Psychology - Research Methods

• Experimental method


  conducting experiment with aims and a hypothesis to reach to a scientifc conclusion
• What is an aim?


  an idea of what the study is trying to achieve

  e.g see if stress effects our memory
• What is a hypothesis


  predicts what we expect to find
• What is an independant and dependant variable


  IV= a variable that the researcher chnages, DP= what the researcher is measuring to see if Iv has affected iot.
• what is the difference between a directional and non- directional hypothesis


  Directional = states the direction the results will go in, whether changes are greater or lesser, positive or negative. whereas non directional just states that one factor will effect another ;that there is a difference.
• what is the difference between a null hypothesis and alternative hypothesis


  null hypothesis states theres no relationship between the two variables being studied , whereas alternative hypothesis theres a relationship between two variabes studied. ( one has an effect on the other )
• verbal fluency


  the ability to talk without pausing or stopping
• what are extraneous variables


  Additional or unwanted variables that effect the experiment other the IV
• What are confounding variables?


  Extraneous variables that change systematically with IV so aren't recognised if they impact DP e.g time changes with IV
• What are demand characteristics?


  Cue from researchers or research situation that participant interprets as revealing the aim of investigation and result in a change in their behaviour
• What are investigator effects?


  Any effect of the investigators behaviour on the research outcome
• Standardisation


  All participants should experiences the same environment, information and experience = minimises chance of extraneous variables
• randomisation


  Use of chance method to control the effects of bias when designing investigations. e.g particpant allocation
• experimental design


  Experiment must at least two conditions but they can be arranged in variety of ways
• Repeated meaures design

  Same participants take part in both conditions
• what are the limitations of repeated meaures


  - order effects : order they do tasks may effect performance (may do better or do worse due to fatigue )

  - Gives participant opportunity to practice task and may makes them bored/tired

  - participant may figure out aim of study ( demand characteristics) - all reduce validity
• how does couterbalancing solve the limitaion of repeated mesaures

  It ensures each condition is tested whether first or second in equal amounts reducing order effects
• independant group design


  two groups; Only one group does each condition
• what are the problems with indpendant group design

  - Natural variation between participants characteristics (variables ) act as EVs and CVs so may affect the DV measurements = reduced valdiity

  - less economical; need twice as many participants = more expensive
• how does random allocation solve the problems with indpendant group design


  It theoretically distributes participants evenly
• matched participants design


  When participants are matched based on Similarities, participant variables that matter for the experiment.
• what are the issues with matched participants design


  - Time consuming

  - expensive ( as theres more participants )

  - exact match not possible ; cant control /address all participant variables

  - no possible to control all participant variables
• how do psycholgist solve the issues with matched participants


  - Restrict the number of variables to match participants on

  - conduct a pilot study to consider key variables
• name two advantages of independant group studies


  - participants will not guess aim (only tested once) = increased validity

  - no order effect ( can't practice become bored of tired ) = CV controlled
• name two advanatges of repeated measures


  - controls participant variables ( same person so same characteristics )

  - fewer participants ( cheaper, less time spent recruiting )
• name two disadvanatges to independant group design

  - Participant variables ; participant in two groups have different characteristics which acts as Evs/Cvs = reduce validity

  - less economical : need twice as may participants = more time recruiting which is expensive
• explain two disadvanatages to matched pairs


  - Matching is not perfect ( can be time consuming and can't control all relevant variables )

  - more participants ( need twice as many participants = expensive )
• explain two disadvantages of repeated meaures


  - order effects are a problem

  - participant guess aims ( may guess, deceases validity )
• explain two adv of matched pairs


  - Participant variables controlled ( matched on variables relevant to experiment )

  - no order effects ( only tested once )

  
  

  Both enhance validity
• whats an laboratory experiment


  Experiment conducted in a highly controlled environment, every variable (EV and CV ) controlled.

  - Researcher manipulated IV (stimulus) and records response (DV)
• whats an field experiment


  IV is manipulated in a more natural, everyday setting and DV is recorded

  
  

  E.g public ( researcher goes to participants )
• whats an natural experiment


  - Researcher takes advantages of a naturally occurring IV ( e.g age/natural disaster )

  - dosent manipulate IV but records DV dv could be natural e.g exam results )

  (E.g takes places in two different cultures and analyses parenting styles)
• What's a quasi experiment?


  In a controlled setting, but doesn't manipulate iv it simply exists

  - DV may be naturally occurring it devided by experimenter

  E.g age/gender
• What are the strengths of a lab experiment


  - extrenous variables minimised

  - can be easily replicated ( as control reduces change of new EVs)

  -well controlled (iv and dv can be tightly controlled and meaured)= results have high validity
• whats the strengths of field experiments?


  - particpants usually unware being studied (minimises demand characteristics )= high external validity

  - more natural environment increased ecological validity (people act more authentic = high mudane realism)
• weaknesses of natural experiments


  - random allocation of participants to each conditon is not possible ( IVs pre-existing ) (reasearcher less sure whether iv links to dv)

  - natural occurring events may be rare (decreases opportunity of gathering research)

  - cant replicate experiment and try get similar results (no control over IV and its relation to DV)
• whats the weaknesses of quasi experiments


  - cannot randomly allocate people to conditions (as characteristics are fixed risk of confounding variables )

  - particpants may be aware their being studied

  - Iv cannot be changed by researcher so we cannot be sure it is the reason behing any observable change in DV
• Strengths of natural experiments


  - allows research where iv can be manipulated that might have not been allowed to happen otherwise for ethical or practical reasons (e.g study of romanian orphans )

  -enables psychologist to study real world problems and issues (e.g effect of natural diaster on stress levels )

  - great external validity
• Strengths of quasi experiments


  - allows comparison between types of people ( as IV is difference between people )

  - carried out under controled conditons so varibales can be controlled)(same strengths as lab )
• weaknesses of lab experimensts

  - artificial situation - lacks generalisability

  - participants are aware that their in an experiment (demand characteristics )

  - tasks particpants are asked to carry out may not reflect how they would in real life ( low mudane realism) .