probability and significance

• observed value

  single number calculated by a stat test from scores found in the study
• critical value

  value from a table for the appropriate statistical test to which an observed value is compared
• what is the probability set in most psychological research

  p$\le$0.05
• what does p$\le$0.05 mean?


  5% probability that a pattern could simply have risen by chance
• if a psychologist wanted to be more sure, what significance level at probability could they set it as?

  1% (p$\le$0.01) or 0.1% (p$\le$0.001)