More Debate, Please!

“… there are many issues in computing that inspire differing
opinions. We would be better off highlighting the differences
rather than pretending they do not exist”
–Moshe Y. Vardi

In an article entitled “More Debate, Please!”, in the January, 2010 issue of Communications of the ACM, Moshe Y. Vardi, editor-in-chief of Communications, writes:

‘Vigorous debate, I believe, exposes all sides of an issue—their strengths and weaknesses. It helps us reach more knowledgeable conclusions. To quote Benjamin Franklin: “When Truth and Error have fair play, the former is always an overmatch for the latter.”’[1]

Vardi goes on to say that as he solicited ideas for the 2008 relaunch of Communications, he was frequently told to keep controversial topics front and center. “Let blood spill over the pages of Communications,” a member of a focus group colorfully urged [1].

When attempting to publish my doctoral research in evolutionary computation journals, I found the sentiments expressed by Vardi to be in short supply. The reviewers seemed much more invested in not rocking the boat than in fostering a climate in which prevailing assumptions can be challenged, and alternate ideas expressed transparently. They seemed, in short, to be inured to the poverty of the field’s foundations, and, for the most part, had little tolerance for someone with a bone to pick with the status quo. “Fall in line, or have your work be rejected,” was the overarching message.

One way this unfortunate state of affairs may be addressed is through the institution of a forum like the Point/Counterpoint section introduced to Communications by Vardi in 2008—a forum where the various controversies that mark our field are periodically featured, and the different sides of each controversy given, as Benjamin Franklin put it, “fair play”. There are several contentious topics in EC. Tapped correctly, many of  these topics can be powerful vehicles for learning—not just about the workings of evolutionary algorithms, but, also, about the workings of a vibrant intellectual community. Right now, instead of vigorous, open, ongoing debates in the EC literature, uneasy truces prevail. The community, by and large, steps around the the really big points of contention. Researchers talk past each other to niche audiences. And, if my experience is anything to go by, new lines of criticism, and new modes of analysis are hastily dismissed.

In the absence of a written record of ongoing controversies, new entrants to the field will not have access to the various positions involved. Pressed for time, and confronting the reality of “publish or perish”, most will fall back on the opinions and practices of their advisors. It doesn’t take much to see that in an environment like this, opportunities for learning and advancement will frequently be missed.

A forum for open, ongoing, collegial debate would  bring awareness, and transparency to the controversies in our field. It would also (one hopes) inculcate a more welcoming attitude toward alternate approaches, conclusions, and critiques.

Two topics for debate:

EC Theory and First Hitting Time:  Is it problematic that so much contemporary theoretical  work in EC focuses on “first hitting time”, i.e., the number of fitness evaluations required to find a global optimum? Do we look at first hitting time only because there currently isn’t a well developed, and generally accepted theoretical framework for examining adaptation (the generation of fitter points over time)? If so, isn’t the study of first hitting time a lot  like the proverbial search for one’s house keys under the light of a street lamp just because it happens to be dark in one’s house?

The Building Block Hypothesis: Can the building block hypothesis be reconciled with the widely reported utility of uniform crossover? If yes, how? If no, can we—more to the point, should we—be comfortable with this knowledge given the considerable influence of the building block hypothesis on contemporary evolutionary computation research?

What other topics have been under-addressed in the evolutionary computation literature? Leave a comment with your opinion, or a link to your own blog post.

[1] Moshe Y. Vardi. More debate please!, In Communications of the ACM 53(1):5, 2010

More Debate, Please!