Statistical testing - Sign Test

• what is statistical testing?

  • a way of determining whether hypotheses should be accepted or rejected
  • we can find out if the relationship between the variables are meaningful: significant or chance related
• why are statistical tests used?

  To determine if there is a significant difference or relationship between variables. Because you cannot only use the mean difference.
• what is the Sign Test?

  a statistical test that can determine whether the difference we have found is significant
• How do you use the Sign Test?

  • need to be looking for a difference between variables
  • used a repeated measures design
  • data needs top be organised into categories, known as nominal data
• what is nominal data?

  data that is categorised. e.g. yes/no, male/female
• what is the excepted probability in psychology?

  0.05 or 5% -> this is used on tables given in the exam. However it may state otherwise in the exam what probability to use.
• why is there an excepted probability?

  it allows the researcher to have a level to measure if the findings are significant so they can either accept or reject the Null Hypothesis or Alternate Hypothesis
• what is a null hypothesis?

  a hypothesis that states that there will be no difference/association between conditions
• what is an alternate hypothesis?

  a hypothesis that states there will be a difference/association between the conditions
• what is a critical value?

  a value that decides whether the results are significant or not
• what happens to the critical value?

  it gets compared to the calculated value
• what is a calculated value?

  the value the researcher has been left with after doing the statistical test
• what information do you need to use a Critical Value Table?

  • the probability (0.05 most likely)
  • the number of participants in the investigation
  • whether the hypothesis is directional or non-directional (one tailed or two tailed
• what hypothesis is one tailed?

  directional hypothesis (because it goes one way)
• what hypothesis is two tailed?

  a non-directional hypothesis (because it can go many ways)