Choosing an Appropriate Statistical Test

• What must a psychologist use to decide which hypothesis to accept?

  A statistical test
• Why do psychologists choose different statistical tests?

  To match the study's specific requirements
• What are the three steps psychologists follow when choosing statistical tests?

  1. Determine if looking for a difference or correlation
  2. Identify the level of measurement used
  3. Decide if the design is unrelated or related
• What is the first step in choosing a statistical test?

  Identify if looking for a difference or correlation
• What indicates a test of difference in a hypothesis?

  Words like difference, increase, decrease
• What does the term 'nominal' refer to in measurement levels?

  Categories with frequency counted
• What does 'ordinal' measurement involve?

  Ranked data without a universal scale
• What is 'interval' measurement?

  Measurements using a universally accepted scale
• What type of data is associated with repeated measures design?

  Related data
• What type of design is independent groups design?

  Unrelated data
• What is the significance of the correlation step in the design choice?

  It does not matter for correlation investigations
• What is the Chi-square test used for?

  • To find a difference or association
  • Requires nominal data
• What are parametric tests?

  • Most accurate statistical tests
  • Used with interval/ratio data
• What mnemonic can help remember the statistical tests table?

  Carrots Should Come Mashed With Swedes
• What does the rule of R indicate about certain statistical tests?

  Calculated value must be ≥ critical value
• What is required for tests where the calculated value must be ≤ critical value?

  All tests except those with 'R'
• What are the types of statistical tests based on design and data type?

  • Unrelated design: Chi-Square, Mann-Whitney, Unrelated t-test
  • Related design: Sign Test, Wilcoxon, Related t-test
  • Correlation: Spearman’s rho, Pearson’s r
• What does a one-tailed test indicate?

  A directional hypothesis was used
• What does 'N' represent in statistical tests?

  Number of participants or pairs of data
• What does 'Df' stand for in statistical tests?

  Degrees of freedom
• Are students required to calculate values for certain tests?

  No, except for the sign test
• What should students practice regarding the sign test?

  Calculating the value
• What should students do before interpreting results from studies?

  • Consult the critical values tables
  • Read the interpretation after checking the table