Hacker News new | ask | show | jobs
by jdiff 847 days ago
I'm not the person you asked, but I'm not sure I understand your question and I'd like to. It whiffed multiple common softballs, to the point it brings into question the claims made about its performance. What reasoning is there to trust it?
2 comments

It had 3 failures. How is that a sign it's untrustworthy? I'm sure all alternatives have more than 3 failures. You might be making assumptions about the distribution of successes and failures (GP didn't say how many files they tested to find those 3) or how "soft" they were. In an extreme case, they might even have been crafted adversarial examples. But even if not, they might have features that really do look more like some other file type from the point of view of the classifier even if it's not easily apparent to a human. Being strictly superior to a competent human is a pretty high bar to set.
> or how "soft" they were.

From the comment: It identified some simple HTML files (html, head, title, body, p tags and not much else) as "MS Visual Basic source (VBA)", "ASP source (code)", and "Generic text document" where the `file` utility correctly identified all such examples as "HTML document text".

That's pretty soft. Nothing "adversarial" claimed either.

> Being strictly superior to a competent human is a pretty high bar to set.

The bar is the file utility.

Those are only soft to a human. I looked at a couple and I picked them correctly but I don't know what details the classifier was seeing which I was blind to. Not to say it was correct, just that we can't call them soft just because they're short and easy for a human.

> The bar is the file utility.

It has higher accuracy than that. You would reject it just because the failures are different even though they're less?

Yes. Unpredictable failures are significantly worse than predictable ones. If file messes up, it's because it decided a ZIP-based document was a generic ZIP file. If Magika messes up, it's entirely random. I can work around file's failure modes, especially if it's one I work with often. Magika's failure modes strike at random and are not possible to anticipate. File also bails out when it doesn't know, a very common failure mode in Magika is that it confidently returns a random answer when it wasn't trained on a file type.
Your original statement was that having a couple of failures brings into question its claims about performance. It doesn't because it doesn't claim such high performance. 99.31% is lower than perhaps 997 out of 1000 or whatever the GP tested. Of course having unpredictable failures is a worry but it's a different worry.
They uploaded 3 sample files for the authors, there were more failures than that, and the failures that GP and others have experienced are of a less tolerable nature. This is the point I was making, that the value added by classifying files with no rigid structure is offset heavily by its unpredictable shortcomings and difficult-to-detect failure modes.

If you have a point of your own to make I'd prefer you jump to it. Nitpicking baseless assumptions like how many files the evil GP had to sift through in order to breathlessly bring us 3 bad eggs is not something I find worthwhile.

> It whiffed multiple common softballs

I must have missed this in the article. Where was this?

...It's in the comment you were responding to. Directly above the section you quoted.
I understand that, but it wasn't clear to me where those examples came from.
It's pretty obvious from the whole comment that they're his own experience. Are you going anywhere with this or are you just saying things?