Exercises: Types of Data
Question 2.1
What types of variable are the following (nominal, ordinal, metric discrete or metric continuous)?
- Number of teeth
- Age
- Age last birthday (in years)
- Has patient visited their dentist in the last year
- Social class
- Pocket depth
- Hardness of filling material
- Colour of filling material
- Type of radiograph
- Calcium:phosphorus ratio in teeth
- Severity of gum disease
Question 2.2
The following table is en extract from a paper looking at caries prevalence amongst children in Wick, Scotland. What types of variable are represented here?
(dmft = decayed, missing and filled teeth total)
Variable | |
n | 106 |
mean | |
dmft | 2.63 |
% caries free | 27.4% |
Decayed/filled teeth | 2.39 |
Extracted teeth | 0.75 |
proportion | |
Social class I & II | 15.0% |
Social class III | 42.5% |
Social class IV & V | 30.2% |
Social class unknown | 12.3% |