Inferential testing

• What is the significance of probability in psychology research?

  It helps manage the risk of errors.
• What are the two competing hypotheses in research?

  Null hypothesis (H0) and alternative hypothesis (H1)
• What does the null hypothesis suggest?

  There is no causal relationship between variables.
• What does the alternative hypothesis suggest?

  There is a causal relationship between variables.
• How is the independent variable manipulated in an experiment?

  By creating separate conditions for testing.
• What is the dependent variable in the example given?

  The number of words recalled from a list.
• What was the directional hypothesis in the example study?

  Recall will be better in the green light condition.
• What does counterbalancing aim to control for in experiments?

  Order effects in participant responses.
• What was the average recall in the green light condition?

  13 words
• What was the average recall in the blue light condition?

  12.5 words
• Why might the data not be strong enough to accept the alternate hypothesis?

  The difference could be due to chance.
• What is the accepted probability level for psychologists to accept an alternate hypothesis?

  0.05 or 5%
• What does a probability of 0.05 mean?

  There is a 1 in 20 chance of error.
• What does a number line represent in terms of probability?

  Zero means impossible, one means certain.
• What is the probability of flipping a fair coin and getting heads?

  50% or 0.5
• What is the probability of rolling a six on a six-sided die?

  Approximately 17% or 0.17
• Why is it important to consider unknown factors in scientific assumptions?

  To avoid absolute certainty in conclusions.
• What is a type 1 error?

  Accepting a false alternate hypothesis.
• What is a type 2 error?

  Rejecting a true alternate hypothesis.
• How can researchers reduce the likelihood of a type 1 error?

  By using a stronger level of significance.
• How can researchers reduce the likelihood of a type 2 error?

  By using a less strict level of significance.
• How do type 1 and type 2 errors relate to jury decisions?

  • Type 1 error: Jury wrongly convicts an innocent person.
  • Type 2 error: Jury wrongly acquits a guilty person.
• What are the key concepts in probability and significance in psychology?

  • Null hypothesis (H0) and alternate hypothesis (H1)
  • Type 1 and type 2 errors
  • Level of significance (p < 0.05)
  • Importance of probability in research decisions