11 Selecting Empirical Methods for Software Engineering Research
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efficiency in file navigation correlate with the programmer’s familiarity with the programming environment?” Joe might ask,
“Do managers claims about how often they use UML correlate with the actual use of UML?”Once we have established that a relationship exists between two phenomena, it is natural to try to explain why the relationship holds by attempting to identify a cause and effect. It is
a common mistake to confuse correlation with
causality. In general it is much harder to demonstrate causality than to show that two variables are correlated. If high values of X correlate with high values of Y, it maybe because X causes Y, or because Y causes X. But it is also possible that X and Y share some common cause and neither causes the other. Or perhaps they co-evolve in complex ways so that there is no clear cause-and-effect.
Causality questions include:
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