This site

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If you're a student, please log in, so you can get the most from this page.

Lesson contents

This site is the textbook for your class. It also lets you upload your exercise submissions, get feedback, and other things. Here's how you use it.

Work through the lesson tree

The lesson tree is your table of contents for the course.

Lesson tree

Start at the top, and keep going until you get to the end.

Each page is a lesson. Lessons are mostly text and images, with exercises and questions embedded in them. There's often an exercise to submit at the bottom of each lesson.

Work on lessons from top to bottom

Don't skip to the bottom, find the exercise, and work back to the top. The exercise will be harder, since you won't know what you need to do.

Start at the top of each lesson, and work down.

Don't skip the More buttons

The More buttons break lessons into chunks. They reduce the load on your brain.

The More buttons have an arrow, with a "Show all" option.

More button

Click it, the More buttons vanish, and you can see the entire.

Don't use "Show all" the first time you read a lesson. "Show all" is for when you've already read a lesson, and are coming back to find something to review, or code to cut-and-paste.

But, the first time you read a lesson, use the More buttons, one at a time. It's easier on your skull meat.

Do exercises when you find them in lessons

You can get to exercises in a few different ways, like through the Exercises link in the main menu's List option. That's not normally what you want to do, though.

Exercises are embedded in lessons. Do exercises as you come across them, when you're reading the lessons.


What are the other methods for?

They're for convenience when you're looking for feedback, checking your progress, or finding an exercise you did, so you can copy some of its code. However, when you want to work on new material, just start reading the next lesson.

Work through lessons, not exercises

Answer the embedded questions

You'll find questions, like this:


Answer them.

The questions are not there to test you. Instead, they remind your brain of related things you've already learned. It helps you learn efficiently, by tying what you're about to read, to what you already know. Efficient is Good.

When you don't understand something...

  • Read it again more slowly. Quiz yourself on each step.
  • Ask people to explain it to you, in our Gather.Town space. <- This is a good one.
  • Ask Kieran.
  • Ask the interwebs.

The last one is tricky. Many of the answers on the 'net will use tech we don't use in the course. Could be old, could be too much programming.

Let's try to help each other. If you find something good on the 'net, please click the Suggestion button, and share.

Your account

You need an account to submit exercises, and get feedback. Kieran will make an account for you, if you're in one of his official courses. You'll get an email about it. If you don't have an account (maybe you added the course late, for example), contact Kieran at

(If you're not in an official OU course, and want an account, contact Kieran.)

There's a login link in the main menu. When you've logged in, you'll see a "Your stuff" entry, with items like:

Your stuff

This is where you can see information specific to you. If someone else uses your computer, don't forget to log out.

Messing with your account

Your account has basic information, like your name, email, and maybe a photo. You can change the information with Your stuff | Account. That "|" means clicking "Your stuff" in the main menu, then clicking "Account".

Click Your stuff | Account, and you'll see something like:


There are two tabs, View and Edit. The View tab shows you account information. Click the Edit tab to change the information. That's where you'll change your password, for example.

You'll need to type your current password, and your new password (twice).

Changing your password

Don't forget to click the Save button at the bottom of the page.

Change your password

You should change your password now. That's Your stuff | Account | Edit.


Right-click (or long-press on a touch device) on the Account link, and it will show a menu that lets you open the link in a new browser tab. It's a good way to do something, without losing your place.


What if I forget my password?

No trubba. If you forget your password, there's a "Reset your password" link on the login form. It will send you an email with a reset link. If you don't get the email, check your spam folder.


Your instructor won't have access to your password, so try the reset link first. Remember, check your spam folder.

Turn on JavaScript and cookies for this site

This site uses JavaScript and cookies to keep you logged in, make the lesson tree work, and other stuff. Please let this site do its thing, or it will be very hard to use. The site doesn't try to do Evil Things with JS or cookies


There's a Suggestion button (when you're logged in). See it?

If you find a mistake, even a missing word or some such, please use the suggestion button.

Another thing. Kieran made this site. He knows this stuff so well, he's forgotten what it's like to learn it. Things that are problems for you won't even occur to him. That's called the "expert's blind spot."

If an explanation confuses you, most likely there's a problem with the explanation, not you. And other people are probably confused, too. So, please suggest away!

If you've read this far, please use the suggestion button to tell Kieran a joke. He'd like to see how many people get down to here.

Jokes people have sent:

From Keegan:

Dog 1: Humans always say to chase your dreams. But how do we do that? We can't fetch them, and they're not squirrels.

Dog 2: It's really easy. I do it all the time.

Dog 1: Really? How?

Dog 2: (Turns around a few times on a cushion, curls up, and falls asleep.)

Dog 1: . . . That's brilliant!

From David:

When women reach a certain age, they start accumulating dogs. This is known as manypaws.

From Mathew:

How are a dog and a marine biologist alike?

One wags a tail and the other tags a whale.

From Ally:

Why should you never fight a dinosaur?

You'll get Jurass-kicked!

We still need to talk about how you submit exercises. That's the next lesson.