Welcome to the Tampa Bay Chapter of QAI

President's Message

Updated November, 2013

Hello TBQAA Members and Visitors!

Thanks for visiting the TBQAA website. In the last 'President's Letter' I had shared some great information from QAI's course Essentials of Software Testing on Test Case and Code Heuristics. This month I'd like to provide some related information on Positive Contagion within defects. The Merriam-Webster dictionary defines 'contagion' as 'corrupting influence or contact' or 'rapid communication of an influence'. I cannot emphasize enough the benefit of having your testing team understand this concept. Doing so will significantly increase the number of defects discovered simply because testers will better realize that, the majority of time, there is in fact a common pattern and relationship among defects.

In other words:
  • Positive contagion within defects simply implies that if one defect is found in a module/unit, there are likely other defects in the same module/unit because:
  • Programmers and designers have bad days - one defect may indicate the presence of other defects because that part of the system was implemented on the same day
  • Programmers and designers often make the same mistakes (e.g., if s/he does not understand pointers then there will be many pointer-related defects in the same piece of code)
  • Design defects tend to be amplified into many code defects: the presence of a code defect may indicate the presence of other defects because of the same design problem
  • Because of bad fixes (on average approximately one in six fixes introduce new defects); modules that had many defects fixed in them will likely have new defects introduced in them
I hope this helps. Please let me know if you have any questions or thoughts you'd like to add.

Happy testing!same

Bob Crews
TBQAA Chapter

Email: bcrews@checkpointech.com

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   President:         Bob Crews
   Vice President:  Pam Ripplinger
   Treasurer:         Paul Zancara Jr.
   Secretary:         Margaret Callaghy
   Director of Programs: Brian Odgers