Types of sampling and data

Question 1

Random?

Answer 1

All members of the target population have an equal chance of being selected to participate

Question 2

Random strength?

Answer 2

Investigator has no control over who is picked so bias is avoided

Question 3

Random weakness?

Answer 3

Probability relating to mathematical laws suggests that the sample should be representative however there is still a chance that it will not be

Question 4

Systematic?

Answer 4

A mathematical selection of participants where the population size is divided by the sample size to dictate which participants are chosen for the sample- every nth name

Question 5

Systematic strength?

Answer 5

The only input the researcher has is choosing the sample size- avoids investigator bias

Question 6

Systematic weakness?

Answer 6

Still a chance that the sample will not be representative - cannot be generalised

Question 7

Stratified?

Answer 7

Ensures that the key characteristics of the population are represented in the same proportion of the sample

Question 8

Strength of stratified?

Answer 8

Avoids investigator bias and allows for the results to be generalised as the sample is representative

Question 9

Weakness stratified?

Answer 9

If all key characteristics are not identified then the sample is not representative

Question 10

Strength of opportunity?

Answer 10

Straight forward selection, less time consuming

Question 11

Weakness of opportunity?

Answer 11

The investigator may consciously or subconsciously show bias in the sample selection thus limiting generalisation

Question 12

Time sampling?

Answer 12

Time sampling is a method of sampling behaviour in an observation study and is where an observer records behaviour at prescribed intervals. For example, every 10 seconds.

Question 13

Event sampling?

Answer 13

Event sampling is used to sample behaviour in observational research. It is where an observer records the number of times a certain behaviour occurs.

Question 14

What is primary data?

Answer 14

Primary data is collected first hand by the researcher for a specific research purpose.

Question 15

Secondary data?

Answer 15

When a researchers uses secondary data, this means that someone else has already collected the information, for a different purpose and the information has been stored on record for use by other researchers.

Question 16

Disadvantage of primary data?

Answer 16

A disadvantage is that it is expensive to obtain because each researcher or research team has to start from the beginning of a study and follow the whole study through, finding participants, organising materials and running the study.