Sampling and Experimental Design

View mindmap
  • Research Methods - Scientific Processes
    • Experimental Design
      • Independent Groups
        • participants are allocated to different groups where each group represents an experimental condition
        • eliminates order effects and participants are less likely to guess the aim
        • participant variables can influence the results and it is less economical than repeated measures
      • Repeated Measures
        • all participants take part in all conditions
        • fewer participants are needed and participants variables are controlled
        • order effects (boredom / fatigue and practice) could alter results and participants are more likely to guess the aim
      • Matched Pairs
        • pairs of participants are matched on some variable that may affect the DV and then split into different conditions
        • order effects eliminated and demand characteristic reduced
    • Sampling Methods
      • Random
        • all members of the target population have an equal chance of being selected
        • free from researcher bias
        • difficult and time consuming to obtain list of whole target population
        • may produce an unrepresentative sample
      • Stratified
        • the composition of the sample reflects that of the population considering the proportion of particular subgroups
        • avoids researcher bias
        • creates a representative samples that accurately reflects the population
        • it is difficult to truly represent all subgroups
      • Oppurtinity
        • selecting people that are available and willing at the time
        • very unrepresentative and so not generalisable
        • it is very convenient for the researcher
        • subject to researcher bias
      • Systematic
        • when every Nth member of the target population is selected
        • avoids researcher bias
        • usually fairly representative
        • can be time consuming as a sampling frame needs to be produced
      • Volunteer
        • really easy and requires minimal input from the researcher
        • less time consuming compared to other methods
        • volunteer bias becomes an issue producing an unrepresentative sample
        • involves people selecting themselves to take part in a study


No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Research methods and techniques resources »