Statistical tests are conducted to determine whether the changes or differences between two result numbers are statistically significant. The term "significant" does not imply a judgment about the absolute magnitude or educational relevance of changes in student performance. Rather, it is used to indicate that the observed changes are not likely to be associated with sampling and measurement error.
The probability that the association between the factor and the outcome is due to chance is less than a specified level (by convention, p 0.05).
Significance tests are performed to see if the null hypothesis can be rejected at a certain level of significance.