Control of Variables

• What does an aim identify in an investigation?

  The purpose of the investigation
• What is an independent variable (IV)?

  The variable the experimenter manipulates
• What do levels of IV/DV refer to?

  How many different conditions there are
• What is operationalisation in research?

  Making variables measurable as stated in aims
• When do we use a directional hypothesis?

  When previous research suggests a direction
• What is a dependent variable (DV)?

  The variable observed or measured
• What should only influence the DV in an experiment?

  The independent variable (IV)
• What is an extraneous variable?

  An unwanted variable that may affect the DV
• What is a confounding variable?

  An extraneous variable that systematically varies with the IV
• What are the implications of controlling extraneous variables in an experiment?

  • Ensures validity of results
  • Reduces bias in measurements
  • Maintains consistency across conditions
• What is one extraneous variable that could affect study results?

  Consumption of caffeine or alcohol
• What is an experiment?

  A method to test hypotheses under controlled conditions
• What are the three types of experimental designs?

  Independent groups, repeated measures, matched pairs
• What are order effects in experiments?

  Boredom or fatigue from repeated conditions
• What are demand characteristics?

  Participants change behavior based on perceived intentions
• What are participant variables?

  Individual differences like IQ or age
• What does economic refer to in experimental design?

  Costs associated with conducting the experiment
• What does time-consuming refer to in experiments?

  The duration required to conduct the study
• What is an independent groups design?

  Participants are allocated to different conditions
• What are the strengths of independent groups design?

  No order effects from repeated conditions
• What are the weaknesses of independent groups design?

  Participant variables may affect results
• What are the strengths and weaknesses of repeated measures design?

  Strengths:

  • Controls participant variables
  • Fewer participants needed

  
  

  Weaknesses:

  • Order effects may bias results
  • Time-consuming for participants
• What are the strengths and weaknesses of matched pairs design?

  Strengths:

  • Controls participant variables
  • Reduces order effects

  
  

  Weaknesses:

  • Time-consuming to match participants
  • Not always possible to find matches
• What are the types of experimental designs?

  1. Independent groups
  2. Repeated measures
  3. Matched pairs
  4. Laboratory
  5. Field
  6. Natural
  7. Quasi
• What type of design is an independent group measures design?

  Participants are allocated to different conditions
• How are participants allocated in an independent groups design?

  Based on the levels of the independent variable
• What is measured in each condition of an independent groups design?

  The dependent variable
• What is a strength of independent groups design regarding order effects?

  No order effects occur
• Why are demand characteristics less likely in independent groups design?

  Participants only experience one condition
• What is a potential issue with participant variables in independent groups design?

  Individual differences may influence the dependent variable
• What is a disadvantage of independent groups design in terms of data collection?

  It is time-consuming due to needing more participants
• What type of design is a repeated measures design?

  Same participants take part in all conditions
• What is a potential issue with repeated measures design regarding order effects?

  Participants may become fatigued or bored
• What is a strength of repeated measures design regarding participant variables?

  No participant variables exist as the same participants are used
• Why is repeated measures design less time-consuming?

  Fewer participants are needed for data collection
• What is a disadvantage of matched pairs design regarding matching participants?

  Matching may not be perfect
• What is a strength of matched pairs design regarding order effects?

  No order effects occur as participants do different conditions
• What is a disadvantage of matched pairs design regarding time and cost?

  It is time-consuming and may be expensive
• What is a limitation of a repeated measures design?

  Order effects may reduce the validity of results
• What is a strength of a repeated measures design?

  No participant variables increase the validity