160 ◾ Simple Statistical Methods for Software Engineering
Review Questions
1. What is the commonly used rule for selecting number of bins in a histogram?
2. Mention three purposes for extracting histograms from data.
3. What is meant by a bimodal histogram?
4. What are the elements of a histogram signature?
5. How can you judge process capability from a process data histogram?
Exercises
1. Construct a histogram using the following customer satisfaction data and
extract the signature of customer satisfaction. Interpret the signature.
4, 5, 3; 5, 4, 5, 5, 4, 3, 4, 5, 3, 4, 5, 3, 2, 3, 2, 4, 1, 4,
1, 5, 4, 3, 4, 3, 2, 3, 2, 4, 3, 4, 3, 5, 4, 3, 5, 4, 4, 4, 4
2. Use MS Excel’s data analysis tool Histogram to construct the histogram.
Instead of allowing default bin selection, specify your own bins.
3. If the corporate goal is to get a customer satisfaction score of at least 3, what
is the risk seen in the previously mentioned histogram signature?
4. Test case rework effort data in person-hours are given as follows:
16, 16, 2, 5, 7, 8.5, 8, 9, 10, 11, 5
Draw a histogram with this limited data and try to draw inferences about
the test case development process.
5. Effort variance data in a software enhance project is shown as follows:
−10, 4, 5, −3, 8, −2, 0, 9, 5, −2, 5, 3, 5, 12
Draw an ogive of the given data.
0
2
4
6
8
10
0 2 4 6 8 10
Coupling
Figure A10.2 Frequency diagram.