Research Methods

• Define independent variable

  What the researcher manipulates in the experiment
• Define dependent variable

  What the researcher measures in the experiment
• Define the experimental hypothesis

  A prediction about the expected outcome of the experiment
• Define the null hypothesis

  The hypothesis the researcher is trying to disprove. States the results won't be significant
• Define operationalisation

  Describing the variables in terms of how they will be precisely manipulated and measured
• Define directional hypothesis

  Hypothesis specifically states the direction of the results
• Define non-directional hypothesis

  Hypothesis doesn't specify the expected direction of the results
• Explain the key features of a lab experiment

  -Tightly controlled, artificial environment

  -Researcher deliberately manipulates independent variable

  -Attempt to control extraneous variables

  -Standardised procedures
• Explain the key features of a field experiment

  -Natural, 'real world' environment

  -Researcher deliberately manipulates the independent variable

  -Minimal control of extraneous variables
• Explain the key features of a natural experiment

  -Any setting

  -The independent variable is not manipulated

  -Little control over extraneous variables

  -The independent variable is an event or experience
• Explain the key features of a quasi experiment

  -Any setting

  -The independent variable is not manipulated

  -Little control over extraneous variables

  -The independent variable are existing characteristics
• Define standardised procedures

  Controlled conditions allowing for replication
• Define ecological validity

  The extent to which an experimental setting represents real life situations
• Define demand characteristics

  Participants behaviour in the experimental setting may be unnatural
• Define validity

  The extent to which an experiment is accurate in what it claims to measure
• Define mundane realism


  The extent to which the tasks are representative of tasks completed in every day life
• Define reliability

  The extent to which an experiment can be repeated to check the consistency of results
• Define internal validity

  The extent to which there is confidence in the independent variable causing the effect on the dependent variable, establishing 'cause and effect'
• Define extraneous variable

  A variable that may affect the dependent variable if it is not controlled. They make it difficult to detect if the independent variable has had an effect
• Define confounding variable

  A type of extraneous variable that systematically changes alongside the independent variable so acts as another independent variable and could cause the change in the dependent variable
• Define situational variable

  Features of the environment that could affect the participant's behaviour
• Define participant variable

  Individual differences between participants and the ways each participant varies from the other
• Define investigator effects

  Any unwanted influence of the researcher's behaviour on the participants data/outcome
• Explain the repeated measures experimental design

  -Same people in each condition of the independent variable

  -All participants do both conditions

  -Participant variables are controlled

  -Demand characteristics may occur

  -Order effects may occur
• Explain the independent groups experimental design

  -Different people in each condition

  -Their performance is compared

  -Half do condition A, half do condition B

  -Less chance of order effects

  -Less chance of demand characteristics

  -Participant variables are uncontrolled
• Explain the matched pairs experimental design

  -Different people in each condition

  -Participants in one condition are matched with participants in the other condition by key variables such as gender

  -Less chance of order effects

  -Less chance of demand characteristics

  -Difficult design to achieve
• Define target population

  The group of people who the researchers want to generalise their results to
• Define sample

  Small number of people taken from the target population who participate in the investigation
• Name and describe the 5 types of sampling

  Random -> Every participant has an equal chance of being selected with no bias

  Opportunity -> Approaching and inviting those who are available

  Volunteer -> Advertising the study and individuals respond if they want to participate

  Systematic -> Sampling frame and a system to select every nth person

  Stratified -> Identifying strata and calculating proportions and is used to obtain a selected number of participants
• Give an advantage and disadvantage of random sampling

  + Representative of target population

  -More time consuming and inconvenient
• Give an advantage and disadvantage of opportunity sampling

  + More convenient

  -Unlikely to be representative
• Give an advantage and disadvantage of volunteer sampling

  + More convenient

  -Unlikely to be representative
• Give an advantage and disadvantage of systematic sampling

  + Representative of target population

  -Still possible to be unrepresentative
• Give an advantage and disadvantage of stratified sampling

  + Very representative

  -Very time consuming and inconvenient
• Describe a correlation coefficient

  A more accurate way to indicate the strength of a correlation. It is a statistical value of a number between -1 and +1
• Define quantitative data

  Numerical data consisting of participants scores or numbers of some sort
• Define qualitative data

  Descriptive data expressed in words in the form of written thoughts, feelings and opinions
• Give advantages and disadvantages of quantitative data

  + Objective so free from bias

  + Mathematically analysed

  -Fails to consider participants feelings and emotions

  -Lacks insight into the reasons behind behaviour
• Give advantages and disadvantages of qualitative data


  + More data

  + Gives meaningful insight for high external validity

  -Difficult to analyse so comparisons are difficult

  -Conclusions are based on subjective interpretations
• Define primary data

  Data collected by researcher first hand and is gathered from the participants directly