Courses/Computer Science/CPSC 203/CPSC 203 Template/Lecture Template/Lecture 14
Contents
Housekeeping
Required Reading
Recap of Key Ideas from Lectures 8 -13
- We can view the world as sets, and operations on sets. A group of sets and their relationships can be considered a system. (Lecture 8)
- In particular, if we focus on data in systems, we arrive at the Relational Database meta Model. This provides a consistent way of modelling the data aspects of a system. E-RD diagrams give us a shorthand to sketching the major aspects of such a model, ignoring the details. (Lecture 9).
- When the world is modelled this way -- we investigate patterns in the data by defining queries. We can build a model of how queries are accomplished via the Query Trace Mechanism. (Lecture 10)
- For a wide range of systems we could model, there are often a small set of query patterns that allow us to extract useful information. (Lecture 11)
- Using these query patterns sequentially, we can move up the hierarchy from data to information (and perhaps to knowledge). This requires us to work backwards from our questions, and define a path from raw data to solution (Lecture 12)
- Finally, we arrive at a "Relational Thinking" style that allows us to look at the world in terms of base sets, and relationships between base sets. (Lecture 13).
- Some aspects of our relational world view are very algorithmic: e.g. Query Trace Mechanism, Relational Operations, Basic Query Patterns.
- Other aspects of our relational world view are more heuristic: E-RD drawing, database design.
Introduction
Glossary
Concepts
Today we will look at three pairs of concepts that are important to problem solving.
- Deduction and Induction
- Generalization and Specification
- Discovery and Confirmation.
With each pair there is a polar tension between the concepts.
Summary
Often there is a contrast between approaches to Problem Solving, for example:
- Between Induction and Deduction
- Between Generalization and Specification
- Between Discovery (creative) and Confirmation (methodological).
Text Readings
Resources
Renyi, A. 1984. A Diary on Information Theory.
- Source of the "Bar-Kochba" guessing game example.
Polya, G. 1945. A New Aspect of Mathematical Method.
- Source of "Generalization" and "Specification"
Hempel, G. 1966. Philosophy of Natural Science.
- Source of Induction, Deduction Definitions.
- Source of example on Ignaz Semmelweis' investigation of Childbed fever.
Homework
- A Practice Quiz is on BlackBoard (BB) under "Course Documents". Answer sheet will be put on BB for Tuesday's class.
Two additional Database Design practice questions are below.
DB Design Question 1
In the airline industry, a "Ticket" is made up of one-or-more "Coupons" that detail the specifics of the flights you take. The business view of a coupon has the following sets of information.
- Coupon (class, status, confirmed indicator, comment)
- Flight (date of departure, time of departure)
- Airline Route (flight number, scheduled departure date)
- Airline (code, name)
- Airport (code, name)
- Ticket (date of issue, fare, currency)
- Person (name, title, initial)
Create an E-RD based on this information and your general knowledge of air travel.
DB Design Question 2
An organization has the following structure:(represented as nested lists)
- Headquarters (Support Division, Business Systems Division, Sales Division)
- Business Systems Division (Training Department, Development Department, Consultancy Department)
- Consultancy Department (Team A, Team B, Team C)
Create an E-RD based on this organization structure.
