Why We Make Mistakes; Human Error & Cognitive Biases

Dr. Andrew Brown

SQS

What are cognitive biases? Why do developers create software bugs, and why do testers fail to find them? Is the best way to improve the quality of our software to redouble our current testing efforts, or is there another approach?

Current models for software testing focus effort at the end point of the process, attempting to discover defects after they have been created.

This paper advocates an alternative approach, focusing effort where a defect starts life. It examines how thought processes lead to defects. It shows how some thought patterns, termed cognitive biases, are responsible for many of the defects we see. These biases exist in all working environments and everyone can succumb to them quite easily. This paper will explore how we can reduce our vulnerability to these biases through de-biasing techniques.

The paper was awarded the EuroSTAR Best Paper Award 2017 at the annual EuroSTAR Software Testing Conference.

Key Takeaways:

  1. Software defects start life as errors in our minds, but we never look for them there
  2. Many of these errors are predictable, caused by the biases
  3. We can reduce cognitive biases. Hence we can reduce defects

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About Me!

Dr Andrew Brown is a principal technical consultant at SQS. Recently, he has developed an independent line of research into understanding why we humans make the mistakes that lead to software defects. This research has produced a new view of defect reduction, several papers and a revamp of training and induction at SQS.

He has 25 years’ experience in the software industry. Previous roles include Head of QA at HMV, Head of QA at a financial software house and a test manager in Japan.

He holds a degree in Physics and Maths, an MBA from Warwick Business School and a doctorate from Imperial College.


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