EBoard 05: Mental Models (Section 3)
Warning! You are being recorded (and transcribed) (provided the technology
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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.
- We hve lots of computers down because of the network problems. Start
at the dead computers and then move to a working one once the lab starts.
- During class, please work on our workstations, not your laptops.
- Congratulations to our football team for their season-opening victory!
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
- 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
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 earn 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.
Did Sam grade the quizzes?
Whoops! Yes. They are on Gradescope.
Quiz notes: Decomposition
Key idea: Break a complex set of instructions into smaller parts and
name the parts (perhaps with a clear name).
Why? (TPS)
- It can be easier to figure what went wrong because we can try each
component separately.
- Readability: The names can make things easier to understand, not only
for you, but also for others. [+1]
- We tend to be better at remembering smaller things, and this lets
us build smaller things.
- When we need multiple copies of the same thing, we can refer to the
same name again and again, rather than writing long pieces of code
again and again. (Reuse) (Condense the code) [+1]
- Also makes you easier to change things. For example, if you’re unsatisfied
with how an eye looks, you can change only one definition.
Demo solution
Not included in eboard.
Grading notes
- If you left the eye unnamed: Not-yet-satisfactory because you should
be eliminating repeated code.
- If you left the bow unnamed: Could still be satisfactory.
- If you chose bad names, like “black-square”, Not-yet-satisfactory
- If you put parenthesis around a named value, like
(eye), I wrote something
on your quiz, but it did not affect your grade.
- If you wrote your own procedures, you got a Not-yet-satisfactory because
it explicitly said not to write procedures.
Questions
When can we make it up?
The quiz time for this class starts at 3:30 p.m. and runs until the
end of class at 4:00. You can also stay until 4:30 p.m.
Will the questions be the same?
Nope. Different questions about the same topics.
Quiz: Procedures
Key idea: Name and parameterize sets of code.
Why? (TPS)
- Can make our code shorter because we can call upon the procedure again
and again.
- It generalizes our code, which lets us use it in more situations.
- It lets you build variants of the original computation without copying
and pasting large amounts of code.
- It makes it easier to change things. Rather than worrying “Which of
these colors should I change”, you can just change one paramter.
- UM: It helps you use math
- Naming things adds clarity/resolves ambiguity.
- Naming the function
- Naming the various parameters/values
Demo solution
Not included in eboard.
Grading notes
- Three procedures is more than I should ask for. I gave you credit for
a decent window procedure plus a decent building procedure.
- Don’t forget to write the lambda when creating a procedure.
- You can’t nest
define statements. (Sorry.)
Questions
Lab
Do the lab on Gradescope.
I’d encourage you to finish the lab on your own to prepare for Friday’s quiz.