>So is there an ideally sized choice set when it comes to dating—one large enough to include variety and depth, yet small enough that you can fairly weigh each prospect’s potential without tripping your brain’s overload switch? [...] Fisher puts people somewhere in the middle of that range. “Once you’ve met nine people who are vaguely in the ballpark, choose one and get to know that person better. If nothing works in…
If your goal is to do expectimax optimization, as decision theory would dictate, you should make a decision after reviewing sqrt(n) applicants. That's assuming a uniform distribution of utility among secretary choices. If the distribution is non-uniform, another heuristic might be better.