research methods

• define an aim

  identifies the purpose of the study
• define a hypothesis

  a testable statement. what the researcher believes to be true about the target population.
• define directional hypothesis

  predicts in which direction the results are likely to go
• define non-directional hypothesis

  researcher expects the IV will affect the DV but not sure how
• define null hypothesis

  the IV has no affect on the DV
• define IV

  Independent variable. The thing you change
• define DV

  dependent variable. the thing you measure
• define extraneous variable

  anything that is not the independent variable that may affect the DV
• define confounding variable

  a type of extraneous variable that masks the true source of the change in DV. it appears as though the IV caused the change in DV, but really it was the CV.
• define operationalisation

  defining a concept so it can be measured
• define demand characteristics

  participants change their behaviour to meet the aim of the study
• define investigator effects

  researcher behaviour affects participant's behaviour
• define random allocation - control

  participants randomly put into different conditions
• define counterbalancing - control

  half of the participants do condition A then B. the other half do

  condition B then A
• define randomisation - control

  chance methods when designing experiment to reduce bias
• define standardisation - control

  making the experiment exactly the same for every participant to reduce bias
• define LAB - types of experiments

  • artificial environment
  • researcher manipulates the IV and records the DV
• LAB experiments (strengths)

  • high control over extraneous variables
  • easy to replicate
• LAB experiments (limits)

  • demand characteristics
  • lacks mundane realism / external validity
  • investigator effects
• define FIELD - types of experiments

  • natural environment
  • researcher manipulates the IV and records the DV
• FIELD experiments (strengths)

  • higher mundane realism
  • easier to generalise results = external validity
• FIELD experiments (limits)

  • can't control all variables
  • time consuming
• define NATURAL - types of experiments

  • researcher observes IV and records DV
  • IV is naturally occurring = something happened to the PPs that would have happened anyway
• NATURAL experiments (strengths)

  • less chance of demand characteristics
  • more ethical = used when unethical / impossible to manipulate in a lab or field experiment.
• NATURAL experiments (limits)

  • IV is not controlled
  • no control over PP group allocation
  • can be unethical = lacks full informed consent
• define QUASI - type of experiments

  • usually conducted in a lab
  • IV is naturally occurring but based on a pre-existing difference.
  • e.g. age, gender, autism
• define reliability

  how consistent a study or measuring device is. a study is reliable if it can produce similar results when the study is replicated
• define validity

  the extent a study measures what it claims to. when a study has high control of extraneous variables, it is valid.
• define internal validity

  when the results can be directly linked to the manipulation of the IV
• define external validity

  when the results can be generalised outside of the experimental setting
• define population validity

  when the results can be generalised to a wider population
• define ecological validity

  when the results can be generalised to different places or environments
• outline independent groups - exp design

  • different participants in each condition with different IVs
  • groups are randomly allocated or naturally occurring
  • participants only take part in one condition each
• outline repeated measures - exp design

  participants do all conditions
• outline matched pairs - exp design

  • participants matched in pairs then split into different conditions
  • e.g. top 2 IQs in different conditions
• outline single blind technique - exp design

  participant is not told the true aim or the condition they're in = unethical
• define double blind technique - exp design

  neither participant or researcher knows the true aim or the condition they're in = unethical
• independent groups STRENGTHS - exp design

  • less chance of demand characteristics = PPs only do one condition so less chance of guessing the aim
• independent groups LIMITS - exp design

  • more participants needed = more time consuming
  • differences in results may be due to individual differences rather than manipulation of IV because groups are uneven
• repeated measures STRENGTHS - exp design

  • fewer participants needed = less time consuming
  • same PPs in each condition = no participant variables
  • counter balancing = control order effects