4 ms·

The earlier classes are exactly the place where things like prior experience and level of interest can possibly explain bimodality. In which case bimodal grades

The earlier classes are exactly the place where things like prior experience and level of interest can possibly explain bimodality. In which case bimodal grades exist, but the conclusions you can draw from their existence are pretty mundane (e.g., turns out you do better if you had a programming class in high school... surprise!) and sufficiently varied that it'd be hard to come up with any compelling interpretation of the data. There's a survivor-ship bias in later courses. The extent of that bias can only be determined by looking at attrition rates. But it's far easier to predict and measure the major threats to validity for data in later courses. So, if I were interested in the question "Are some people just naturally better at CS than others", I would either focus on later courses and try to determine the extent of survivor bias, or else I would look holistically at the entire curriculum. But I definitely wouldn't give a lot of weight to 100-level courses.

taneq 10y ago
In my own experience, later courses (in computer science specifically) tend to erase the bimodal distribution because your ability to do science related to computing is almost orthogonal to your ability to actually build something with computers. Some of the people who graduated with honours alongside me could not code their way out of a paper bag if there was an exit_paper_bag() instruction.
Jtsummers 10y ago
> The earlier classes are exactly the place where things like prior experience and level of interest can possibly explain bimodality. I saw this a lot at GT. There, many students had to take the introductory programming course at the time (all engineering and sciences? circa 2000 if someone wants to help me remember). There was a great disparity between those of us who programmed in HS (or earlier) and those who didn't. What isn't clear is whether the poor grades were due to a lack of aptitude for the material, or a lack of skill on the faculty's part in presenting and educating, or a lack of interest or focus from those particular students (given it was their first and last CS course and they had to deal with the rest of the hell that was GT's first year).
- xapata 10y ago
  Some of my professors at GaTech complained that half the students just "couldn't learn" computing. I believed it at the time, but now I think it's that certain styles of coding are prone to mistakes when under stress -- such as when taking a test or on a deadline to submit an assignment. The classic example is the swap function. One professor asked us to code swap on every exam, even announcing he would in advance. Every exam, a significant portion of the students got it wrong. Because they couldn't memorize 4 lines? That's hard to believe. Easier to believe those 4 lines are so easy to remember that the student wrote them too quickly and moved on to the next question before noticing they'd written them out of order.
x1798DE 10y ago
But if binodality is really strong in early level classes for that reason, it sorta suggests that maybe you should split into a fast and slow track, letting the experienced people maybe do 2 semesters in one class. Then the students with no experience but raw talent don't just drop off because they are having trouble keeping up with peers who have been programming since they were 11.
- ghaff 10y ago
  My understanding is that some schools are experimenting with this. CS is unusual (though not unique; music is an obvious other example) in that there can be such a wide disparity in experience among otherwise equally bright/talented entering students. By contrast, no one expects an incoming Chemical Engineering freshman to know much in the way of chemistry or engineering beyond their couple semesters in high school. As someone with a fair bit of programming experience, but who doesn't really do it professionally, I can say that with one of the Intro to CS courses I took on edX, I would have been utterly and completely lost had I none or little programming experience.
- zardo 10y ago
  That would be a step in the right direction. But we should just walk all the way over to the solution. Education in all areas should have n-tracks, where n is the number of students.
- crispyambulance 10y ago
  That is a form of "mastery-based" learning. Basically, you group students according to ability and separately teach them each topic to the point of mastery before moving onto the next topic. The guy from the Khan academy talks about that (https://www.youtube.com/watch?v=LnVzug0mA2w https://www.youtube.com/watch?v=LnVzug0mA2w), although he suggests going even further-- individualizing each student. BTW, this is how the children of very wealthy parents often get to elite colleges in quite high numbers. The parents send them to private schools where student-teacher ratios can be as low as 5 (FIVE!). Under those circumstances, each student can get tracked very accurately according to their needs and aptitudes. It is a great way to learn, it works, but is also very expensive.
- 10y ago
MustardTiger 10y ago
>The earlier classes are exactly the place where things like prior experience and level of interest can possibly explain bimodality Ok? This is claiming bimodality doesn't exist, not trying to explain it.

taneq 10y ago

In my own experience, later courses (in computer science specifically) tend to erase the bimodal distribution because your ability to do science related to computing is almost orthogonal to your ability to actually build something with computers. Some of the people who graduated with honours alongside me could not code their way out of a paper bag if there was an exit_paper_bag() instruction.

Jtsummers 10y ago

> The earlier classes are exactly the place where things like prior experience and level of interest can possibly explain bimodality. I saw this a lot at GT. There, many students had to take the introductory programming course at the time (all engineering and sciences? circa 2000 if someone wants to help me remember). There was a great disparity between those of us who programmed in HS (or earlier) and those who didn't. What isn't clear is whether the poor grades were due to a lack of aptitude for the material, or a lack of skill on the faculty's part in presenting and educating, or a lack of interest or focus from those particular students (given it was their first and last CS course and they had to deal with the rest of the hell that was GT's first year).

xapata 10y ago
Some of my professors at GaTech complained that half the students just "couldn't learn" computing. I believed it at the time, but now I think it's that certain styles of coding are prone to mistakes when under stress -- such as when taking a test or on a deadline to submit an assignment. The classic example is the swap function. One professor asked us to code swap on every exam, even announcing he would in advance. Every exam, a significant portion of the students got it wrong. Because they couldn't memorize 4 lines? That's hard to believe. Easier to believe those 4 lines are so easy to remember that the student wrote them too quickly and moved on to the next question before noticing they'd written them out of order.

x1798DE 10y ago

But if binodality is really strong in early level classes for that reason, it sorta suggests that maybe you should split into a fast and slow track, letting the experienced people maybe do 2 semesters in one class. Then the students with no experience but raw talent don't just drop off because they are having trouble keeping up with peers who have been programming since they were 11.

ghaff 10y ago
My understanding is that some schools are experimenting with this. CS is unusual (though not unique; music is an obvious other example) in that there can be such a wide disparity in experience among otherwise equally bright/talented entering students. By contrast, no one expects an incoming Chemical Engineering freshman to know much in the way of chemistry or engineering beyond their couple semesters in high school. As someone with a fair bit of programming experience, but who doesn't really do it professionally, I can say that with one of the Intro to CS courses I took on edX, I would have been utterly and completely lost had I none or little programming experience.
zardo 10y ago
That would be a step in the right direction. But we should just walk all the way over to the solution. Education in all areas should have n-tracks, where n is the number of students.
crispyambulance 10y ago
That is a form of "mastery-based" learning. Basically, you group students according to ability and separately teach them each topic to the point of mastery before moving onto the next topic. The guy from the Khan academy talks about that (https://www.youtube.com/watch?v=LnVzug0mA2w https://www.youtube.com/watch?v=LnVzug0mA2w), although he suggests going even further-- individualizing each student. BTW, this is how the children of very wealthy parents often get to elite colleges in quite high numbers. The parents send them to private schools where student-teacher ratios can be as low as 5 (FIVE!). Under those circumstances, each student can get tracked very accurately according to their needs and aptitudes. It is a great way to learn, it works, but is also very expensive.
10y ago

MustardTiger 10y ago

>The earlier classes are exactly the place where things like prior experience and level of interest can possibly explain bimodality Ok? This is claiming bimodality doesn't exist, not trying to explain it.