Why did you choose that criteria?
Past experience, general considerations, inferences, all the usual stuff.
In the Internet age you decline much MUCH more content than you accept. The opportunity costs are noticeable and you pretty much have to prefilter your information flow if you don't want to be standing with your face in front of an operating water canon.
Given all this, the selection process is going to be noisy, slanted, and very much imperfect. I suspect that opportunities to improve it are going to revolve around more filtering, not less. That's a complicated and hugely influential process. Sticking an ad hominem label somewhere in there seems.. not the best idea.
Sticking an ad hominem label in there is accurate. More importantly, it lets you improve your filters with information on when ad hominem is generally correct - as opposed to incorrect. Throwing out the label because it offends your sensibilities limits your ability to use the information associated with that label.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.