EBoard 05: Mental Models (Section 1)
Warning! You are being recorded (and transcribed) (provided the technology
is working correctly).
You should know the start-of-class algorithm
Approximate overview
- Administration
- Quiz notes
- Lab
Administrative stuff
Introductory Notes
- Please remember to return your blue cards to jar immediately after
determining where you are.
- During class, please work on our workstations, not your laptops.
- Congratulations to our football team for their season-opening victory!
- Quizzes were returned on Gradescope.
Upcoming activities
Scholarly
- Thursday, 10 September 2026, 11:00 a.m.–noon, JRC 101.
Scholar’s Convocation: Ruth Feingold
- Thursday, 10 September 2026, 4:00–5:00 p.m., JRC 101.
The Department of Revenge (NY Times Reporter; four-time Pulitzer winner)
- Thursday, 10 September 2026, 4:15–5:00 p.m., Science 3821.
Study Away for CS Majors
- Refreshments in the CS commons at 4:00 p.m.
Artistic/Cultural
- Saturday, 12 September 2026, 8:00 p.m., Gardner.
The Spine Stealers and Babehoven.
Multicultural
- Friday, 11 September 2026, 4:00–6:00 p.m., Ward Field.
DEI Kickback.
- Friday, 11 September 2026, 4:10–5:00 p.m., HSSC N1170.
Middle of Everywhere (Taiwan)
Peer
Musical, theatric, sporting, academic, and similar events involving this
section’s students are welcome.
- Saturday, 12 September 2026, Grinnell Track.
Les Duke Invitational (Cross Country)
Wellness
- Wednesday, 9 September 2026, 6:30–8:00 p.m., Bear Dance Studio.
Brazilian Jiu-Jitsu
- Saturday, 12 October 2026, All Day, Somewhere.
Mental Health Training.
- Sign up on handshake.
- It’s all day, so you will earn 3.
- Monday, 14 September 2026, 6:30–8:00 p.m., Bear Dance Studio.
Brazilian Jiu-Jitsu
- Monday, 14 September 2026, 8:00–9:00 p.m., Prayer Garage.
Meditation Group
- Tuesday, 15 September 2026, 4:30–6:00 p.m., Bear P103.
Wellness Yoga
Misc
- Wednesday, 9 September 2026, 8:00 p.m.–9:00 p.m., Noyce 3rd.
Mentor Session
- Thursday, 10 September 2026, 8:00 p.m.–9:00 p.m., Noyce 3rd.
Mentor Session
Other good things
These do not earn tokens, but are worth your consideration.
- Wednesday, 9 September 2026, 4:30–6:00 p.m., Springer Field.
Women’s Soccer vs. Coe
Upcoming work
- Due Thursday, 2026-09-10:
- On Friday, 2026-09-11:
- Quiz/LA on tracing (quite similar to the end of today’s lab)
- REDO Quiz/LA on decomposition.
- REDO Quiz/LA on procedures.
- Due Tuesday, 2026-09-15:
Administrative Q&A
How do I turn in a report for a token?
Go to the Tokens Submit assignment on Gradescope. Enter details.
How long does the paragraph have to be?
A few sentences. Reflect, don’t just report.
What happens if I don’t finish a lab?
You should submit what you finish in class at the end of class.
I’d recommend that you read the rest of the lab and then attempt any
questions that seem difficult to you.
When can I make up an LA?
There are makeups every Friday. There are also extra makeup times
available. 7:30–8:00, 11:00–11:30, 4:00–4:30.
Do I have to write reflections to get a token for mentor sessions?
Yes.
What happens if I turn in a reflection more than 72 hours after the event?
I’ll be slower in grading it.
Did my lab partner turn in the lab and include me?
You can check on Gradescope. If you see an entry for your name, they did.
If not, they either didn’t turn it in or forgot to include you.
Note that the two of you should turn in the lab together at the end of
class.
Quiz notes: Decomposition
Key idea: Break a complex set of instructions into smaller parts and
name the parts.
Why? (TPS)
- It makes it much easier to read and understand (at least if we choose
good names). [+2]
- It’s easier to understand smaller chunks of code separately.
- The names also help.
- It could be more efficient. [+1]
- It’s easier to change the code.
- It’s generally helpful.
- There’s an opportunity for reuse. [+1]
- Clarifies things for ourselves.
- Easier to find bugs.
- Avoid duplicated code. **
Demo solution
Not included in eboard.
Grading notes
- If you did not avoid repeated code, you likely got an Not-yet-satisfactory.
- Many of you neglected to put the person back together. I considered
calling that Not-yet-satisfactory, but then reread the instructions, which
did not make it clear that you had to do so.
- If you did not choose good names, it was not-yet-satisfactory.
Questions
Can we bring another sheet of paper to the retake?
One per quiz. It can be the same sheet of paper. It can be the same sheet
of paper with additional notes (if there’s room). It can be a brand new
sheet.
Why did Sam write “Not a procedure”?
One reason: You wrote (define something (lambda (param) ...)), and
the instructions explicitly said “Do not write a procedure”.
Another reason: You wrote something like (head), which is syntactically
incorrect because you cannot put parentheses around a value. This did
not lose you credit; it was just a simple syntactic issue that I wanted
to remind you about.
Quiz: Procedures
Key idea: Name and parameterize sets of code.
Why? (TPS)
- Naming things helps us know what they do
- Lets us generalize behavior [+1]
- You don’t have to write the same thing for similar actions
(e.g., making different size people, or people with different
color ties).
- If we write the procedure, we can call it with different parameters
to get different effects.
- Naming the parameters can also clarify things: It tells you what
the different values represent.
- Makes the code more readable to other people.
Demo solution
Not included in eboard.
Grading notes
- Sorry, that was a bad quiz.
- If you wrote a procedure for the building and one for the window, you
probably got credit. Otherwise, try again this week; it will be better
(but different).
- Don’t forget to use lambdas to define procedures!
- You can’t nest defines. Sorry!
Questions
Will the mentors go over practice problems in the mentor sessions?
Definitely! That’s the main purpose of mentor sessions.
Lab
Do the lab on Gradescope.
I’d encourage you to finish the lab on your own to prepare for Friday’s quiz.