category theory

[rwx]

If folks, especially folks with a library science, it, or software engineering background, could check out this presentation on category theory (PDF) and tell me how interpretable they find it, it would be greatly appreciated.

Comments

[kbuxton.livejournal.com]

I got about 4 slides in and gave up.

[stoneself.livejournal.com]

software background me:
- many of the slides have too much text
- when introducing new terms it's helpful to say (this morphism thing is like xxxx from yyyy)
- that slide about which graphy things are valid categories... to busy
-- better to say. this is a valid category... this is not because
-- also skip "for the expert" question. address your audience... they are beginners.
- i'd use at least one concrete example category over and over and over for each new bit of terminology you add
-- there are too many examples to keep track of (numbers, sets, friends, even, odd, temperatures, etc)
- slide 19 looks very very important... but too dense to understand and lacks concrete examples. maybe should be broken into more slides.
- i'd use a more general pseudo code than lisp
- slide 39 totally making my eyes cross
- dang this thing is long... you going to do this in 3 hours?

i'd have to say my eyes would glaze over around slide 12 if i weren't getting graded on this. and if i were being graded on this, may around slide 18.

cog sci me:
now i have to poke around at this to see if works in any interesting way with cognitive categories

[rwx.livejournal.com]

yeah, i didn't write this, in case that wasn't clear... it was more to see if folks can parse the information contained herein because i'm writing something similar, not whether it's well-written (which it isn't, but it appears to be servicableish for its original audiences.)

[stoneself.livejournal.com]

in that case, i can parse it, but it takes more effort than set by the expectations (beginner) and maybe more effort than it's worth.

the only reason i worked as hard to read it as i did was that you asked. all it really made me want to do was find a better source.

as a lecture it sucks: too fiddly, too abstract, and not for "beginners" half the time.

as reading material it sucks: not concrete enough, i had to read the motivation stuff more than once to figure out why i'd want to do this (and i'm not convinced), and after that i really struggled to even bother getting a surface gloss (i was losing interest and getting annoyed)

[rwx.livejournal.com]

thanks, if i ever see you in person i owe you a drink or something.

[kodi]

I thought I had a software engineering background, but since I don't "(Recall...)" either of the slides I'm supposed to, I assume "software engineering background" refers to people who study software engineering, not those who perform it.

[antje23.livejournal.com]

well, right out of the starting gate, slide 4 should be before slide 3.

I'll continue reading...

[yong-mi.livejournal.com]

As somebody with all of the backgrounds you mentioned, Slide 5 (and henceforth) made me roll my eyes. I'd never heard of category theory before. This person set up my expectation that he would explain it even to novices. Hello?
Like stoneself sez, it needs a concrete example. Or several.

[rwx.livejournal.com]

yeah, it's a problem. i personally find it easy to read, but i had functional composition in 8th grade maths, so it needed to be tried out on a general audience.

[rwx.livejournal.com]

the uuuber point of this is that it ties into how much explanation is needed for something i'm writing.

[madcap-allie.livejournal.com]

Slide 19 made me smack my forehead, and now it hurts. What, software modularity is good and useful?? Gee, that's fresh and exciting news.
Until then it had my attention.
After that I started skimming.

The geometric-example of isomorphism slide... First off, they should have labeled the pairs of polygons, and secondly, it's a boring example, anyway.

The "motvation" slides shouldn't have such a huge gap between them. Also, I'd put CS before Math, and the state-machine model before the algebra model, and...

Perhaps a slide at the beginning: "Category Theory is a method for nani-nani that developed out of nani-nani to address the needs of information scientists to nani-nani..." And then the pretty pictures.

...I'm now printing out a copy for my software engineer / AMATH coworker. You just helped me totally make his day. Mwah!

[rwx.livejournal.com]

i agree entirely, except i think that 'nani-nani' should be left in.

[anavolena.livejournal.com]

i gave up actually trying to parse at page 4, and gave up even looking around page 8.

[brassratgirl.livejournal.com]

as someone with absolutely zero knowledge of "category theory" (I'll categorize your theory!):

I sort of get where he's going, but the math is over my head (like many liberal arts majors [and librarians], I'm near math-illiterate, and he's assuming conversational set theory).

- slide 5 is a bitch; should define things in words as well as maths (morphisms?)

- slide 6,7,8 should come after the examples

-12 and 18 should come even before this

- he should spend more time on software engineering usage, it's interesting & passed over

- the outline slides: good idea, dorky implementation

- 29 could be explained better

in sum, it looks like a nice little piece of math, but this is explanation is much too difficult for me to draw any kind of useful corrolary to classification theory, which I get the sense is what you're getting at.

Bear in mind I am used to skimming incomprehensible things, getting the topic & making some sense out of them, and then moving on (from buying math & cs books, most of which are well over my head). I didn't actually spend the time to attempt to work any of the examples, actually understand the logic, etc.

Also, everything stoneself said.

Also, (as it should be!) the first few sections of the Wikipedia article are a happy surprise in being a relatively comprehensible introduction to the topic, +100 better than this presentation.
http://en.wikipedia.org/wiki/Category_theory
However, the article skips the "applications" bit which is the interesting part of the presentation.

For everyone who gets interested in this topic now, there's also a couple citations to "important publications in category theory":
http://en.wikipedia.org/wiki/List_of_publications_in_mathematics#Category_theory