Wednesday, October 28, 2009

Clustering interlude: Time series

In the absence of an actual post on clustering, I encourage all of you to go and read Sorelle's (or should I say ***SORELLE***'s) post on time series clustering.

Monday, October 19, 2009


(while I wait for actual inspiration to strike)

I just acquired an invite to Google Wave (thanks to John Moeller), and have been finding it quite intriguing (note: you can't "get" Google Wave unless you're invited, and no, I don't have any invites to give out).

Google Wave is a mysterious combination of email, chat, wikis and browser extensions that's hard to describe - you can read descriptions of it all over the web, but unless you are able to get in and start playing, it's like trying to buy wine based on text descriptions of the taste.

So far I've used it to:
  • discuss an outline for next semester's seminar with my students (Topics in Graph Algorithms, for those curious)
  • Start working with a collaborator on an outline for a tutorial we want to do
  • set up administrative struts for our research group svn server (I've started using svn for writing papers - it's an amazing experience - more on that some other time)
By far the coolest feature of Wave for me is that you can include a LaTeX extension into any "wave"or conversation, and it automatically converts things between $$...$$ marks into latex, which makes me hopeful that it will be useful for more substantive discussions (since I often wish I had such capabilities in Skype/Google chat)

Although the preview is painfully slow, and is crippled in various ways, the potential is clearly there, and as more people get on it, it will only start getting more effective. I'm looking forward to it.

Monday, October 12, 2009

On the virtue of NOT working on a problem

Semester has hit with a vengeance, and while I've been busy (among other things) with this and this, my clustering series has gone on temporary hiatus, hopefully to return shortly.

In all the pages and pages of advice given to grad students, postdocs, and starting faculty, I think one item tends to get left by the wayside, or at least is not explicitly stated.
You always underestimate the time spent managing a project from start to finish.
What I mean is this: problems (at least in theoryCS) are easy to state, and fun to work on. Sometimes they take a while to crack, and sometimes they give up their secrets easily. But the time you spend on any given project is much more than the actual time spent thinking about it. There's
  • Writing up the first few drafts
  • Iterating to get a polished submission version
  • (...this step repeats until the paper is accepted)
  • Preparing the final (often very cramped) version
  • Making slides for the talk/talks you'll be giving
  • Preparing a full/journal/arxiv version, which often involves simplifying, rewriting, reproving, adding new references, etc etc.
  • Submitting to a journal, and waiting endlessly for updates on its status.
  • Addressing reviewer concerns, and resubmitting
  • And finally, getting it into print.
The few-months thrill of actually thinking about the problem and solving it ends up being a multi-year odyssey filled with many fallow periods punctuated by bursts of activity.

It's not so much the time involved - papers tend to time-multiplex quite well so you're usually in different phases of the above sequence for different papers.

It's more a matter of motivation. I don't think I'm the only person who feels this, but once I have some nice results, and especially if there isn't follow-on work to be done, I get bored with a paper. Having to deal with it for months and months afterwards is then as excruciating as killing off zombies that keep coming back (not to mention what happens if it keeps getting rejected).

So be careful when you choose a project: make sure it can last through at least a few papers, or you'll be spending a lot of time cursing yourself for the time you spend.

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