
242 Empirical Research in Software Engineering
DOF=n−e−1, where e is the number of parameters that must be estimated
(mean [µ] and standard deviation [σ]) and n is the number of segments.
In our example, DOF = 10−2−1=7. The computed p-value is 0.0499.
Step 4: Dene signicance level.
At signicance value (0.05),
value from distribution table is 14.07. Since, the
tabulated value of
χ
2
is greater than the calculated value, the results are not
signicant. The obtained p-value is also almost equal to α=0.05.
Step 5: Derive conclusions.
The results are not signicant at 0.05signicance level. Hence, we accept thenull
hypothesis, ...