Class 1

Held: Friday, 25 August 2017

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

Preliminaries

Overview

• Introduction - What is CS?
• Exercise - An everyday algorithm
• Debriefing on exercise
• Common parts of an algorithm

Related Pages

• Eboard 1 (Source)

Updates

News / Etc.

• Welcome to CSC 151!
• I’m Sam (or SamR)
• Your class mentors are Anh Thu, Ritika, and Zander.
• You should have received four handouts at the start of class.
  • A playing card
  • The CS Department Academic Honesty Policy
  • Assignment 1
  • A packet of readings
    • Reading: Algorithms
    • Reading: Linux
    • Reading: The DrRacket Programming Environment
    • Reading: Beginning Scheme
• At the end of class, please restore your station to its original state (or better): Push in your chairs, put the nodepad neatly next to the machine, give your playing card back to the mentors, etc.
• The CS department maintains a listserv of announcements of events and opportunities. If you would like to be added to that listserv, please send me an email.
• Warning! I’m losing my hearing. I’m also snarky. The two are independent.
• Since it’s the first day of class, I’ll be taking attendance.
  • It always takes me a few weeks to learn names. This semester it will take even longer, because I am teaching approximately 150 students.
  • This exercise will probably take ten minutes. That’s okay, I consider it worth the time. I hope you do, too.
  • When I call your name, please stand up and respond with something like the following
    • “Hi, my name is FORENAME SURNAME.”
    • “You can call me PRIMARY NAME.”
    • “If you must address me by surname, you can call me Mr./Ms./Mx./[nothing] SURNAME.”
    • I’m from LOCATION.
    • Optional: “My pronouns are ….”

Upcoming Work

• Assignment 1 Due Sunday night.
• Readings (handed out today), due before class Monday.
• Signed academic honesty policy due in class on Wednesday.
  • If you are uncomfortable signing it, make an appointment to chat with me.

Extra credit (Academic)

• CS Table, noon, Tuesday, Whale Room (I hope)

Extra credit (Peer)

None yet.

Good things to do

• Ag Days in Grinnell, Thursday the 31st. More info forthcoming.

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 computer science?

• 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 nut butter and preserves sandwich.
• Format: Work in groups of about four.
  • I will distribute playing cards to help you identify those groups.
• 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”.

Debriefing

• We will consider some of the implications of the activity today.
• Model: Discuss implications in your small group. Then pick a few important topics to share with the larger group.
• We will continue debriefing in the next class period.