Title: Complex Conditions Direct Answer

Author: Kate Deibel

Date: March 29, 2004

Technique: Direct Answer

Before Class Preparation Time: MEDIUM

Class Completion Time: MEDIUM

In-Class Analysis Time: LOW

Out-Of-Class Analysis Time: LOW

Assessment Goals:
Topics:
Purpose:

Instructors can find out if students can apply De Morgan's laws correctly to conditionals.


Activity:

Please simplify the following conditionals so that the ! operator is only used as !=. As you complete these problems, keep in mind De Morgan's laws. Here A and B represent integer variables.

  1. !(A != B)
  2. !((A <= B))
  3. !((A == 1) || (A == 4))
  4. !((A >= 4) && (B < 2))
  5. !((A <= 5) || (B == 6))
  6. !((A != 5) || (A == 5))
  7. !((A != 5) && (A == 5))
  8. !((A > B) || !(A == B))

Solution:
  1. (A == B)
  2. (A > B)
  3. (A != 1) && (A != 4)
  4. (A < 4) || (B >= 2)
  5. (A > 5) && (B != 6)
  6. (A == 5) && (A != 5) become false
  7. (A == 5) || (A != 5) becomes true
  8. (A <= B) && (A == B) becomes (A == B)

Instructor Responses: Response Analysis:

The following must be done out of class:

  1. In a first pass, mark and count the number of incorrect answers.
  2. 2. For each question that has a significant (your judgement call) of incorrect answers, do the following:
    1. Look through the answers to these questions.
    2. Place different incorrect answers in separate piles.
    3. Attempt to identify the nature of the most common errors that are made.
  3. Discuss in class these errors in class, using the common mistakes that you identified.

In-class feedback can be done by having students write their own answers, but caution must be taken to avoid embarassing or ridiculing a student for making mistakes.



Variant Uses of Activity:
Device-Enabled: Could be Enabled

Related Topics: