Philosophy 12
Logic and Decision Making
Fall 2009, Tues. Thurs. 12:30-1:50 pm

Professor: William Bechtel
Office: HSS 8076
Telephone 822-4461
Office Hours Tuesdays, 2:00-3:30 pm and by appointment


Sections TA Office Contact Office hours
A01 Wednesday, 8 am Damon Crockett HSS 8089 Wednesday, 10:00-Noon
A02 Wendesday, 9 am Damon Crockett HSS 8089 Wednesday, 10:00-Noon
A03 Friday, 1 pm Benjamin Sheredos HSS 7039 Tuesdays, 2:30-4:30 pm
A04 Wednesday, 2 pm Benjamin Sheredos HSS 7039 Tuesdays, 2:30-4:30 pm

1. Course Description

Reasoning and decision making are two of the most important activities in which humans engage. But we don’t always do so in the best manner. When we don’t, the consequences can range from minor inconvenience to catastrophic loss. One of the contexts in which humans have best developed their capacities for good reasoning and decision making is scientific inquiry. Hence, that is where we will turn for guidance. Science is also extremely important to our own decision making as we rely on the results of scientific inquiry. This requires, though, that we understand how science works and be able to assess whether a given result is trustworthy.

Some of the questions we will address are: (1) What makes for a good piece of reasoning in science? (2) Can you ever be absolutely certain of the truth or falsity of a scientific hypothesis? (3) How objective is observation and how can humans avoid making mistakes in perception? (4) What might we learn by systematic observation? (5) What can we learn from discovering correlations between variables and how can we avoid being misled by illusory correlations? (6) What does it take to establish a causal relationship? (7) What are mechanisms, what role do they play in science, and how do scientists discover and reason about them?

This course will emphasize active engagement in the kinds of reasoning and decision making which scientists use in developing and testing hypotheses, especially through on-line exercises and demonstrations. The goals of the course are for students to understand the logical and statistical principles by which scientific claims are created and evaluated and to develop a critical appreciation for the methods by which knowledge is acquired in science. You should leave this course with a better ability to distinguish good from poor reasoning and decision making in science and other domains.

2. Course Materials

The primary course materials are on the course website at Login directions and initial login codes are included in the course reader, available at the UCSD bookstore (be sure you buy a new reader--used initial logins cannot be reused). The modules found on the website include text, animation, and interactive exercises, of which only the text is included in the reader. Some modules have questions to answer at the end. All activity on the site is recorded and logged, including answers to question sets attached to the modules. Completion of the on-line exercises is a requirement of the course.

Apart from the course package, you will also need to purchase a transmitter for the Inter-Write PRS RF System, the student response system used in this class. These transmitters, informally called “clickers,” are also available at the UCSD bookstore (across from the Infomation Counter) and cost $52.00 (new) or $39.00 (used). You may be able to use the same clicker in other classes, particularly in science classes. Make sure to get a new-style clicker operating at radio frequency (RF) and not an old-style infrared one.

3. Course Requirements

For each module, students are expected to complete it and any questions attached to it, before attending the class for which it is assigned. Attendance in class and sections is required. Final grades will be based 25% on the mid-term, 25% on the final exam, 30% on two-short (1- 2 pages) written assignments, 10% on your "clicker" score, 5% on quizes and participation in sections, and 5% for timely completion of the web-based exercises and questions. Exams must be taken at the assigned times and papers submitted by the scheduled times to receive credit. The following scale will be used to convert numeric scores to letter grades: 98-100 A+, 93-98 A, 90-93 A-, 88-90 B+, 83-88 B, 80-83 B-, 78-80 C+, 73-78 C, 70-73 C-, 60-70 D, below 60 F. For students taking the course pass/no pass, a C- (70) is the minimum grade for receiving a pass.

Your "clicker" score will be based on in-class questions scored using the InterWrite PRS RF student response system. During each class (except the first), you must “buzz in” and the system will automatically record your responses, and then transmit them to me. Several times during each class, I will put up a question for you to answer. You will receive one point per class meeting if you respond to each question and a proportion of a point if you respond at least half the questions but not all. Your clicker score will be the percentage of points earned divided by the maximum possible. Thus, if you earn 14.5 points and the maximum is 16, your score will be 91%. Important: you must have your clicker every class period to get these points—no exceptions.

In all your work for this course you must observe the University’s Policy on Integrity of Scholarship, which can be found at

4. Email List

There are email distribution lists for this course, one for each section. It is required that you subscribe to the list for your discussions section. Do it IMMEDIATELY. You can always unsubscribe later if you drop the course or change sections. The purpose of the list is to allow the TAs and me to distribute information regarding due dates for assignments, changes of schedule, etc. Some of this information is crucial, and some of it may be distributed early in the quarter. To subscribe, you simply need to send an email message to the address corresponding to your section
Section A01 –
Section A02 –
Section A03 –
Section A04 –
After you send the subscribe request, you will receive a reply from sec0* (where * is the number of your section) that will ask you to confirm your request. Follow the directions in this message to confirm you subscription. If you later want to remove yourself from this list, send email to sec0*

Only the TAs and I have authorization to send mail to this list. There should be no spam. If you receive mail from this list that is not from one of us, be assured that I will as well and will take measures to block further abuse. (The welcome message you receive suggests that you can send email to the list. Sorry, but you cannot.)

5. Schedule of Classes and Web Assignments

Note: This schedule of reading assignments is tentative and subject to revision. Items in italics are modules on the Inquiry website. You should complete these, including any attached questions, before the assigned class (although subsequent review is certainly encouraged).

Copies of the powerpoints presented in lecture are available on line. (They may well be revised before being presented, and if so, updates will appear around the time of the relevant class.) Click here for access to the lecture notes

September 24 : Introduction: The Inquiry Website and Exemplary Scientific Reasoning

September 29: Elements of science: Introduction to Scientific Reasoning, Statements: the atoms of reasoning; Justification and argument
October 1: Valid arguments: Some basic valid argument forms

October 6: Confirmation, falsification, and fallibility: Evidential relations; The fallible character of human knowledge
October 8 : Observation and categories: Observation and learning to see

October 13: Categorizing phenomena: Categories and taxonomy
October 15 : Observational research: Observational research

October 20: Distributions and samples: Variables and measurement
October 22: Midterm Exam

October 27: Predicting relationships between variables: Predicting relations between variables
October 29: Predicting from correlations: When variables are correlated

November 3: Differences between means: When variables are not correlated; When groups differ
November 5: Correlation and causation: Correlational studies as tests of causal claims; Correlational vs. experimental research
First 1-2 page written assignment due: Friday, November 6 by Noon (papers should be in .doc or .rtf format and emailed as attachments to your TA)

November 10: Causal explanation: Causal explanation
November 12: Reasoning about and graphing causes: Reasoning about causation; Causal reasoning with directed graphs

November 17: Causality and experiments: Testing causal claims experimentally
November 19: Causation when experiments are not possible: When randomized experiments are not possible
Second 1-2 page written assignment due: Friday, November 20 by Noon (papers should be in .doc or .rtf format and emailed as attachments to your TA)

November 24: Mechanism and mechanistic explanation: Entities and activities organized to produce a phenomenon

December 1: Organization and levels of organization: Levels of organization within mechanisms; Describing and portraying mechanisms
December 3 : Discovering and modeling mechanisms: Experimenting on mechanisms

Final Exam: Friday, December 11, 11:30 am -2:29 pm