Research methods

• What is an aim

  A general statement of the purpose of research
• what is a null hypothesis

  predicts no change between the conditions
• what is a directional hypothesis 


  predicts there will be a change and predicts the

  direction

  Condition 1 will do change word in the DV compared to condition 2
• what is a non directional hypothesis 


  predicts there will be a change but not the

  direction

  There will be a difference in x as a result of y
• what is a population 


  this is the group of people the researcher is interested in
• what is a sample 


  A smaller group selected from the target population to carry

  out research on
• what is volunteer sampling

  participants volunteer to be a part of the study
• strength of volunteer sampling

  • convenient
  • informed consent
• weaknesses of volunteer sampling

  • all people who volunteer may have similar characteristics therefore unrepresentative sample - leads to bias
• what is opportunity sampling 


  this involves simply selecting people who are available at that time
• benefits of opportunity sampling

  • quick
  • convenient
  • cheap
• limitations of opportunity sampling

  • unrepresentative - all people picked may have similar characteristics
  • bias - researchers are likely to pick people that might help the study
• what is random sampling

  This method gives every member of the target group an equal chance of being selected for the sample
• how do you randomly sample

  assigning a number to each member, and then selecting one at random random using a number generator
• benefits of random sampling

  • Unbiased Sample
• limitations of random sampling

  • time consuming
• what is stratified sampling 


  dividing the target population into important subcategories. selecting members in proportion that they occur in the population
• strengths of a stratified sample

  • representative sample
• limitations of stratified sample

  • time consuming
• what is systematic sampling

  The required elements are chosen at regular intervals from an ordered list
• what is sampling bias

  occurs when some members of a population are systematically more likely to be selected in a sample than others
• what is a pilot study

  a smaller version of a proposed study and researchers frequently conduct these to refine the methodology / strengthen future study design.
• what are the three types of experimental design

  • repeated measure
  • independent groups
  • matched pairs
• what is a repeated measures design 


  Each participant is tested in both conditionsParticipants are being tested against themselves
• evaluation of repeated measure design

  +uses fewer participants

  +individual differences eliminated

  -order effects

  -boredom effects

  -demand characteristics

  -
• what is order effects

  Order effects can occur in a repeated measures design and refers to how the positioning of tasks influences the outcome
• what is boredom effects 


  People may perform worse in a second condition due to boredom
• what is a matched pairs experimental design

  where pairs of participants are matched in terms of key variables, such as age and IQ. One member of each pair is then placed into the experimental group and the other member into the control group.
• how do you assign matched pairs

  1.Identify the variable to match participants on (RELEVANT TO THE RESEARCH)2.Test all participants on the chosen variable: you need to tellexaminer how you would do this3.Analyse test results, and then match pairs based on having similar scores- e.g. putting them into rank order and taking the top 2 as first pair4.Randomly assign one person from each pair to each condition
• evaluation of matched pairs

  +no order effects

  +no boredom effects

  -time consuming

  -costly
• what is independent group design


  Different participants in each conditionparticipants only experience one condition
• evaluation of independent groups design

  +no order effects

  +no boredom effects

  +reduced chance of demand characteristics

  -more participants needed

  -
• what is operationalising 


  turning abstract concepts into measurable observations.
• what is an independent variable 


  the aspect of the research that is changed by the researcher
• what is a dependent measure


  This is some aspect of behaviour that is going to be measured or assessed in order to decide whether or not the IV caused a change in behaviour
• what are control variables

  The variable you keep the same to ensure the research is replicable and consistent between conditions so you can compare conditions
• what are participant variables

  Participant variables (also known as subject variables) are the differing individual characteristics of participants in an experiment. Participant variables can be considered extraneous variables because they are variables that can influence the results of an experiment but that the experimenter is not studying.
• what are situational variables 


  Situational Variables are factors in the environment that can unintentionally affect the results of a study. Such variables include noise, temperature, odors, and lighting. Situational variables can be considered extraneous variables because they are variables that can influence the results of an experiment but that the experimenter is not studying.
• what is standardisation 


  Keeping everything the same for all participants (except the IV) so that the investigation is fair standardised procedures should be used for the collection of data
• what are investigator effects

  When the researcher's behaviour and characteristics may change / impact the results of an investigation.