Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Khan Academy: Computer Science

khanacademy.org

Post reply on HN
Print view View original

161–170 of 188 posts

Re: Khan Academy: Computer Science

#161

Post by teach »

sethg wrote: post #155
teach wrote: post #129

Earlier quoted context omitted.

I agree. I don't get to choose whether or not I teach Java; that's determined by the state. However, in my class, we write our first working program on the first day of coding. We install the JDK, do a basic DOS primer, type in our first program (in Notepad), and compile and run it on the command line in a single 90-minute period, like the 3rd day of class. Getting to the "bang" as quickly as possible is HUGELY impor…

Do the students move on to using an IDE? I realize that Eclipse or Visual Studio comes with a lot of overhead and you can easily spend a whole semester getting bogged down in all the options, but I would think that an editor with syntax highlighting and parenthesis matching would make a big difference.

Yes, I only make them do the first ten assignments in Notepad and a command-line compiler. Then we switch to JCreator, which is a pretty unremarkable IDE, but it does have syntax highlighting and a few other niceties that make it a much more efficient code editor.

Re: Khan Academy: Computer Science

#162

Post by teach »

Legion wrote: post #157
teach wrote: post #83

Earlier quoted context omitted.

How to use a compiler. Basic shell of a Java program. That statements occur in a sequence. Practice with getting details right. Mathematical expressions. What variables are, and how assignments to expressions differ from formulas (in Excel, say). If statements and conditions. The concept of "incrementing" a variable or accumulators in general. Loops in general. See for yourself: http://cs.leanderisd.org/current/cs1/a…

Heh. From the way I've heard some parents talk about Leander ISD, I would have figured the kids would have for loops down by 4th grade. :)

I wish we could start teaching real programming in middle school at least. I think just variables, if statements and some sort of looping construct ought to be mandatory in education.

Re: Khan Academy: Computer Science

#163

Post by teach »

flexd wrote: post #94
teach wrote: post #83

Earlier quoted context omitted.

How to use a compiler. Basic shell of a Java program. That statements occur in a sequence. Practice with getting details right. Mathematical expressions. What variables are, and how assignments to expressions differ from formulas (in Excel, say). If statements and conditions. The concept of "incrementing" a variable or accumulators in general. Loops in general. See for yourself: http://cs.leanderisd.org/current/cs1/a…

Your CS curriculum is much better than my schools! I just started my first year of Computer Engineering and the Java course so far is horrible compared to this. I'm a bit disappointed to be honest. I am very glad I already have been coding for years because our teacher and the planned curriculum seems to confuse people even more. I think I will refer some people to your assignments, if that's okay? Hopefully someone…

I'd be honored for you to point some folks at my assignments, although please only share the link one-on-one: a few of the assignments on there (the ones with an author of "Stacey Armstrong") are part of a curriculum that our district pays to license. Technically I could get in trouble for having his assignments on a public website without permission.

Re: Khan Academy: Computer Science

#164

Post by wattjustin »

nextparadigms wrote: post #147
teach wrote: post #69

High school CS teacher here. I really hate taking shots at Khan Academy, because I love what they do and his other videos have really helped a lot of my students in chemistry, economics, etc. However, he's moving through the material MUCH more quickly than I've ever been able to do as a teacher. And I get nearly 5 hours a week of face time with my students. For example, his third lecture is on for loops. My students,…

I think Khan is moving too fast through them, too. Have you tried these: http://www.thenewboston.com/?cat=40&pOpen=tutorial

I have been using these to learn programming (Python specifically, which is my first language). I am curious as to what others think of these tutorials if they've seen them before?

Re: Khan Academy: Computer Science

#165

Post by teach »

garbledNonsense wrote: post #112
teach wrote: post #83

Earlier quoted context omitted.

How to use a compiler. Basic shell of a Java program. That statements occur in a sequence. Practice with getting details right. Mathematical expressions. What variables are, and how assignments to expressions differ from formulas (in Excel, say). If statements and conditions. The concept of "incrementing" a variable or accumulators in general. Loops in general. See for yourself: http://cs.leanderisd.org/current/cs1/a…

Initially, I thought this sounded ridiculous. But when I look carefully at what you've done, I'm impressed by your thoroughness. I think you have an excellent course for weak-to-average students. I do wonder if your most able students might appreciate more opportunity to "play" and be creative, but in all honesty, they just need to stick with it into the Project Euler stuff at the end. Is this a whole-year course?

First, thanks for the kind words. This curriculum has been relentlessly pivoted and iterated based on feedback from over a thousand real students for the past fifteen years.

Yes, this is a whole year (36 weeks).

The material you're seeing is only the intro material, though. I teach three other courses, including video game development. The faster students are encouraged to skip assignments if they're coding something they already understand, and they get bonus points if they do something creative with an existing assignment.

I've tried to optimize for the normal case: the weak-to-average student. The great ones however, don't need much help from me to learn a ton very quickly.

Re: Khan Academy: Computer Science

#166

Post by teach »

fjw wrote: post #103
teach wrote: post #83

Earlier quoted context omitted.

How to use a compiler. Basic shell of a Java program. That statements occur in a sequence. Practice with getting details right. Mathematical expressions. What variables are, and how assignments to expressions differ from formulas (in Excel, say). If statements and conditions. The concept of "incrementing" a variable or accumulators in general. Loops in general. See for yourself: http://cs.leanderisd.org/current/cs1/a…

Interesting schedule. My school's AP Comp Sci A class (also teaches Java) is designed for people who are completely new to programming, but we are introduced to loops fairly early. After first being introduced to the different variable types, mathematical expressions, and how to read user input, the students jump directly into boolean, if, switch, and then the for/while/do-while loops.

How many kids take the class? How many do well?

I have 75 kids in three sections, and I'd have 100 kids in four sections if they'd open up a fourth section. And all of my students except maybe the bottom 5-10% are moving confidently through the material at their own pace.

I'll bet your school either has 1) a lot fewer students 2) a much more hand-picked set of kids, or 3) is leaving a much higher percentage of kids behind, who are either lost or cheating.

Re: Khan Academy: Computer Science

#167

Post by teach »

sethg wrote: post #109
teach wrote: post #69

High school CS teacher here. I really hate taking shots at Khan Academy, because I love what they do and his other videos have really helped a lot of my students in chemistry, economics, etc. However, he's moving through the material MUCH more quickly than I've ever been able to do as a teacher. And I get nearly 5 hours a week of face time with my students. For example, his third lecture is on for loops. My students,…

I’ve been programming professionally for over ten years, and when I have to look at Java code that other professionals have written, I am constantly irritated by how the actual point of the code is buried in… mquader’s “OO ceremony” label elsethread is an apt phrase, although “Java ceremony” might be more fair. It wouldn’t surprise me at all if high-school students learning Java as their first language got confused m…

I'd bet $100 that the AP exam will switch to Python within ten years. And probably not much more than 5.

(No sooner than that though, or they'd have to have announced it already; major changes in public education need a LOT of lead time.)

However, I'll disagree that Python would be that much easier than Java for a beginner's course. It's lower-friction, to be sure, but the VAST majority of student difficulties are with precise logical thinking, not with the syntax.

Decomposing a problem into discrete, correctly-ordered steps is the core difficulty. This is unrelated to syntax.

Re: Khan Academy: Computer Science

#168

Post by tel »

dpritchett wrote: post #160
tel wrote: post #106

Earlier quoted context omitted.

Assignment isn't idiomatic in functional programming.

The functional programming is a side effect of the desire to teach computer science in a low-friction way. It's nice to not have to also teach Java along with your CS concepts. I know that when I teach myself anything it's best to focus on one new concept at a time. Scheme's light weight allows all but the CS concepts to fall away from the new coder's consideration.

The functional programming is a side effect of the desire to teach computer science in a low-friction way.

And why not code in a low-friction way even when not being taught? I wasn't intending to defend FP, but I think it's silly to think of assignment as a fundamental part of CS or the art of coding. It's just one tool.

Re: Khan Academy: Computer Science

#169

Post by teach »

n2dasun wrote: post #158
teach wrote: post #83

Earlier quoted context omitted.

How to use a compiler. Basic shell of a Java program. That statements occur in a sequence. Practice with getting details right. Mathematical expressions. What variables are, and how assignments to expressions differ from formulas (in Excel, say). If statements and conditions. The concept of "incrementing" a variable or accumulators in general. Loops in general. See for yourself: http://cs.leanderisd.org/current/cs1/a…

Thanks for posting that. I love how thorough and paced it is. I'm definitely bookmarking that link, as well as /cs2/assignments.html

You're welcome. Happy coding!

Re: Khan Academy: Computer Science

#170

Post by teach »

jbermudes wrote: post #114
teach wrote: post #69

High school CS teacher here. I really hate taking shots at Khan Academy, because I love what they do and his other videos have really helped a lot of my students in chemistry, economics, etc. However, he's moving through the material MUCH more quickly than I've ever been able to do as a teacher. And I get nearly 5 hours a week of face time with my students. For example, his third lecture is on for loops. My students,…

If I may ask, what is your credential in? There seems to be quite a mess in regards to how to get in to the field since there doesn't seem to be a computer science credential, and coming in with a math credential will almost certainly get you assigned to teaching math classes and math teachers are always in demand.

I've got a bachelor's in CS, and teaching certificates in both mathematics and "computer information systems", which was what the CS certificate was called 15 years ago.

There is now a teaching certificate in just "Computer Science", although it wasn't offered in Texas for a few years while they were switching from one to the other.

Other states vary widely, I'm sure.

Post reply on HN