EBoard 03 (Section 1): Mental Models

Warning This class is being recorded.

Getting started (this will be our normal start-of-class sequence)

• Grab a card. The card will have a computer name and a location.
• Remember the name and location.
• Drop the card back in the jar.
• Navigate to the computer.
• If you arrive first, start the lab.
• When both partners arrive, introduce yourselves.

For the future: I’m happy to reserve a (somewhat random) seat at the front of the classroom for those who need a front seat as an adjustment or accommodation. Just let me know.

Approximate overview

• Administrative stuff; no attendance [10–15 min]
• Lab one [n min]
• Lab two [n min]

Administrivia

Introductory notes

• I’m still Sam (or SamR).
• Our mentors are still Ellie and Ella (or vice versa).
• I tend to respond faster to Direct Messages (Chat) on Teams than email.
• We’ll talk about Gradescope on Wednesday. (Our mentors will remind me if I do not.)
• We will be using a different implementation of Scheme than the other sections of 151.
• I will do my best to post a link to the Otter.ai transcript on Teams, in the recordings channel.
• Our class site is still under development. Let me know if you find things missing, including images.
• About five of you didn’t respond to the reading. Don’t forget!
• Only answer the double-dagger self checks.

Upcoming Token activities

Academic

• Convocation, Thursday, 11:00 a.m. President Harris.

Cultural

Peer

• Volleyball scrimmage today at 5:15 in Darby
• Volleyball game on Friday at 5:00 against Bethany and Dominca.
• Football a week from Saturday, 1pm, against Rippon.

Wellness

Upcoming work

• Intro survey and syllabus questions due tonight by 10:30 p.m.
• One reading for Wednesday; fill reading on Gradescope by Tuesday night.
• Lab writeup due before class on Friday.

Questions on the readings

Are we using VSCode w/Scamper or DrRacket?

Whoops. DrRacket.

Must there be exactly two arguments to an arithmetic operator?

Nope. You can have as many (or perhaps as few) as you want, at least for most operators.

You can write (+ 2 3 4 6)

> (* 2 3 4 6)
144
> (* (+ 2 3 4) (+ 5 6))
99
> (+ 5)
5
> (+)
0

Please go over basic building blocks.

You need to start somewhere in writing an algorithm. That is, you need to be able to assume that the computer knows how to do some things (e.g., add).

The data (I know what a number is) and operations (I know how to add) are the basic building blocks of most programming languages.

Why can’t I do the computing with images part?

You need a special library. Sorry about that. You should learn that today.

When you hit problems like that, please DM me.

Do we read lab instructions prior to class?

Please don’t.

Which questions do we answer on Gradescope?

Only the ones with the double daggers.

But you should answer the other ones to yourself.

What is the assignment called on Gradescope?

Reading assignments are usually called “Readings for class ##”

Lab assignments are usually called “Lab for class ##”

If you don’t see it, I probably forgot to post it. Chat me on Teams. Or email me.

Note: No late penalties for the first reading.

Debrief on Prior Class

We will do this as a Think/Pair/Share (or just TPS) activity.

• Think for a minute to yourself.
• Discuss the idea with your partner.
• Share with the broader classroom.

Getting students into card groups was somewhat chaotic. I intentionally don’t provide an algorithm, and it sometimes shows. What would be a better algorithm for getting card groups together?

• Divide into smaller groups (e.g., smaller numbers and larger number) and then divide again and again.
• Put one designated person with each card somewhere in the room and send everyone to meet that person.
• Scrap the cards altogether. Give everyone a pair of numbers that specify their coordinate in the room.
• Put your fingers in the air, in the air. Put your fingers in the

Lab 1: Setting up Linux

This lab appears in the Schedule. Each person will do this separately, with the other person helping.

In past years, some students have had to edit the launcher to use firefox instead of firefox-esr %u. I’m not sure why people end up with different launchers.

I apologize to those of you who could not get started because of issues with MathLAN. Those should be resolved by the end of the day.

Lab from Monday: Learning Scheme

• It’s generally a bad idea to skip ahead in the lab.
• Why doesn’t this work
• The origin of the short and long versions. My colleagues who first taught the course wrote the long versions (or at least the original versions of the long versions). When I started teaching, I decided you might do better with short instructions. But it’s a nice example of different ways of thinking about writing algorithms/instructions.
• I see that many of you have three screens (our main screen plus two laptops). Please do your work on the MathLAN workstation and just use your laptop for bringing up the lab/reference materials.
  • If I see you running DrRacket on your laptop, I may attempt to defenestrate aforementioned laptop.