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I was not equating this to a scenario where you are only looking for one watch. The expression (and anecdote behind it) is also used to describe managing accord
by braythwayt 8y ago
I was not equating this to a scenario where you are only looking for one watch. The expression (and anecdote behind it) is also used to describe managing according to metrics that are easy to collect, often at the expense of outcomes.
That applies in the case of caring more about false positives than false negatives, since nobody (or close enough) even knows how many false negatives they have.
Your statement that someone being successful elsewhere doesn't prove we have a false negative underscores the uncertainty involved. It doesn't invalidate what I'm saying in the least.
But if we want to be rigorous, we could do some direct testing. Let's say we give a telephone screening and four interviews to each candidate. Simpkifying somewhat, let's say that our policy is that a fail on any one eliminates the candidate.
If we hire lots of people, we can collect false positive and false negative stats by randomly passing someone who fails exactly one test.
If a lot of people who fail a particular test end up succeeding, we can infer that the test provides false negatives.
On the other hand, if everyone who gets the random "free pass" on one particular test ends up failing, we can presume it has low false negatives, and maybe abandon the random passes for that test.
- deleted 8y ago[deleted]
- ska 8y agoI understood the analogy you were trying to draw, I just disagree with it. The original joke/anectdote works because it leads to clearly suboptimal search - the guy knows his watch isn't near the streetlight, but he's looking there because he can see. This is a very different situation. To abuse the analogy further, the guys best bet to find a watch seems to be just looking near the streetlight. After all, not only can you see better there, but most of the watches are near there too.
- pandaman 8y agoWhat your opponent is saying is that the cost of false negatives is unknown because it's hard to calculate. So people only calculate the cost of of false positive because it's easy to calculate then compare it to the unknown value and conclude that it's greater, not dissimilar to the gentleman who had been looking for the watch under a streetlight. Your saying "false negative is only a cost to you if you fail to hire well for that position" could be easily disproved with examples of people, who were rejected and started their own competitive business (e.g. [1]). IMHO, one of the goals of having 10Ks of engineers on staff is to keep them from the competition. But since nobody is tracking this and the extreme cases like WhatsApp can be hand-waved away it's easy to pretend that the false negative's cost is miniscule. 1. https://en.wikipedia.org/wiki/WhatsApp#History https://en.wikipedia.org/wiki/WhatsApp#History
- ska 8y agoIf I’d seen any evidence that this cost wasn’t minuscule int the typical case, I’d be much more interested in expending the effort to try and measure it better and act on that - but that has an opportunity cost also. So you are suggesting incur a real cost just in case? I don’t buy it. The guy with the watch analogy only works if there is good reason to believe he’d be better off searching elsewhere. But we don’t appear to have that here....
- pandaman 8y agoI am not sure you checked out the link I've given. It's quite a substantial evidence that not hiring Koum and Acton might have costed FB somewhere around $19B if one were to believe WhatsApp was acquired to neutralize competition and not for its amazing revenue. Let's be generous and say the WhatsApp was a 10x unicorn so FB overpayed only 9B for it. Which makes 4.5B loss per false negative on each founder. If a false positive was, on average, 1M loss (which is an extremely generous in an organization such as FB in my recollection), it means you could have had 4000 false positives for each of these negatives and still come ahead. And, it brings us back to the Type I and II errors - it's always cheaper to make one, which has a limited downside than the unknown (potentially very high one). Typical example given is that while you are on the way to an expensive cruise you realize that you might have forgotten to turn off the stove. If you go back you might miss your 10K cruise. If you cary on, you might lose you 1M house. On average, people who miss cruise in such circumstances fare much better than ones, who risk their houses.
- ska 8y agoI know that story - but think it is enough of an outlier (regardless of how it went down) to basically be irrelevant to almost all hires. The idea that people are routinely filtering out great hires in their thousands in ways that come back to haunt them ... doesn’t seem plausible. I get what you guys are saying, there just doesn’t seem to be real evidence that is an issue nearly all cases. Whatsapp notwithstanding
- 8y ago