Descripitive Statistics - Measures of Central Tendency

Descriptive statistics

The use of graphs, tables and summary statistics to identify trends and analyse sets of data

Measures of central tendency

The general term for any measure of the average value in a set of data

What is the mean?

The average score of a data set

How do you calculate the mean?

Adding up all the values in a data set and dividing this figure by the total number of values there are

What are advantages of the mean?

Most sensitive, takes into account every value. Provides a representative score (most reliable)

What are disadvantages of the mean?

Sensitive to extreme outliers and the mean score may not be represented in the data set

Median

Middle value in a set of data when scores are arranged from lowest to highest

What are the advantages of the median?

Not affected by extreme scores. Easy to calculate, less sensitive as not all of the scores are included

What are the disadvantages of the median?

Doesn’t represent a typical average, doesn’t include all of the data. Doesn’t account for extreme scores, makes it less reliable

Mode

Most frequently occurring score/value within a data set

What are the advantages of the mode?

Not affected by extreme values. Useful for analysis of qualitative data

What are the disadvantages of the mode?

May be unrepresentative, isn’t close to the average and causes a lack of validity