Cognitive bias is said to be the pattern of irrationality in judgment which causes humans to make errors and misjudgments. A human brain is a universe in itself, with so many aspects yet to be explored and just how its processes fascinate us in so many ways. Our brains are also influenced by different types of biases. In this article, we will specifically talk about biases that impact testers’ brains and how they can influence their decisions regarding where to look for bugs, which areas to test intensively, etc. 

Types of Cognitive Biases

1. Confirmation Bias

Confirmation bias is the tendency of individuals to focus or seek for pieces of information that validate their long-held beliefs. This bias restricts individuals to their own perspective and from exploring other avenues and options that might be more beneficial for them. In short, it limits their rational capabilities. Due to this bias, a tester may not test a code comprehensively if he has extremely positive views about the developer who wrote the code.

2. In-attentional Blindness

This is a term used to imply a failure to grasp obvious details but the one looking for them isn’t paying enough attention. In the world of testing, it could mean that testers and developers focus all their attention on a newly added feature or a new update and fail to spot defects in other areas of the software.

3. The Optimism Bias and Negativity Bias

Both of these biases are opposites to one another and depend on the personality and nature of the person. A person is said to have a negativity bias if he expects a negative outcome for every endeavor whereas an optimism bias is in play when a person is too optimistic about the results. In software testing, negativity bias may hinder a tester from putting extra effort into finding bugs and making software as perfect as possible. Whereas, a person influenced by optimism bias may think that software is free of defects if he doesn’t find any bugs within an hour of testing. This might affect his ability to find defects in other areas of software.

4. Congruence Bias

In one of my articles, I wrote that one of the essentials to be a tester is to always be curious. By curious, I mean the willingness to not only test for an expected behavior but to also play with the application using various defect tracking software and try different new ways to see if and how the software makes mistakes. Congruence bias affects this ability of the tester and satisfies him if the software meets his criteria in the mind without considering that those criteria may not be enough to make an informed decision.

5. Bandwagon Effect

This term refers to the influence opinions have on a human brain. In software testing, a tester is sometimes so much influenced by the opinions of his peers or team members that he may not give proper time and attention to the software his team thinks is bug-free.

Conclusion

The solution to all these biases affecting testers’ performances is proper training programs that educate them about these biases and how they can be dealt with. Researchers believe that gamifying is an effective technique to train testers. This technique can be implemented by a good defect tracking software. Minimizing these biases would limit the mistakes in judgments testers make.