I think it would come down to a matter of degree. A slight change in the order of results is pretty meaningless either way. But major alterations, where some pages are relatively inaccessible, could obviously be an impediment to getting the results we want.
Let me try this example: Suppose your searches are primarily academic. Let's say that whenever you search the term "momentum" you are looking for something scientific- ballistics, elementary particles, whatever. But one day you are writing a blog in which you want to search for background, but you need to use a non-scientific meaning of the same word. Perhaps a psychic used the term and you are debunking. The particular case is irrelevant. The point is tha if personalization is too aggressive you may not find the info most relevant to your interests.
This isn't privacy FUD or anything, just a pragmatic warning. The FUD comes when you start thinking about how their algorithms might actually decide which results you are "interested" in. Thinking of Google, what bu siness are they in? What about you behavior on the web most interests them? Would they decide that the most interesting things to you are the ones on which you clicked the most ads?
But whatever change personalized search makes relative to generic search, the opposite change will occur going from personalized to generic. To penalize personalized search when the change is of equal magnitude going either direction doesn't seem fair. As long as the personalizations are just a transformation and not a subtraction, the two options are just mirror images of each other. They have the exact same kind of failure condition. The question is just which one's failure conditions are more likely to occur.
As a counter-example: Suppose your searches are primarily academic. Let's say that whenever you search the term "momentum" you are looking for something scientific- ballistics, elementary particles, whatever. But most people aren't looking for scientific info, so you constantly have to dig and dig to find anything relevant on Google. The point is, if the search technology is too impersonal, you may not find the info most relevant to your interests.
As long as the personalizations are just a transformation and not a subtraction
This is the crucial point. As long as it's accessible, I can get what I want by search refinement either way (but I would imagine that it would be easier for me to refine in the space in which I am familiar than to refine in the unfamiliar space). Giving me the (easy) option to turn it off is a good idea for search.
Let me try this example: Suppose your searches are primarily academic. Let's say that whenever you search the term "momentum" you are looking for something scientific- ballistics, elementary particles, whatever. But one day you are writing a blog in which you want to search for background, but you need to use a non-scientific meaning of the same word. Perhaps a psychic used the term and you are debunking. The particular case is irrelevant. The point is tha if personalization is too aggressive you may not find the info most relevant to your interests.
This isn't privacy FUD or anything, just a pragmatic warning. The FUD comes when you start thinking about how their algorithms might actually decide which results you are "interested" in. Thinking of Google, what bu siness are they in? What about you behavior on the web most interests them? Would they decide that the most interesting things to you are the ones on which you clicked the most ads?