Sampling Flashcards
Target population
Every member of a group the researcher tends to study
Sample:
- Researchers are unable to conduct a research on a larger target population so researchers use sampling to sample smaller participants. The results of the sample are assumed to apply to all the members of the target population [generalisation]
Representative
- The sample used in the study should share characteristics with the members of the target population
Random sampling
Each member of the target population has a mathematically equal chance of being in the experiments sample
How to conduct random sampling
I] the researcher collects a tall lists of the entire target population
2J all names are then collected in e.g. Computer data base
3] using a random name generator
4) selects participants for the sample
Random sample [strengths AO3]
- Avoids research bias
Random sample [ weakness A03]
- Participants who are picked may produce an unrepresentative sample e.g. All male genders
- time-consuming to yet a full list of a large target population
Systematic sampling
Participants are chosen from a list of the target population. Every n (th) participant is chosen form the sample.
How to conduct systematic sample
- Researcher needs full list of target population
- researcher reads down the list selected every n (th) participants to form the sample
_ This process continues until the sample required is chosen
Systematic sample [strengths AO3]
- Avoids research bias
- less time consuming of there is an existing list of the target population
Systematic sample [ weakness AO3]
- May result in an unrepresentative sample [e.g. Too now members of one gender ]
- difficult to get a full list it target population is large
Opportunity sampling
-The researcher directly as available members of the target population to take part in the research
How to conduct an opportunity sampling
-research any members from within the population to take part in the research
-Any individuals who agreed to take part or to sample until the number of participant required is met
Opportunity sampling [A03] strengths
- Less time consuming as it is the fastest way to get a sample
- reducing cost
Opportunity sampling weaknesses [AO3]
-research bias- they may be an increase of research bias as a researchers are in control of which kind of participants he or she would want to ask for a study
-Opportunity samples are unlikely to be representative as a participants chosen are the type of people that research has easy to access to
Volunteer sampling
Participants offered to take part after finding up about the research e.g. this is likely after seeing an advert in a newspaper or online
How to conduct a volunteer sampling
-Advertisements are placed where they are likely to be seen by members of the target population
-Will include contact details and the researcher will enroll the volunteer into the sample
Volunteer sample [strengths [A03]
-advertisement can reach a large number of potential participants
_ An easy sample to collect as participants are putting themselves forward
Volunteer sample [weakness] [A03]
-The sample may not be generalisable to the target population due to volunteer bias types of people who volunteered to take part are likely to have different characteristics to the target population
Stratified sampling:
By selecting from within the sub group, the characteristics of participants within the sample are in the same proportion as found within the target population
How conduct stratified sampling
-sub group identified along with the proportion in the target population [e.g. age, gender]
_ random sampling is then used to select a number of participants required from within each stratum
Stratified sampling [ strengths A03]
-The sample is representative of the larger tiny population meaning the results are with the sample should be generalised to the target population
_ Avoids research buyers as a participants are randomly tracing from within each stratum
Stratified sampling weakness [A03]
-a limited amount of characteristics can be included in a stratified sample
_ may increase research as the researcher decides which strata are important
-Time consuming to establish strata and then randomly select from each stratum
