Research methods

• What does experimental design describe?


  The way participants are allocated to experimental groups of an investigation
• What are the three possible experimental designs?


  • Independent Measures/Groups
  • Repeated Measures/Groups
  • Matched Pairs
• What effect does hunger have on the perception of food according to previous research?


  People rate pictures of food as brighter if they are hungry
• How could you study the effect of hunger on food perception before lunch?


  Ask participants to rate pictures of food before lunch
• How could you study the effect of hunger on food perception after lunch?


  Ask one group to rate food just before lunch and another group after lunch
• What is a characteristic of independent measures/groups design?


  Data from each group is independent of each other
• What is an advantage of using independent measures/groups design?


  It eliminates order effects and demand characteristics
• What is a weakness of independent measures/groups design?


  There may be individual differences among participants which could be a confounding variable
• How do researchers minimize individual differences in independent measures/groups design?


  By having a large sample and randomly allocating participants to conditions
• What is a characteristic of repeated measures/groups design?


  Each participant takes part in both conditions of the experiment
• What is an advantage of repeated measures/groups design?


  It minimizes individual differences as the same people are in each group
• What is a weakness of repeated measures/groups design?


  Order effects may occur due to practice or fatigue
• How can researchers address order effects in repeated measures/groups design?


  By counter-balancing the order in which participants do the task
• What are demand characteristics in repeated measures/groups design?


  Participants may guess the aim of the experiment due to their second attempt
• What is matched pairs design?


  Participants are carefully matched on a number of variables
• What is an advantage of matched pairs design?


  It allows control of individual differences and order effects
• What is a weakness of matched pairs design?


  Matching is extremely difficult and may not eliminate individual differences
• How does matched pairs design differ from independent groups design?


  Matched pairs design controls for individual differences while independent groups do not
• What are the factors affecting control of variables in research?


  Extraneous variables, confounding variables, demand characteristics, and investigator effects
• What is an extraneous variable?


  An unwanted variable, other than the IV, that may influence the DV
• Give an example of an extraneous variable.


  Outside temperature when timing a participant running
• What happens if an extraneous variable influences the DV?


  It becomes a confounding variable, making the research invalid
• What are confounding variables?


  Variables that influence the DV due to the effect of extraneous variables
• What are demand characteristics in research?


  Features of the research that may cause participants to change their behavior
• How can demand characteristics affect research findings?


  They can lead participants to second-guess the aim and change their behavior
• What is meant by the "screw you effect" in research?


  Participants may try to sabotage the experiment intentionally
• What are investigator effects?


  Unwanted interference by the researcher that can affect the outcome of the experiment
• How can a researcher's characteristics influence the study?


  The age, gender, ethnicity, or behavior of the researcher may influence participants
• What are the factors affecting control of variables in research?


  Extraneous variables, confounding variables, demand characteristics, investigator effects
• What is an extraneous variable?


  An unwanted variable, other than the IV, that may influence the DV
• Why is it important to control extraneous variables?


  To minimize their influence on the dependent variable
• What happens if an extraneous variable influences the dependent variable?


  It becomes a confounding variable, making the research invalid
• What are demand characteristics in research?


  Features of the research that may cause participants to change their behavior
• How can demand characteristics affect research findings?


  They can lead participants to second-guess the aim and change their behavior
• What are investigator effects?


  Unwanted interference by the researcher that can affect the outcome of the experiment
• How can a researcher's characteristics influence the study?


  Their age, gender, ethnicity, or behavior may influence participants and findings
• What are participant variables?


  Factors pertaining to participants, such as age, intelligence, motivation, experience, and gender
• What are situational variables?


  Factors pertaining to the research situation, such as time of day, temperature, and noise
• What are the methods to control variables in research?


  • Randomisation
  • Standardisation
  • Control of variables
• What is randomisation in research?


  Using chance to reduce the researcher's influence on the design of the investigation