Statistical terms

• Why do we use statistical tests?

  To tell us if results are significant or due to chance, they determine whether the null hypothesis can be accepted or rejected
• What is the p-value?

  there is a p% probability that the difference/ correlation is due to chance.
• What does a P-value less than 0.05 mean?

  The difference/ correlation IS significant. It is less likely that the results are due to chance and that they are caused by another real factor.
• What does a P-value more than 0.05 mean?

  There is no statistical significance, the higher the p-value is, the more likely that the results are due to chance, they are not caused by other factors.
• Do we accept or reject the null hypothesis if the result is significant?


  Reject the null hypothesis
• What is the null hypothesis?

  The null hypothesis is a statement that assumes there is no significant relationship or correlation between variables being studied.
• When is a T-test used?

  To compare the means of two unrelated sets of data, of which the data has been measured.
• What does causes a significant result in a T-test?

  The observed value must be less than the critical value of 0.05
• When is a correlation coefficient (Pearson's/ Spearman's) test?

  Used to test for a relationship between two variables, it is a value between -1 and +1.
• What does a value of zero indicate in a correlation coefficient test?

  There is no correlational relationship between the varibles
• What does a value between 0 and +1 indicate in a correlation coefficient test?

  A positive correlational relationship between the variables being studied.
• What does a value between -1 and 0 indicate in a correlation coefficient test?

  A negative correlational relationship between the variables being studied.
• When is a chi-squared test used?

  Used when looking at data that has been counted (not measured), and seeing if the difference in expected and observed results are significant.