Part 1

• Aim


  General statement of the purpose of an investigation
• Hypothesis


  A testable statement that states the relationship between the variables to be investigated
• Importance of operationalisation


  A hypothesis can only be tested if the variables being studied can be measured accurately
• Null hypothesis


  A statement which predicts no difference or relationship in the results
• Experimental/alternative hypothesis


  A statement that predicts a difference or a relationship in results
• Directional hypothesis (one-tailed)


  Specifies the direction of results and is done when previous research has been done
• Non-directional hypothesis(two tailed)


  States there will be a difference between 2 groups in an operationalised way without stating the direction of results

  Is used when there is no previous research or previous research has found contradictory results
• Extraneous variable


  A variable that varies systematically other than the IV that might have an effect on the DV (e.g. weather or noise) if it is not controlled. Nuisance variables that do not vary systematically with the IV
• Confounding variable


  A kind of EV that varies systematically with the IV
• Pilot study


  Small scale trial run of a study which takes place before the study
• Aims of a pilot study

  Check procedures, materials and measuring scales work, and allow the researcher to make changes if needed
• Use of pilot studies (questionnaires + interviews)

  Try out questions in advance, re-word and remove confusing ones
• use of pilot studies (observation studies)

  check behavioural categories + coding systems
• Significance of pilot studies


  Improves quality of research and avoid unnecessary work, save time and money
• What is an Independent Variable?


  Something that is manipulated by the researcher or naturally changes
• What is a Dependent Variable?


  Variable that is measured by the researcher
• What does operationalise mean?


  To be precise and clear about what is being measured. It must be testable and repeatable
• Examples of operationalisation?

  • Number of words accurately recalled
  • Reaction times in seconds
  • Number of faces accurately recognised
• Experimental Design


  Refers to the way in which we put our PPs into groups in the experiments
• What is Independent Groups?

  1. PPs are randomly allocated to one condition of the IV
  2. One group undergoes one condition and other group undergoes the other condition
• Strengths of Independent Groups

  • No order effects as the people only take part in one condition
  • Same materials can be used for the other condition so time and money can be saved
  • PPs cannot work out the aim of the study as they only take part in one condition reducing demand characteristics
• Weaknesses of Independent Groups

  • Participant variables (individual differences) such as age and gender may affect the results
  • More PPs are needed as different people take part in different conditions
• What is Repeated Measures?

  PPs take part in both conditions of the IV
• Strengths of Repeated Measures

  1. Half the number of people needed as they take part in both conditions
  2. The PPs are the same so there is no individual differences
• Weaknesses of Repeated Measures

  • Order effects may happen such as boredom and fatigue as PPs have taken part in both conditions
  • PPs may guess the aim of the study so demand characteristics may occur affecting the results
• How can you limit order effects in a repeated measures design?

  By counterbalancing
• What is counterbalancing?


  An attempt to control order effects in a repeated measures design: half the participants experience the conditions in one order and the other half in the opposite order
• How is counterbalancing done?

  • In one group half the PPs take part in Condition 1 and then Condition 2
  • The other half then take part in Condition 2 and then Condition 1
  • Counterbalancing attempts to balance out the order effects
• What is Matched Pairs?

  1. PPs are matched based on similarities or key characteristics e.g gender or IQ
  2. One of the pair is then randomly allocated to Condition A and the other to Condition B and undertake different conditions of the IV
• Strengths of Matched Pairs

  • Reduces the number of characteristics thought to influence the DV making matching easier and saves time
  • Conduct a pilot study to identify the key characteristics relevant to the study
• Weaknesses of Matched Pairs

  • Time consuming to test PPs and match them based on important characteristics
  • Difficult to reduce all participants variables that may affect the DV
• What is a population?

  A group of people who are the focus of the researcher's interest from which a small sample is drawn
• What is a sample?


  A group of people who take part in a research investigation
• What is bias in terms of sampling?


  When certain groups are under or over represented within the sample selected
• What is Generalisation?


  The extent to which findings from a particular investigation can be applied to the population
• What is a Random Sample?


  Everyone has an equal opportunity of being picked

  Use a random number generator
• Strengths of Random Sampling

  1. Unbiased
  2. Representative
• Weakness of Random Sampling

  1. Impractical as it is hard to include everyone in the population
  2. Time consuming
• What is Systematic Sampling?

  Selecting PPs from a target population by selecting them at pre set intervals

  e.g selecting every 50th person in a list
• Strengths of Systematic Sampling

  1. Unbiased so no researcher bias
  2. Representative