Held: Friday, 30 August 2013

On to Outline 02 - An Introduction to Linux.

Summary

We begin the class by exploring the definition of computer science and by trying to write some basic algorithms.

Related Pages

• EBoard (Source) (PDF)

Overview

• Introduction: What is CS?
• Exercise: An everyday algorithm.

Administrivia

• Don't forget that we have class on Monday!
• Welcome to CSC 151. I hope you have a great time!
  (Particular welcomes to the first-year students.)
• Warning! Your first assignment is due this Sunday at 10:30 p.m.
  (And yes, you have to complete the assignment even if you are not yet registered for the course.)
• This course is very overenrolled. Please put up with the extra chaos for the first few days. Please also let me know asap if you are dropping the course so that I can add poeple from the waiting list.
• I don't believe in going over class policies on the first day. Please read the course web and ask me questions via irc, email, or in the next class.

An Introductory Question

• Rather than telling you exactly what the class is about, I'm going to start the class with a question for you.
  • The question will help ground the class.
  • The question will begin to get you used to some aspects of my teaching style (particularly my reliance on recitation-style work).
  • The question will test your abilities as a liberal artist.
• What is Computer Science?
• I will give some of my own responses after I've heard some of yours.

What is CS?

• Computer scientists differ in how they define the discipline. However, most would agree that, at least in part,

  Computer science is the study of algorithms and data structures.

• By "algorithms", we mean sets of instructions that can be used to solve problems.
  
  • Some problems are mathematical. For example, you might write an algorithm to find the square root of a real number.
  • Other problems deal with textual information. For example, you might write an algorithm that tells how to find a name in the phone book.
  • Still other problems deal with graphical information. For example, you might write a program that finds text in an image (and then figures out what the text is).
  • Clearly, you can write algorithms for a wide variety of problems.
• By "data structures", we mean mechanisms for organizing information. For example, we organize some information in lists, other information in tables, and other information in more complex structures.
• By "study", we mean specify, design, describe, evaluate mathematically, evaluate experimentally, implement in software, implement in hardware, prove properties, consider applications and implications, and much, much more.
• In our studies, we rely on the tools and techniques from a number of other disciplines.
  
  • From mathematics, we take proof techniques, formal language for describing problems and solutions, and even core ideas.
  • From science, we take an experimental approach. We show that an algorithm is "correct" by constructing a variety of experiments.
  • From engineering, we take techniques for designing and constructing things.
  • From psychology and the social sciences, we take techniques for understanding the relationship of our work to human endeavors.
• These diverse perspectives and skill sets make CS interesting and challenging.
• Our European colleagues often refer to the discipline as "Informatics" (that is, implying the study of information), and I will admit that I have come to prefer the term because it distances us a bit from both computers (we are broader than the technology) and from science (since we do not necessarily emphasize the scientific method).

An Everyday Algorithm

• We'll explore the problems of writing clear instructions through a simple exercise.
• Challenge: Write a clear, unambiguous, and detailed set of instructions for making a peanut butter and jelly sandwich.
• Format: Work in groups of about four.
• Each group will write its solution on one of the four boards.
• SamR will play the role of the sentient, but malicious and clueless "follower of instructions".
• We will do some debriefing today, and additional debriefing in the subsequent class.