell, just looking at metrics can be misleading.

Pre-classified metrics are a good signal for measuring performance. At the end of the day though, they may not properly reflect your site’s performance story. Profile each possibility and give it the eye test.

And it’s always worth bearing this in mind:

The best way to prioritize content by building a static site. Ask yourself if the content needs JavaScript.

Thursday, August 23rd, 2007

GOOD 006 - Transparency - Weights and Measures

A really nice visual representation of just how isolated the Imperial system is.