There are three big problems with weeder courses. The first is that reality is a graph, not a hierarchy. The common assumption underlying the argument in favor of weeder courses is that if those courses cannot be passed, nothing else will make sense. Weeder courses are only in base-level courses without which nothing further can be gained.
This assumption is false in general. Of course for localized special cases it holds: one needs to know addition before multiplication and multiplication before exponentiation and exponentiation before Knuth's up-arrows. But one does not need to deeply (or in some instances not even shallowly) understand the differential or the integral calculi before one can understand fuzzy logic, discrete probability, frequency, combinatorial game theory, number theory, or how to feed instructions to a computer. (How to feed instructions that calculate via differential equations on the other hand... But you don't need to be good at it; the Deep Blue programmers weren't better than Kasparov at Chess, they just needed to understand the basics of how Chess worked.)
Since this assumption is false, the notion of "pre-requisite" which often accompanies weeder courses falls on its face for more instances than are likely justified. Advice for schools: get rid of "pre-requisites" and embrace the opportunity of 1) more money from students who fail and re-take when they're ready 2) personalized student consulting with their academic advisor, who should notice red flags and consult with the student to question whether their confidence in themselves isn't misplaced.
The second big problem is that a plucked weed may have been a flower that hasn't bloomed yet. If you don't present at least one serving of the very exciting possibilities in the field in an intro class, you're going to leave a lot of buds behind who decide they want to do something more interesting when in fact they would have been most interested in the first field if only they had seen its potential. If the weeder course is unpleasant, you setup the bud to expect more unpleasantness and create it for themselves. If the weeder course makes them fail, they are prevented from taking any other courses in that field they might actually be good at because they don't use the "ever-present fundamentals" that tripped them up in the weeder course. If the weeder course makes them fail, but they're a late-bloomer and in another year with a more basic instruction to their existing experience they would have tackled the "weeder" course with ease, they're prevented from an alternate path because the root is mandatory.
This problem is largely solved by having two or more tracks for a field. Computer Science is notoriously lacking in this department. There is One and only One. And it's slightly different for every school. (Though all the mediocre schools follow a similar pattern at least.)
The third big problem is that the weeder courses become sleeping courses for the non-weeds. They promote "intellectually lazy" teaching and learning. Take your stereotypical nerd who breezed through high school. They get to college and they breeze through Freshman year "weeder" courses. At this point some will conclude that college is a waste of time and go on to do more important and interesting things. Others will be happy to not worry about a job and breeze through the courses while working on whatever interests and challenges them personally. Others will hit their peak in any of the following years, realize they've developed no strategies for dealing with hard work that requires effort, and give up. Others won't hit their peak but will get incredibly lazy and start down a path of mediocrity that is as seductive and hard to reverse and balance as the path of the Dark Side; they will graduate and get an intellectually unsatisfying job but they will soon forget if they haven't already what it means to be intellectually gratified. Others will hate both the breezy work and the useless-but-time-consuming (and "hard", "takes-effort") busy-work; they will burnout on school, and suddenly be unable to make themselves do something they normally would have breezed through or else would have used the appropriate method for solving a hard or effort-taking problem that they've encountered before in real challenges.
The union of these "others" represents a set of very dissatisfied students many of whom will just decide at some point to not finish the program. For some of these students, there are solutions. Having a "beginners", "some experience", and "we expect you to take mostly graduate courses" track would help a lot, though the last one is hard to distinguish between an actual Master's program so the problem is more about opening up the Master's program to people without undergrad degrees. Having a "do what the fuck you want" track would also help some of these students but is not really feasible funding-wise. But overall, if we ignore those who reach their peak early on and those who become vegetables due to laziness, we're talking about a group of talented individuals who are going to be frustrated in some form or another by the very essence of academia. (Note that people who like this sort of thing and aim to become professors are not part of this conjunction.) You can't help these individuals within the academic framework as it currently exists. Give them some real work to do or find them a Mentor.
With these three problems I think weeder courses have no benefit to anyone. They don't help the beginners, they don't help the middle ground who just do "alright" with the weeder courses but would benefit from not being jerked around, they don't help the budding flowers who will never experience other parts of the field, and they especially don't help the ones with too much experience already. (This last group is royally screwed in courses that aren't even their core field too because they are probably used to learning on their own and when faced with something they don't understand that they want/need to understand they go and learn it at once and don't stop until they're satisfied; while it might take months to learn, they don't sit in a lecture room for a few hours a couple times a week to do it.)
Posted on 2012-05-16 by Jach