Distributions

Question 1

What should distibution be like if a test has an appropriate difficulty level?

Answer 1

• Normal distribution curve
• A symmetrical bell-shaped frequency distribution
• Mean, median, and mode are all at the mid-point
• This is because as scores increase/decrease from the mean there will be fewer people who score very high or very low as most people should score averagely

Question 2

What would distribution be like if the test was too easy?

Answer 2

• Negative skewed distribution
• Non-symmetrical frequency distibution
• The mean skews distribution to the left because it’s affected by lower scores (takes all values into account)
• The mode is the highest point and furthest right
• This is because high scores are most frequent as the exam was too easy
• mode>median>mean (in terms of values)

Question 3

What would distribution look like if the test was too hard?

Answer 3

• Positive skewed distribution
• Non-symmetrical frequency distribution
• Mean skews distribution to the right as it is affected by high scores (takes all scores into account)
• Mode is the highest point and furthest left
• This is because low scores are most frequent as the test was too difficult
• mean>median>mode (in terms of values)