AO3 - Sampling Techniques

• One strength of random sampling is that it is potentially unbiased as everyone in the target population has an equal chance of being selected for the study (AO2). This means any extraneous variables will be equally divided between the different groups. This increases the internal validity.
• A weakness of random sampling is that it is very time consuming because it takes time and can be difficult collecting all the names of participants to take part in the study (AO2) and it is not guaranteed participants would want to take part in the research.
• A strength of systematic sampling is that it avoids researcher bias as the researcher has no influence over who is chosen to take part in the study (AO2) as it is objective once the system to select participant is established.
• A weakness of systematic sampling is that the sample may not be representative as not everyone has an equal chance of being picked therefore it is difficult to generalise to the target population (AO2). Moreover, creating the system and collecting names could be time consuming and difficult for the researcher.
• A strength of stratified sampling is that it is most representative sample as is it accurately reflects the make-up of the target population (AO2) in the correct proportions/amounts meaning findings can be generalised to the target population.
• A weakness of stratified sampling is that it is very time consuming because it takes time working out the proportions of participants needed (AO2) and it is not guaranteed participants would consent to take part.
• A strength of opportunity sampling is that it is very quick, easy and less money is required as as you choose who is available at the time for your sample (AO2) unlike random sampling which takes a long time to identify everyone in the target population and make a list of all names.
• A weakness of opportunity sampling is that it may not be representative of the target population, those picked by an opportunity sample are present in the same place at the same time, doing similar things, (AO2) therefore they may have similar personalities (e.g. AO2), making it difficult to generalise findings to the wider population.
• A strength of volunteer sampling is that it is very quick, easy and cheap to conduct as all that is required is to place an advert for the study in a place the target population may be (AO2) and wait for participants to volunteer to take part in the study (number) unlike random sampling which takes time to place names into a hat and give the population an equal chance of being picked.
• A weakness of volunteer sampling is that the sample may be bias/not representative as only a certain type of personality (AO2, e.g. extroverts) will volunteer (AO2) therefore difficult to generalise to the target population.