Research Methods

• Aim


  A general expression of what the researcher intends to investigate
• Hypothesis


  A precise and operationalised statement about the assumed relationship between variables
• Directional Hypothesis


  States the direction of the predicted difference between two conditions or two groups of participants
• Non-directional Hypothesis


  Predicts simply that there is a difference between two conditions or two groups of participants without stating the direction of the difference
• Independent Variable


  Some event that either naturally varies or is directly manipulated by an experiment in order to test it's effect on another variable
• Dependent Variable


  A measurable outcome of the action of the independent variable in an experiment
• Operationalise


  Ensuring that variables are in a form that can be easily measured.
• Experimental method


  A researcher causes the independent variable to vary and records the effect of the IV on the dependent variable. The DV must be operationalised.
• Control


  (Refers to) The extent to which any variable is held constant or regulated by a researcher
• Extraneous Variables


  'Nuisance' variables that do not vary systematically with the IV. A researcher may control some of these.
• Confounding Variable


  Change systematically with the IV so we cannot be sure if any observed change in the DV is due to the CV or the IV. CVs must be controlled.
• Demand Characteristics


  Refers to any cue from the researcher or research situation that may reveal the aim of the study
• Investigator Effect


  Any effect of the investigator's behaviour on the outcome of the research (the DV)
• Randomisation


  The use of chance when designing investigations to control for the effects of bias
• Standardisation


  Using exactly the same formalised procedures for all ps in a research study
• Control groups


  Control groups are used for the purpose of setting a comparison. They act as a 'baseline' and help establish causation.
• Single Blind Design


  A ps doesn't know the aims of the study so that demand characteristics are reduced.
• Double Blind Design


  Both ps and researcher don't know the aims of the study to reduce demand characteristics and investigator effects.
• Participant Variables


  Individual differences. Differences among participants, overcome by a large sample size which dilutes any extremes
• Situational Variables


  People act differently in different situations. Time of day, Lab setting vs Natural setting
• Validity


  (Refers to) Whether an observed effect is a genuine one
• External Validity


  The degree to which a research finding can be generalised
• Ecological Validity


  A type of External Validity - generalising to other settings
• Population Validity


  A type of External Validity - generalising to other groups of people
• Temporal Validity


  A type of External Validity - generalising to other times/over time
• Cultural Validity


  A type of External Validity - generalising to other cultures
• Internal Validity


  The degree to which an observed effect was due to the experimental manipulation rather than other factors such as extraneous or confounding variables
• Mundane Realism


  (Refers to) How a study mirrors the real world. The research environment is realistic to the degree to which experiences encountered in the research environment will occur in the real world.
• Independent Groups


  One group does one condition the other group does the other condition. Each ps experiences one condition and they're randomly allocated to the groups.

  ✔️no order effects

  ✔️no demand characteristics

  ✖️more ps

  ✖️ps variables
• Repeated Measures


  Participants doing both conditions. To avoid order effects conditions should be counterbalanced. AB-BA

  ✔️less ps

  ✔️no ps variables

  ✖️order effects

  ✖️demand characteristics
• Matched Pairs


  Individuals matched up by characteristic (eg by IQ) and separated with one half of the pair in each group to overcome individual differences

  ✔️less ps variables

  ✔️no order effects

  ✖️more ps

  ✖️matching is not perfect
• Laboratory Experiment


  conducted in a lab, a highly controlled environment

  ✔️ highly controlled evs and dvs

  ✔️ can be easily replicated

  ✖️hard to generalise

  ✖️demand characteristics
• Field Experiment


  A natural setting.

  The researcher can control the IV.

  ✔️Higher external validity

  ✔️No demand characteristics bc ps don't know they are taking part in a study

  ✖️Difficult to control CVs

  ✖️Ethical issues bc ps don't know they are taking part in a study
• Natural Experiment


  IV cannot be manipulated because it naturally exists

  DV naturally occurring

  ✔️an ethical option

  ✔️high external validity

  ✖️natural events occur rarely

  ✖️ps are not randomly allocated so there is a chance of ps variables
• Quasi-Experiment


  The IV is based on existing differences (eg age or gender) so can't be controlled

  DV naturally occurring

  ✔️High control

  ✔️Comparisons can be made btwn ppl (eg ppl with and without autism)

  ✖️Ps are not randomly allocated so chance of ps variables

  ✖️Causal relationships not demonstrated
• Population


  The large group of ppl that a researcher is interested in studying
• Sample


  It is usually not possible to include all members of the population in the study, so a smaller group is selected - the sample.
• Generalisation


  The sample that is drawn should be representative of the population so generalisations can be made
• Bias


  The majority of samples are biased in that certain groups may be over or under-represented
• Opportunity Sample


  Recruit people who are most convenient or most available (eg people walking by you in the street or students at school)

  ✔️Easiest method (use the first suitable participants you find).

  ✔️Less time to locate your samples

  ✖️Inevitably biased (sample drawn from small part of population)