Psychology- Research Methods

What is volunteer sampling - Participants approach experimenters from adverts and the procedure is at the start to ensure consent Evaluation of volunteer sampling - Strengths - informed consent - large sample size Weaknesses - sample bias, those with more free time like older people or students are more likely to volunteer - Demand characteristics that also increase if paid What is opportunity sampling - Using participants close to them Evaluation of opportunity sampling - Strengths - easy to do - large sample Weaknesses - sample bias as they are surrounded by the same types of people What is random sampling - A sample that fairly represents a population because each member has an equal chance being chosen How is random sampling done - Names are put on equal sizes of paper and placed in a hat which has then shaken and selected until the amount is needed Evaluation of random sampling Strengths - Equal chance of selection - Variety of characteristics Weaknesses - Still may have a sample bias - Need a list of names What is systematic sampling - Every nth selected Evaluation of systematic sampling Strengths - No human choice - Variety of characteristics Weaknesses - Need a light if names - Still may get a sample bias What is stratified sampling - Working out the proportion of characteristics in the target population and match the target population to the sample Evaluation of stratified sampling Strengths - No sample Bias - Matched to target population Weaknesses - Time consuming - Small samples What is a population - Any person in the world What is a target population - People in the world interested in