Psychology: Descriptive Statistics

Question 1

What are the 3 measures of Central Tendency?

Answer 1

Mean
Median
Mode

Question 2

How to calculate mean, median and mode?

Answer 2

Mean - Add and divide
Median - Middle
Mode - See the most

Question 3

What is a strength and limitation of using the mean?

Answer 3

Strength:
All scores are taken into account therefore more representative of all the date
Limitation:
It can be skewed by extreme scores

Question 4

What is a strength and limitation of using the mode?

Answer 4

Strength:
Only measure that can be used on all types of data
Limitation:
There may be several modes. Ignore all other scores.

Question 5

What is a strength and limitation of using the median?

Answer 5

Strength:
Not skewed by extreme scores
Limitation:
It does not take into account all scores

Question 6

What do you use Mean, Mode and Median?

Answer 6

Mean - no extreme scores
Median - 1 or more extreme scores
Mode - can be used on any data but usually used when data is categorical

Question 7

What is a meant by a normal distribution?

Answer 7

Mean, mode and median are roughly the same

Question 8

What is meant by positive skew?

Answer 8

The mode (the most frequent score) is lower than the mean

Question 9

What is meant by a negative skew?

Answer 9

When the mode is higher than the median.

Question 10

What are 2 measures of dispersion?

Answer 10

Range and Standard Deviation

Question 11

What is Standard Deviation better to use than range?

Answer 11

Standard Deviation is a better measure of distribution as it takes in account all scores not just the highest and lowest

Question 12

What does a larger Standard Deviation show?

Answer 12

The larger the SD the greater the variation or spread of scores from the mean

Question 13

What does a low Standard Deviation show?

Answer 13

A low SD would suggest there is little variation in scores - they are clustered around the mean.