> Second, we measure engagement of specific events on the page (e.g. when a misspelling message is displayed, and when it is clicked). This allows us to run experiments where we can test different misspelling messages and use CTR (click through rate) to determine the message's efficacy. If you are looking at network requests, these are the ones going to the one-pixel image at improving.duckduckgo.com. These requests are anonymous and the information is used only by us to improve our products.

The Firefox network logger does show requests to this domain when I click on a link in the search results, before the page navigates away. This suggests to me they might by logging this information. To be clear, this is speculation on my part, because I haven't examined the URL parameters in detail.

In any case, I'm not sure how much this manages to improve the results, since usually I can get help with my Python query (for example) using whatever crappy blog post is first in the results, but results from the official docs or StackExchange are still probably better and should be prioritized.

Any system that ranks things purely based on votes or view counts can have a feedback loop that can amplify "bad" results that happen to get near the top for whatever reason. For web search, this would encourage results that look right from the results page, even if they're not actually a good result of what the user is looking for.

An example of this would be when you're trying to find an answer to a specific question like "How do I do X when Y?". The best result I'd hope for is a page that answers the question (or a close enough question to be applicable), while the promising-looking-but-actually-bad result is a page where someone asks the exact same question but there are no answers.

I think this is a place where Google has pretty obvious algorithm problems. For example, I’m building a personal website for the first time in many years, and obviously that means I’m doing a fair bit of looking up new or forgotten webdev stuffs. It’s widely known that W3Schools is low quality/high clickbait/has a long history of gaming the SEO system. They’ve been penalized by Google’s algorithm rule changes but continue to get the top result (or even the top 3-5 results!), even with Google having a profile of my browsing habits, and knowing that I intentionally spend longer on these searches to pick a result from MDN or whatever. It seems pretty likely that W3Schools is just riding click rate to stay at the top. And it’s pathological.

for some languages, W3schools is as good a reference or better than the official documentation.

And they're definitely better than most seospam.

Edit: I semi-intentionally forgot to mention Stack Overflow because it’s so unpredictable in terms of quality.