Class 02: Algorithms: Thinking Formally

Held Wednesday, January 24, 2001

Summary

Today we continue getting started with the class by trying to formally give instructions for an everyday problem and by working with the MathLAN workstations.

Due

• Introductory survey
• Consideration of course web

Assignments

• Read SamR's Quick HTML Reference

Notes

• As many of you have discovered. this course web is still under development. Send me email when you notice missing links or other problems.
• My eldest son (William, 5) is sick. I won't be available this afternoon (except by email) or much of tomorrow. You should feel free to send me email and I'll respond as soon as possible.

Overview

• An algorithm for making sandwiches
• Generalizing: What techniques did we use?
• Lab: Getting started in the MathLAN.
• Lab: Getting stared with Blackboard.

The Need for Formality

• Some people wonder why we need computer languages like Scheme, Pascal, C, Java, and the ilk.
• In part, it's probably because the computer elite want to maintain their sense of superiority over the masses.
• In greater part, it's because English and other natural languages can be ambiguous. At the very least, they have many similar structures that are interpreted very differently. Consider the classic pair of
  • Time flies like an arrow.
  • Fruit flies like a banana.
• As I've said (and will say again), computers are sentient and malicious. it often seems that they'll do their best to misinterpret whatever it is you write.

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 eight.
• 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".

Lab: Getting Started in the MathLAN

• Since much of this course is hands on, let's get started.
• See the accompanying laboratory handout.

Lab: Getting Started with Blackboard

• There's a second Web site for this course, one that uses' the college's Blackboard server.
• Today or tonight, try to complete the laboratory on Blackboard.