1. Questionnaire
Sampling and Terms

2. Terms

3. Terms Population Bias Sample Sampling frame Representative
the whole group being studied
Sample
A carefully selected subset of the population
Representative
A sample that bears similar characteristics and proportions to the population
Bias
Relates to the method used to select the sample. Unbiased methods give all elements of population equal chance of selection.
Sampling frame
The list that gives information about the population – the source material for selecting the sample.

4. Population: Sample: a set which includes all measurements of interest
to the researcher
Sample:
A subset of the population

5. Why sampling? Get information about large populations Less costs
Less field time
More accuracy i.e. Can Do A Better Job of Data Collection
When it’s impossible to study the whole population

6. Simple random sampling

7. Systematic sampling
Always picking a person at random based on the position of their name on a list.
Start with a random number for the first selection point.
Divide the total number in the set by the sample size you wish to use in your evaluation
For example:
If you want a sample of 30 and you have 180 pieces of data, 180/30 = 6
- pick every 6th person in the list

8. Systematic sampling

9. Sampling Sampling Method How Advantages Disadvantages Simple Random
Each member of the population is assigned a random number. Random numbers are drawn
Each member of the population has an equal chance of being chosen. Is representative and unbiased
Time-consuming and expensive
Systematic
The population is listed and then a sample is chosen using a pattern such as choosing every kth member
Quicker and cheaper than random sampling
If there is a repeating pattern in the population the sample may not be representative. The level of sampling errors cannot be determined
Sampling of Volunteers
People ask to be part of the sample
Very quick and cheap
Biased and not representative

10. Precision
Cost

11. Circles – representative?
Click on flower for sample selection app

12. Design I have chosen to put the questions in this order because…..
In this section comment of the order of the questions and on the purpose of each question.
Set up a table to help set out your work.
Question
Type of Question
Purpose/reason
Gender M/F?
Multiple choice
There are only two options and it will be quick and easy for the participant to respond. It will also be easy for me to collate how many males and females once the survey’s are returned.
2.  3.
I have chosen to put the questions in this order because…..

13. Pilot survey
In this section you will need to provide the drafted questions to another student.
You will give written feedback to the writer of the questionnaire.
Here is an example of the kind of feedback you could give.
Question Number
Feedback 1
This is a good simple question to start with and I agree multi-choice seems like the obvious choice. 2
I noticed you only gave four options for this question and I’m wondering if you need to consider….. 3
This open ended question is quite early in the questionnaire and I wonder if you could be left to the end. I also think you will get a vast range of answers that will be difficult to compile once all the survey’s are returned.