Research methods

• Laboratory experiment


  A study carried out in a controlled setting
• Population


  The type of people we're interested in
• Opportunity sampling


  A sample that consists of people who are available
• Random sampling


  Giving each member of a population a number and using a random number generator to generate the participants
• Volunteer sampling


  Asking for volunteers via an advert or poster
• Ethical issues


  Whether the study is being conducted in the right way
• Informed consent


  Making sure the participants know what and why they're doing it before agreeing
• Deception


  False information is given or information is with-held
• Right to ask questions


  Participants can ask questions at any point during the study
• Right to withdraw


  Participants are allowed to remove their data at any point
• Protection from harm


  Participants shouldn't be affected, either physically or mentally, by the study. The defbrief ensures this
• Confidentiality


  Names and personal details of participants are not shared
• Information sheet


  A sheet given before the study telling the participants what they have to do and what the study is about
• Debrief


  A conversation between scientist and participant after the study to give all information
• Code of ethics


  From the BPS giving guidelines on what they're allowed to do
• Aim


  General statement about the purpose of the investigation
• Hypothesis


  A statement which makes a precise prediction about the outcome
• Directional hypothesis


  States which way it's going to go
• Non-directional hypothesis


  Not sure in which way the evidence will go so doesn't state it
• Dependent variable


  What we measure
• Independent variable


  What we change
• Operationalising


  Defining the variable and deciding how to measure it
• Repeated measures design


  One group of people tested under two conditions
• Practice effect


  Participants apply what they have learnt from the first condition to the second in 'repeated measures design
• Fatigue effect


  In 'repeated measures design' participants get tired
• Order effects


  The effects of 'repeated measures design' (practice and fatigue)
• Counterbalancing


  A way of overcoming order effects by swapping the order of the conditions around
• Independent groups design


  Two groups of people each with one condition
• Participant variables


  In 'independent groups design' the participants will have different characteristics
• Matched pairs design


  A pair who's characteristics are similar are paired to do one condition each
• Extraneous variables


  Things that interfere with the study from outside and effect results
• Demand characteristics


  Clues within the study that may tell the participants what the study is about
• Investigator effects


  Clues within what the experimenter does that may tell the participants what the study is abou
• Pilot study


  A small scale trial run, designed to find any problems within the method
• Reliability


  Refers to the consistency of measuring instruments
• Validity


  The extent to which the test measures what it is intended to measure
• Measures of central tendency


  Averages (mean, median and mode)
• Measures of dispersion


  Range and standard deviation
• Mode


  Value of the highest frequency
• Median


  Middle value