cognitive research methods

• what are the two types of experiment

  lab and field
• what happens in a lab experiment, where

  - conducted in a high controlled, artificial environment

  - independent variable manipulated and its effect on the dependent variable is measured
• what happens in a field experiment, where

  - conducted in a more natural setting where the behaviour would normally be seen
• what is the independent variable in an experiment


  the variable the researcher will change or manipulate
• what is the dependent variable

  the variable that the researcher will measure/record
• what is a hypothesis

  a prediction of what is likely to happen in the investigation based on previous knowledge, research, or theories
• what is operationalisation


  defining variables in a clear and objective way that can easily be identified and measured
• what is a directional/one tailed hypothesis

  saying the direction (outcome) of an experiment because we know what will happen, with details
• what is a non-directional/two tailed hypothesis

  saying there will be a difference/relationship on the results found but doesn't state which direction the difference/relationship will take
• what is a null hypothesis

  an operationalised statement predicting that there will be no difference/relationship etc. in results
• what are extraneous variables

  any variable other than the independent variable that may have an effect on the data measured
• what two types of extraneous variables are there

  1 - situational

  2 - participant
• examples of situational variables

  lighting, noise, temperature, other people, disturbance, time of day
• examples of participant variables

  level of motivation, personality, intelligence, experience, age, skills
• what are demand characteristics, what are they created by

  a change of behaviour in participants made as participants know they are being experimented on
• what are experimenter effects

  when the way an experimenter behaves (through actions, words, or presence) may influence the outcome of an experiment
• what is a confounding variable

  a variable that has affected the findings of a study directly, so much that the experiment is no longer measuring what was intended
• what are the three types of experimental research designs

  repeated measures, independent measures, matched pairs
• what happens in repeated measures experiment design

  the same participants take part in all conditions
• advantages of repeated measures experiment design (2)

  - participant variables eg individual differences are reduced

  - fewer people needed as they take part in all conditions
• disadvantages of repeated measures experiment design (2)

  - performance in second task could be better than first as participants know what to do

  - participants may be tired so perform worse
• what happens in independent measures design

  each participant only takes part in one condition, and a different set take part in the other
• advantages of independent measures design (2)

  - avoids order effects eg practice

  - participants will perform their best and won't be fatigued from doing another condition
• disadvantages of independent measures design (2)

  - more people are needed than with repeated measures

  - individual differences between participants may affect results
• what happens in matched pairs experimental design

  participants are matched with a pair in terms of key variables eg age, one participant from each pair goes in one group, the other into the other group
• advantages of matched pairs design (2)

  - reduces participant variables

  - avoids order effects
• disadvantages of matched pairs design (3)

  - if one participant drops out the other partner cant be used so you are two people down so less data

  - very time consuming to find closely matched pairs

  - impossible to match people exactly
• what is standardisation


  making an experiment the same for all participants
• why is standardisation important

  improves the reliability of the experiment
• what is a single blind experiment

  where the participant doesn't know they are part of an experiment or have been deceived of the true nature of the study
• why are single blind experiments done

  to control demand characteristics so their performance isnt affected
• what is a double blind experiment

  when independent researchers are not told the aim of the study and the participant also doesnt
• why are double blind experiments used

  to eliminate experimenter effects
• what is counterbalancing


  alternating the order of the condition in a repeated measures design so that the order effects are minimised
• what does reliability refer to

  the consistency in a study
• when is something viewed as reliable

  when we get the same results repeatedly
• what three ways are there to test and improve reliability depending on the research method used

  1 - test retest reliability

  2 - split half reliability

  3 - inter-rater reliability
• how does test retest reliability work

  - if the measure depends upon interpretation of behaviour, we can compare the results from two or more tests in different times/groups

  - if the results are the same after retesting then it is said to be consistent

  - then tests must be reformed to ensure consistency
• how does split-half reliability work

  - comparing the results of one half of a test with results from the other half - can be split in many ways eg odd and even numbered participants

  - if the two halves provide similar results then there is internal reliability

  - then test must be reformed to ensure consistency
• how does inter rater reliability work

  - when more than one researcher is used to collect data

  - if there is a high agreement between the researchers then the measure is consistent

  - to deal with this, strict criteria must be provided to enable consistent observation