Participant Selection

Question 1

What is random sampling?

Answer 1

Where all members from the population have an even chance of being chosen for the sample and are randomly selected.

Question 2

What is stratified sampling?

Answer 2

A method of sampling in a manner to eliminate possible confounding variables.

Participants are split up into ‘strata’ groups, which are groups based on variables like age, ethnicity, gender, IQ or years of completed education.

Stratified samples are drawn from the strata, representative of the occurrence in the population.

Question 3

What is convenience sampling?

Answer 3

Picking a sample from whoever is available at the time or nearby.

Question 4

Positives and negatives of random sampling?

Answer 4

Positives:
> Gives a representative sample
> Participant variables are evenly spread

Negatives:
> Difficult to achieve (esp. for larger populations)

Question 5

Positives and negatives of stratified sampling?

Answer 5

Positives:
> Eliminates the effect of the variable on which the sample is stratified

Negatives:
> Time consuming
> Expensive

Question 6

Positives and negatives of convenience sampling?

Answer 6

Positives:
> Quick, easy and cheap

Negatives:
> Sample will contain bias