The course is designed to enable students to appreciate, use and understand ideas at the core of computer science. This course covers ideas that will be useful and interesting to students, whether or not they major in computer science.
Course Description. In the past hundred years, computer science has changed the world more than any other field. Without computer science, humans would not have walked on the Moon, modern medicine would not exist, and Wal-Mart would be a small store in Arkansas. But this course is not just about the pragmatic impact of computer science; it is about how computer science changes the ways we think, solve problems and understand the world.
Despite its name, computer science has very little to do with the beige boxes we call computers, and it is far from being a science. It has more in common with music and mathematics than it does with science or engineering. At its core, computer science is the study of imperative knowledge. Whereas mathematics is all about declarative knowledge ("what is"), computer science is all about "how to" knowledge.
Computer science is the study of information processes. Computer scientists study how to describe, predict properties of, and efficiently implement information processes.
Most of what we know about describing information processes stems from three simple ideas:
The kinds of properties we want to predict about information processes include whether or not there is a procedure that can always solve a given problem (computability), and how much time and space will be required to solve a given problem (complexity).
Expected Background: This course is open to students with no prior background in computer science or programming, but appropriate and challenging for experienced CS majors also. The only background we assume is:
Meetings: Mondays, Wednesdays and Fridays at noon-12:50 pm in MEC 341.
Books: The required coursebook is Introduction to Computing: Explorations in Language, Logic, and Machines by David Evans. You can download the book from http://www.computingbook.org and print it yourself or order a printed copy from lulu.com ($12.95).
In addition to the required textbook, there are three strongly encouraged optional books:
Course web page/blog: http://www.cs.virginia.edu/cs1120. This page is updated often and students are expected to visit it regularly (almost every day). All lectures, notes and assignments for the course will be posted on the web site. You may also want to subscribe to the RSS feeds: entries, comments.
Problem Sets. There will be eight problem sets and one larger project. The problem sets involve both written questions and programming problems. Some problem sets will be done by small groups of students. For almost all students, doing the problem sets will be the best way to learn the course material.
The expected problem set due dates and topics (which are subject to change) are:
Unless noted otherwise, problem sets are due at the beginning of class (10am) on the day they are due.
Quizzes. There may be several short in-class quizzes throughout the semester. These may or may not be announced in advance, and may or may not impact your grade.
Exams. There will be two exams during the semester and a final. All exams will be open book and open notes. All exams will be take-home unless I have any reason to believe there are any untrustworthy students in this class.
Students are also encouraged to consult outside sources, including human experts. Always list the resources you used (students, outside experts, papers, web sites) on your submission. The only resource you may not use are problem sets from previous semesters of cs200, cs150, and cs1120. It is to your advantage for the course staff to be able to reuse effective assignments from previous semesters, and important that we can trust you to not abuse those materials.
All students are required to sign the course pledge, which applies to the entire course.
The main topics of the course include:
Language. Be able to identify the primitives, means of combination, and means of abstraction for a language; describe a language using a replacement grammar or recursive transition network; determine the set of the surface forms in a language described by a replacement grammar or recursive transition network; determine what a surface form in a language means if you are given evaluation rules for the language; determine the value of a Scheme expression following the rules of evaluation. Understand an interpreter; modify an evaluator to change the meaning of a language; explain why the difference between eagar and lazy evaluation matters.
Defining and Understanding Procedures. Be able to define and understand procedures including procedures that take procedures as parameters, procedures that produces procedures as results. Understand recursive definitions and be able to solve problems by defining a recursive procedures and reason about the process produced by evaluating an application of a recursively defined procedure.
Data, Mutation, and Objects. Understand how complex data can be constructed from simple structures, and how to define and manipulate recursive data structures. Be able to define, use, and understand procedures that manipulate lists and trees. Define and understand procedures that use mutation; draw environment diagrams; explain what environment diagrams mean; define procedures that create objects; explain a class hierarchy; define procedures that use inheritance; explain how a method is selected given class definitions.
Analyzing Problems and Procedures. Describe problems precisely in terms of their inputs and outputs; express the amount of work a procedure requires using Θ notation; describe a problem using O, Ω, and Θ; estimate the amount of work a solution to a problem involves; classify problems into complexity classes P and NP; explain convincingly why a problem is in NP; explain what it would mean if someone developed a fast (polynomial time) procedure for an NP-Complete problem.
Modeling Computation. Explain how to model computation; understand a finite state machine description and explain what it does; understand a Turing Machine description and explain what it does; show that a computing model is (or is not) capable of modeling any mechanical computation; explain what it means for an axiomatic system to be perfect, incomplete or inconsistent; explain the essence of Godel's proof; determine if a problem is computable or noncomputable and provide a convincing argument why.
For students who do not succeed in convincing me they can think like a computer scientist, grades will be based on approximately the following weighting:
| Problem Sets | 45 | (40-70) |
| Quizzes | 5 | (0-15) | Exam 1 | 15 | (5-15) | Exam 2 | 15 | (10-20) | Final Exam | 20 | (15-50) | Class Contribution | 0 | (0-10) |
Grades will be tabulated varying the weights assigned to each category in several different ways using the ranges above. In general, the weighting that is best for you is used.
Spend your energy focusing on what you are learning, instead of worrying about your grade. Although the material we cover is challenging, and the pace may seem overwhelming at times, historically all students who put effort into this class have done fine. Although not everyone will succeed, all students are expected to get an A in the course. Students who do outstanding work in the course will be considered for funded summer research positions in Prof. Evans' research group.