Data can come in two forms:
- Qualitative (words)
- Quantitative (numbers)
Quantitative data can be:
- Discrete i.e. can only take certain values – e.g. the number of children in a class
- Continuous i.e. can take any value in a range – e.g. weight
To collect quantitative data you need to group it into classes. Discrete data has “gaps” between classes (e.g. 1-2 children, 3-4 children etc). Continuous data does not..and as such is often written as inequalities (e.g. 30lbs < weight ≤ 50lbs, 50lbs < weight ≤ 70lbs etc).
You might be asked whether a questionnaire is good or bad. For a questionnaire to be a good one the questions must be:
- Clear and easy to understand
- Easy to answer
- Not misleading or biased
- Easy to analyse
So avoid open ended questions, questions with possible answers like “a little bit” which are open to interpretation, and questions that suggest an answer.