Google on Why Field Data is More Reliable Than Lab Data

Google’s Martin Splitt explains the distinction between lab data & field data as it identifies with testing tools.

Splitt says we can be more dependent on field data as field data shows how genuine the user interaction is with the website.

This point was raised during a Google Webmaster Javascript SEO Meet. A site proprietor presented an inquiry posing to why there’s a distinction between field Data and lab data when estimating page speed.  

Here’s Splitt’s response,

“Field data is coming from real users, whereas lab data comes from a quite strong machine with probably good internet from somewhere around the world. So you might not see the same results.”

Field Data vs. Lab Data

Splitt offers a speculative case of testing a website with a tool that utilizes lab data from a nation where the web site’s server is additionally based. In this model, the lab data would almost certainly decide the site loads very quickly. It is because the website is facilitated in the same region, so the real-time it takes to send information is negligible. Suppose the region is covered with rapid internet access which will speed up the website by the lab data.

In any case, that speed drops extensively when the website users are situated in another region. The speed drops significantly further if users don’t have a fast internet connection where they live and is the key contrast between lab and field information.

Why is Field Data More Reliable?

Lab data information is estimated with a controlled test under perfect conditions. In contrast, field data information is determined by how genuine clients collaborate with a site under an assortment of conditions.

As Martin Splitt puts it:

“In that case, my lab data looks amazing. And then my field data, because my users are sitting on the other end of the world, looks terrible. That’s what happens because the lab data is only synthetic. It’s only an approximation of what happens in the real world. And then you have field data which, surprisingly, gives you the actual thing that people are experiencing.

 

So if you know that you are serving users on slow, old phones. Or rural, spotty, internet connections. This is what happens. This is when the field data looks a lot worse than what you see in lab data.

 

That’s a general problem – developers usually work with fantastic internet connections on modern laptops. And then the real world user is on an old iPhone 2, somewhere in rural, northern Germany where you have Edge internet connection if you are lucky. And then everything looks terrible for them…

 

Field data is probably a better indicator for how real users are experiencing your website than lab data. Because lab data is literally just someone’s server making a request to your thing. And then if that server happens to be quite beefy then you get pretty good looking numbers, but then the real world isn’t as beefy and nice.”