CIE AS psychology 9990

• Theory


  A form of fact-based ideas that describe a specific topic
• Hypothesis


  A testable prediction, created from a theory (has 2 types)
• Null hypothesis


  Describes no relationship between the IV and the DV
• One-tailed/directional hypothesis (alternative hypothesis)


  A statement that specifies the kind of difference between the IV and DV in terms of the effect or relationship between them
• Two-tailed/non-directional hypothesis (alternative hypothesis)


  A statement that does not specify the kind of difference between the IV and DV (shows the link between variables but does not explain it and won't predict in which direction it goes)
• Dependent variable


  Variable that is measured
• Independent variable


  Variable that is changed/manipulated
• Cause and effect


  IV causes an effect on the DV
• Levels of IVs


  Different ways an experimenter can change or manipulate the IV (the amount of conditions there are)
• Operationalisation of variables


  How a variable can be measured or observed, through operationalisation you can systematically collect data on variables that aren't directly observable
• Examples of operationalisation


  • Ability to cook-rate dishes from 1 to 10
  • Skills of a footballer-see who can do the most skills
  • Level of fitness-the amount of time the participants can last doing exercises
  • The effect of age on susceptibility to false memories-(age=IV) create categories for each age group (false memories=DV) counting the number of details remembered about a false memory
• Standardisation of a procedure

  Controlled variables must stay the same so that the research can be replicated so participants should all be given the same information and instructions
• Participant variables


  Individual differences between participants which can affect the results of a study
• Situational variables


  Any aspect of the environment that could impact the participants' behaviour and therefore the results
• Uncontrolled variables


  Factors that aren't measured or controlled by the researcher which can affect the DV (e.g. temperature of the room or noise levels)
• Extraneous variables


  Any variable that is not the IV which can effect the DV
• Order effects (EV)


  When the order of the conditions affects the result of an experiment, they occur in a repeated measures design, there are two kinds: practice & fatigue effects
• Order effects-counterbalancing


  Switching up the order in which the participant groups perform tasks
• Order effects-randomisation/random allocation


  Randomly assigning/allocating participants to different conditions which helps to remove researcher bias along with participant variables
• Ways to control EVs

  • Single-blind testing - info withheld from participants
  • Double-blind testing - info withheld from participants & researchers
  • Deception - misleading or lying to participants about the aims of the study
• Demand characteristics


  Features of the experimental situation which give away the aims of the experiment, they can cause participants to change their behaviour
• Social desirability


  Participants changing their behaviour to be more socially desirable (be more liked)
• Experimental designs (3 types)

  • Independent measures
  • Repeated measures
  • Matched pairs
• Independent measures design


  Participants take part in only 1 level of the design
• Independent measures design


  • Demand characteristics are unlikely to effect the study
  • No order effects
  • Participant variables are likely to be present
  • More participants needed
• Repeated measures design


  All participants take part in all levels
• Repeated measures design


  • Less participant variables
  • Fewer participants needed
  • Order effects may distort the results
  • Greater exposure to demand characteristics
• Matched pairs design


  Participants are arranged into pairs and perform different levels of IV
• Matched pairs design


  • Demand characteristics are less likely to effect the study
  • Participant variables are less likely
  • Sample size may be small
  • Matching criteria has to be chosen in advance
• Ecological validity


  Refers to the extent to which findings from a study can be generalised to other situations and settings
• Internal validity


  Refers to the extent to which the researcher is testing what they claim to be testing (it looks at how strong the relationship is between the cause and effect)
• Reliability


  Consistency and stability of a measurement in a study
• Generalisability


  The extent to which you can apply the findings from a study to the wider population
• Types of experiment (4 types)

  • Field
  • Quasi
  • Laboratory
  • Natural experiments
• Laboratory experiment


  Conducted in a controlled environment, researchers manipulate/change the IVs and measure the effects on the DVs
• Laboratory experimentcharacteristics


  • High control over variables
  • Easier to replicate and standardise procedures
  • The artificial setting may lack ecological validity
  • Demand characteristics may influence participant behaviour
• Field experiment


  Conducted in real-world settings, researchers manipulate IVs and measure the effects on the DVs
• Field experiment


  • Participants' behaviour is likely to be more natural
  • Demand characteristics are less likely to affect the study
  • Less control over EVs
  • Harder to replicate as real-world settings vary
• Quasi experiment


  Experiment without random assignment of participants to conditions, researchers take advantage of pre-existing groups or conditions, researchers manipulate IVs and measure the effects on the DVs
• Quasi experiment


  • Can be used when random assignment is unavailable or is unethical
  • Allows researchers to study naturally occurring groups or conditions
  • Potential confounding variables may influence results
  • Lack of random assignment limits causal conditions