Statistical Significance

Statistical Significance

1. Significance

   • Means that the data has been analysed and the probability that the results were obtained by chance or sampling error are at minimum

2. The goal of psychological research is to reject the null hypothesis.

   • Null Hypothesis
     • says that the data is random, or that it resulted from sampling error
   • If the probability taken from the inferential test is less than 5% can be rejected
     • Some might reach <1% for risky studies as in drugs and psychological interventions
     • The 5% means that if the null hypothesis is true, the specific data we have gathered is only available 5% of the time which is extreme, so we can reject the null hypothesis

3. Inferential Tests

   • Non-Parametric tests
     • Mann-Whitney U test
     • Chi-Square Test
     • are more appropriate for any data not meeting those requirements.
   • Parametric tests
     • Independent samples t-test
     • Paired samples t-test
     • are appropriate for data sets that both resemble the normal distribution