>Why, what would you expect?

I'd expect to see some of the much touted "search intelligence", NLP, term inference, vector term analysis, and AI in action...

This is the only interface you really get into the amazon catalog. What if you really are looking for shirts that don't have stripes? How would you formulate the query?

I think it depends on the application. If I’m searching for products in a store I do want “shirts without stripes” to give me shirts without stripes. I have a hard time thinking of a case when including results with the word “without” would be useful when it comes to online shopping.

When I’m looking up information, like an article, especially technical information, then yes I want the search engine to do as little interpreting as possible. That’s because any interpretation rules it uses won’t always be relevant so I’d rather have more control.

But for Amazon? I don’t see how someone can see the average user typing “shirts without stripes” and getting almost nothing but shirts with stripes, and going “yup, works as expected”.

> and guess what I probably wanted

How is interpreting "shirts without stripes" as "I wish to see shirts that don't have any stripes" guessing?

I would venture to say that most people (meaning your use case is in the minority) who type "shirts without stripes" want to see results showing shirts without stripes not results "containing words "shirt", "stripes" and "without".

I think what is happening here is that you know how search engines work and so you are conditioned to expect them to do what they're doing.

Exactly. Those who want the search engine to "understand" what they are asking for when they use words like "without" may not have thought through the unintended consequences. For there is no combination of search terms that might not be interpreted in a variety of ways that the searcher never imagined, because of the ambiguity of natural language. Better to learn and use search operators, and the strategies of careful choice of keywords.

Exactly. If you want shirts without stripes then just search "shirt -stripes" (https://www.google.com/search?q=shirt+-stripes)

Precisely, as there is a better way to do it. Search for "solid-colored shirt" or "black shirt" and/or further define your search to exclude the term "stripes."