Spring 2026 Computer Science 4580. 1/28/2026

Logical Problem of the Day

Survey quiz results:

Question 1. You are given a choice: (a) get $900 for certain, or (b) 90% chance to win $1,000 and 10% chance for nothing. What do you choose? [88%, 12%]
Question 2. You are given a choice: (a) lose $900 for certain, or (b) 90% chance to lose $1,000 and 10% chance of losing nothing. What do you choose? [9%, 91%]
Question 3. Linda is thirty-one years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations. The respondents are asked to rank in order of likelihood various scenarios: Linda is (1) an elementary school teacher, (2) active in the feminist movement, (3) a bank teller, (4) an insurance salesperson, or (5) a bank teller also active in the feminist movement. [26%, 42%, 2%, 2%, 28%]
Question 4. An individual has been described by a neighbor as follows: “Steve is very shy and withdrawn, invariably helpful but with very little interest in people or in the world of reality. A meek and tidy soul, he has a need for order and structure, and a passion for detail.” Is Steve more likely to be a librarian or a farmer? [67%, 33%]
Question 5. Participants were asked to choose between two treatments for 600 people affected by a deadly disease. Treatment A was predicted to result in 400 deaths, whereas treatment B had a 33% chance that no one would die but a 66% chance that everyone would die. This choice was then presented to participants either with positive framing, i.e. how many people would live, or with negative framing, i.e. how many people would die.
Choice one: Either saves 200 lives, or a 33% chance of saving all 600 people, 66% possibility of saving no one. [80%]
Choice two: 400 people will die or a 33% chance that no people will die, and 66% probability that all 600 will die. [20%]
Question 6. Write down the last 2 digits of your Social Security number. Now consider whether you would pay this number of dollars for items whose value you do not know, such as wine, chocolate and computer equipment. Finally, how much are you willing to pay? (Enter two numbers) [(12, 12), (13, 15), (67, 25), (69, 19), (74, 74), (54, 54), (99, 99), (49, 49), (13, 20), (92, 40), (12, 50), (96, 30), (35, 15), (12, 20), (78, 28), (44, 30)] Anchoring average: [211/8=26.3 vs 369/8=46.125] See question6.txt.
No polleverywhere question today.

Canvas Quiz of the Day (need daily password)

Most days, there will be a simple canvas quiz related to the lecture. You need a password to activate the quiz, which I will provide in class. These quizzes will count toward your class participation grade. The quiz is available only during class.

Click for today's quiz. Hint: see below.

Announcements

Let us know if you have an upcoming event you would like to share with the class.

Yale Information Society Project Free lunch. This week.

This Wednesday, we have a guest speaker, Dan Russell, ex-Google. Attendance is required. See Dan's Wikipedia page. We will go out to dinner with Dan at Mory's at 6pm, including 5-6 students. The following students won the lottery to go to dinner.

Joshua Li
Yuwang Ma
Yide Jin
Helen Mao
Bende Doernyei
Tony Chang

The following students are alternates, in case one or two of the above students can't make it.

Elizabeth Schaefer (NOT AVAILABLE)
Isabelle Millman

There is also a Discussions question for commenting on the speaker, available Wednesday: What did you learn from today's speaker, Dan Russell? What was the best question from the audience? Did you ask it?

Next Monday, we have another guest speaker, John Niccolai, Chief Operating Officer of Fixed Income and Macro, Citadel. We will have dinner at 6pm at Villa Lulu, 239 College Street. If you want to come to dinner, again sign up in the designated Discussion in canvas (not Ed Discussion) before Friday. I will run the lottery offline this time and post the results on Friday.

Lecture

I have office hours Mondays and Wednesdays from 2:30-3:30pm pm, on zoom, id 459 434 2854.

Complete the online student information sheet.

Assignments

You can begin work on hw 1 Note: I have posted the dates for the remaining assignments. Plan accordingly.

The Realm of Decisions

We shall explore Langer's mindlessness / mindfulness dichotomy for decision making. For the next class and the coming weeks: Give an example of an explanation you thought interesting because it was especially good or bad. It can be personal or from the news. Use the Discussions section of canvas (not Ed Discussion). You earn a quiz point by posting to Discussions. Try to analyze it along the mindless / mindful spectrum.

Truth is more complicated that the logicians would have you believe. Quotes about Truth

The VOTE program is available on the zoo. There is also a github repository of the Common LISP code for VOTE.

Behavioral Economics

PIMCO Behavioral Science

What is a correct decision? See A Realistic Model of Rationality. This short paper provides a high-level introduction to the topics we will discuss in this course: goals, plans, resources, relationships, goal adoption, explanations, subjective decisions, emotions, advice, and persuasion. We contrast it with the standard economic decision theory. We want to develop a theory that can be implemented in a computer program.

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