> The ideal question or problem from our perspective is is one that is equally challenging for everyone
It seems like you could solve this by asking a question no one has ever been exposed to before, or by exposing each candidate to the theory relevant to the question yourself.
Except that the first strategy is guaranteed to fail some of the time, because there are no questions like that.
There is an interesting communication problem here.
If I could guarantee that every candidate would read my blog, I'd happily point them to an essay like this, and then in the interview we could work on something meaty, like pattern matching.
That would suit your second recommended strategy. But I wouldn't want to write an essay like this, and then favour those candidates who like to read Hacker News or follow me on Twitter. We're trying to select for talent, not for membership in a tribe :-)
So we're retiring this question, and we already have a few replacements that we use for many candidates. But I won't blog about them, in an attempt to hew closely to the first strategy you suggest.
I think you could pretty easily guarantee that every candidate will read email from you (where "you" are their point of contact with the company) prior to the interview. Why do you need to direct them to the essay from your blog?
It seems like you could solve this by asking a question no one has ever been exposed to before, or by exposing each candidate to the theory relevant to the question yourself.
Except that the first strategy is guaranteed to fail some of the time, because there are no questions like that.
Why not go the other way?