Sampling Techniques

Question 1

What is sampling?

Answer 1

How the researcher gets the sample to include within the research, aiming to obtain a sample that represents a target population

Question 2

What is a target population?

Answer 2

A group of people that the researcher is interest in, from whom a sample is drawn and about whom a generalisations can be made

Question 3

What is random sampling?

Answer 3

A sample produced by using a random techniques so every member of the target population has an equal chance of being tested

Question 4

What are the two ways random sampling can be done?

Answer 4

• Lottery method: all names in a lottery hat and select the number of names required
• Random number generator: assign each person a number. Using the generator, participants are selected until you have the desired sample

Question 5

What are advantages of random sampling?

Answer 5

• There’s little research input and each person has an equal chance of being selected so it isn’t affected by researcher bias
• It’s quicker to conduct than other techniques

Question 6

What are disadvantages of random sampling?

Answer 6

• There’s chance that the sample obtained doesn’t represent the target population
• It requires a full list of the target population

Question 7

What is systematic sampling?

Answer 7

• Uses a predetermined system to select participants e.g. every nth person
• Requires an alphabetically ordered list of individuals and a random generator to get the nth term. Then select every nth term person until sample is complete

Question 8

What is an advantage of systematic sampling?

Answer 8

Little research bias as participants are selected using an objective system and each person has an equal chance of being selected

Question 9

What are disadvantages of systematic sampling?

Answer 9

• May not be always representative as the sample is left to chance
• It takes time and resources to do as it requires a full list of the target population to be obtained and ordered

Question 10

What is stratified sampling?

Answer 10

• The subgroups (strata) within a population are identified, who have a key characteristic which should be present in the final sample
• Participants are then obtained from each strata in proportion to their occurrence in the population
• Selection from the strata is random

Question 11

What are advantages of stratified sampling?

Answer 11

• It produces the most representative sample as it’s designed to accurately reflect the composition so generalisations of the findings are possible
• There’s little researcher bias as it still uses randomisaton

Question 12

What is a disadvantages of stratified sampling?

Answer 12

It may be impractical as it requires a full list of the population to be obtained and it here must be ensured that a key characteristic present in the population is selected across the strata, so it’s time-consuming