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Vrije Universiteit Amsterdam
Hypothesis: a formal statement about a phenomenon
● Null hypothesis H0
: no real trends or patterns in the
experiment setting (aka ~Q)
● Alternative hypothesis Ha: there are real trends or
patterns in the experiment setting (aka Q)
Vrije Universiteit Amsterdam
● We aim at verifying the null hypothesis (~Q)○ we test the null hypothesis H
0
We can reject the null hypothesis → we can draw conclusions
This comes from Popper (1959): any statement in a scientific
field is true until anybody can contradict it
● Aiming at verifying Q is WRONG○ Provides no insight on the conjecture
Vrije Universiteit Amsterdam
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"P-value in statistical significance testing" by User:Repapetilto @ Wikipedia & User:Chen-Pan Liao @ Wikipedia - https://en.wikipedia.org/wiki/File:P_value.png. Licensed under CC BY-SA 3.0 via Wikimedia Commons
Vrije Universiteit Amsterdam
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● Analysis and Interpretation: Chapter 10
Experimentation in SE, Wohlin et al. (Blackboard)
● Hypothesis Testing: Chapter 10, Section 3
Experimentation in SE, Wohlin et al. (Blackboard)
● "It's the effect size, stupid" (Coe, R.)
● Plenty of online resources\tutorials
Vrije Universiteit Amsterdam
● Coin toss example and other content from Empirical
Methods in Software Engineering, Marco Torchiano,
Politecnico di Torino - http://softeng.polito.it/EMSE/
● Effect Size from Basics of Empirical Software Engineering,
Massimiliano Di Penta, University of Sannio, Italy
Vrije Universiteit Amsterdam
g.procaccianti@vu.nl
i.malavolta@vu.nl
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