thesis - Faculty of Information and Communication Technologies ...

Chapter 5. Growth Dynamics
Percent
0 5 10 15
0 .2 .4 .6 .8 1
Cumulative Percentage
0 20 40 60 80 100 120 140 160 180
Number of Methods
Figure 5.1: Relative and Cumulative frequency distribution showing
positively skewed metrics data for the Spring Framework 2.5.3. The
right y-axis shows the cumulative percentage, while the left side shows
the relative percentage.
sion 2.5.3 of the Spring Framework. As can be observed in the figure,
approximately 20% of the classes have more than 10 methods suggesting
that relatively few classes have a large number of methods in this
system. This skewed metric distribution pattern repeats for the different
metrics that we collect in our study across all the software systems
(discussed further in Section 5.4.2).
5.1.1 Summarising with Descriptive Statistics
The sheer volume of metric data available from any object-oriented software
systems can make it difficult to understand the nature of software
systems and how they have evolved [75]. A common approach
[77, 117, 165, 182] to reducing the complexity of the analysis is to apply
some form of some simple statistical summarisation such as the
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