Sampling Techniques

Question 1

Random sample and how ?

Answer 1

Every person in target population has an equal chance of being selected

List all target population
Write on equal size paper put in hat
Select number you want from hat without looking

Question 2

Ao3 strength random sample

Answer 2

Potentially unbiased as target population have equal chance of being selected

Means extraneous variables equally divided between different groups , increasing internal validity

Question 3

Ao3 weakness random sampling

Answer 3

Time consuming , takes time collecting all names of participants

Not guaranteed participants would want to take part in research

Question 4

Systematic sample and how ?

Answer 4

‘System” is applied to select participants

Create sample frame to organise participants eg put target population in alphabetical order

Decide on system eg very 5 th or 10 th person chosen until there are enough participants for the sample

Question 5

Ao3 strength systematic sample

Answer 5

Avoids researched bias , as there is no influence over who is chosen to take part

As it’s objective once system is select ppt is selected

Question 6

Ao3 weakenss systematic sample

Answer 6

May not be representative as not everyone has earned an equal chance of being picked

Thus difficult to generalise to target population

Creating a system and collecting names could be time consuming and difficult for the researcher

Question 7

Opportunity sample and how?

Answer 7

Being there at that moment in time

Go somewhere here you’ll have access to population you want to study

Ask first 30 ppts who are there at that moment in time if they’ll take part

Question 8

Ao3 strength opportunity sample

Answer 8

Very quick easy and less money required as you chose who is available at the time for your sample

Unlike random sampling which takes a long time to identify everyone in target population and make list of all names

Question 9

Ao3 weakness opportunity sample

Answer 9

May not be representative of target population

As those picked are present in the same place, same time doing similar things

Thus they may have similar personalities making it difficult to generalise findings to wider population

Question 10

Volunteer sample and how?

Answer 10

‘Self selected’ people volunteer to be ppts

Place and advert where target population will see it and wait for the first 30 people to reply

Question 11

Ao3 strength volunteer sample

Answer 11

Very quick,easy and cheap as all that is required is to place an advert where target population is

And wait for a volunteer to take part in the study

Unlike random sampling which takes time to place names into a hat and give population an equal chance of being picked

Question 12

Ao3 weakness volunteer sample

Answer 12

Sample bias as only certain personalities more likely to please the researcher will volunteer

Thus difficult to generalise to the target population

Question 13

Stratified sample and How ?

Answer 13

Advanced way of sampling,make -up sampling reflects proportions of certain sub - groups in target population

Percentage is given:

Sample size wanted / 100 x percentage of sub group

Percentage is not given:

Sample size of wanted / target population x sub group size

Question 14

Ao3 strength stratified sample

Answer 14

Most representative sample

Accurately reflects make up of target population

In correct proportions meaning findings

can be generalised to target population

Question 15

Ao3 weakness stratified sample

Answer 15

Very time consuming

Takes time working out proportions of ppts needed

Not guaranteed ppts would consent to take part