To me it's not clear that it should be interpreted as an improvement: what I read in this summary is that users had to search more and to enter longer queries to get to what they needed.
Users struggle to find the right stuff or stuff that‘s so good they don‘t need do do more queries.
> a 30% rise in maximum query length per user, and a 10% increase in average query length
Users need to execute more complex queries to find what they are looking for.
I can imagine that's why today's apps suck so much as most of the pain points won't be easily caught by user behavior metrics.
One thing Alex from Organic Maps taught me is how important it is to just listen to your users. Many of the UX improvements were driven by addressing complaints from e-mail feedback.
But the opposite is equally possible: a terrible search tool could regularly fail to find what the user is looking for or produce music that they enjoy. In this situation, I can also imagine users searching more, because it takes more search effort to find something they like.
They key is why are users searching. In Spotify's case I imagine that you could try and connect number of searches per listen, or how often a search results in a listen and how often those listens result in a positive rating. There are probably more options, but there needs to be some way of connecting the amount of search with how the user feels about those search results.
And yeah, using nothing other than search volume is probably a bad way to go about it
The only way is to use the product yourself and honestly engage with it. Stats can't answer this question.
Nin, NIN, nine inch nails, Trent Reznor
VS
Nin, pantera, nail bomb, muse
This should be easy to differentiate, with a "[someone's name] distance algorithm" or such, right?