Session 3 - Frequency Distributions and Summary Statistics

Question 1

Types of Categorical Data

Answer 1

Nominal - categories not ordered, eg eye colour
Ordinal - categories have a natural order eg stage I,II,III,IV

Question 2

Continuous Data

Answer 2

Numerical counts or measurements
Integers - eg no of children
Any number in a range - eg body weight

Question 3

Categorical Variables - summary statistics

Answer 3

Frequency, Relative Frequency (%), Frequency distribution (table)
Illustrate with bar chart

Question 4

Ordered Categorical Variables - summary statistics

Answer 4

Cumulative Frequency
Relative Cumulative frequency

Question 5

Continuous Variables - summary statistics list

Answer 5

Depict using histogram
Or Box and Whisker (IQR, Median)
Mean
Median (less affected by outliers than mean)
Mode
Variance
Standard Deviation
Percentiles
Quartiles, IQR

Question 6

Central tendency for positively skewed data

Answer 6

Tail to positive direction
Mode<Median<Mean

Question 7

Variance

Answer 7

Average of squared differences from the mean

Question 8

Standard Deviation

Answer 8

Average difference from the mean (square root of variance)

Question 9

Data are collected as…

Answer 9

Variables, which van be of categorical or continuous nature