Assignment Type 1: Simple and Compound Statements

Goals and Objectives

• Exhibit the difference between and and or and use not as applied to a database.
• Formulate queries in both symbolic logic form and general database syntax.
• Introduce the idea of identifying keywords and assigning of variables.
• Introduce the concept of literal strings.
  • The Information Literacy session should stress the difference in the variable assignment used in class (see Variable Assignment below) versus using the literal string (phrase) syntax of the actual database
• Exhibit the difference is searching for a string versus the typed words.
• Introduce particular database syntax.
• Apply the distributive equivalence and DeMorgans Law.

Global Warming Example

Variable Assignment

• i = ice age
• w = global warming
• g = greenhouse
• e = effect
• a = gas
• r = greenhouse effect
• s = greenhouse gases

Questions

 

1. Determine the number of hits for the search (query)
   1. i.

    

    

    

    

2. Explain, using the number of hits, which search would give you the desired articles you require for your research paper:
   1. i \/ w
   2. i \/ w
   3. Using the letters, 1, 2, 3 and 4 in the Venn Diagram , describe the regions for each of the previous expressions, where the A is the set of articles that contain ice age and B is the set of articles containing global warming.

    

    

    

3. Suppose you wanted to find articles about the ice age that did not talk about global warming. Which expression would you use and why?
   1. i \/ ~w
   2. i \/ ~w
   3. Using the numbers, 1, 2, 3 and 4 in the Venn Diagram , describe the regions for each of the previous expressions, where the A is the set of articles that contain ice age and B is the set of articles containing global warming.

    

    

4. Use the information / number of articles from the following parts o answer the questions.

    

   1. Do you receive more or fewer hits as compared to the previous part with the following search.
      1. i \/ ~w \/ ~r \/ ~s

         If you receive the same amount of hits, is that just a particular instance of what you are searching for? Explain your answer using the next question.

       

       

       

       

   2. Rewrite the i \/ ~w \/ ~r \/ ~s search using DeMorgans Law.

       

   3. Write the query and the logic expression that determines
      1. if the phrase greenhouse effect appears but not greenhouse gases
      2. if the phrase greenhouse gases appears but not greenhouse effect
      3. Using the letters, 1, 2, 3 and 4 in the Venn Diagram , describe the regions for each of the previous expressions, where the A is the set of articles that contain greenhouse effect and B is the set of articles containing greenhouse gases.

       

       

   4. Comparing to the previous part, would you expect
      1. r \/ s

         to produce more, fewer or the same number of articles?

       

       

       

       

       

    

    

5. You decide you want to find additional articles about the greenhouse effect, you enter the following searches below. Are the number of hits the same? If not, can you give an example of situation where an article would appear in one search but not the other? If the number of hits is the same, try the query in a different database.
   1. g \/ e
   2. r

    

    

    

    

    

    

6. Determine the number of hits from the following query and rewrite it using the Distributive Law and determine the number of articles for each.
   1. (g \/ e) / (g \/ a)

    

Assignment Type 2: Precedence Of Operators

Goals and Objectives

• Exhibit the use of paraenthesis.
• Show that databases have a precedence of and and or.
• Introduce the idea of identifying keywords and assigning of variables.
• Introduce the concept of literal strings.
  • The Information Literacy session should stress the difference in the queries
• Connect logical operators to Venn diagrams and set operators.

1. (a \/ e) \/ g
2. a \/ (e \/ g)
3. a \/ e \/ g

Global Warming Example

Assignment 2

Databases that can be used:

• database whatever
• second database
• etc

Connecting Sets and Logic

 

 

1. Using the Venn diagram, let A = { articles containing "global warming"} B = { articles containing "polar bears" } C = { articles containing extinction } Give

    

   the set (use the numbers) that represent the following queries:

    

   1. "global warming" and "polar bears" and extinction
   2. ("global warming" and extinction) and not "polar bears"

       

   3. ("global warming" or "polar bears") and extinction
   4. ("global warming" and extinction) or ("global warming" and "extinction")

    

2. Using the Venn diagram, let A = { articles containing "global warming"} B = { articles containing "polar bears" } C = { articles containing extinction } rewrite the queries in the previous part using union , intersection and complement ‘ and the set letters.
   1. "global warming" and "polar bears" and extinction
   2. ("global warming" and extinction) and not "polar bears"
   3. ("global warming" or "polar bears") and extinction
   4. ("global warming" and extinction) or ("global warming" and "extinction")

    

    

3. Using the Venn diagram, let A = { articles containing "global warming"} B = { articles containing "polar bears" } C = { articles containing extinction } In what region (numbers) would you find the following articles:
   1. Articles on "global warming" and "polar bears".
   2. Articles on extinction or "global warming"
   3. Articles on extinction and "polar bears" but do not discuss "global warming"

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