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Fallacies in QA: Enhancing Critical Thinking and Decision Making

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In the dynamic world of software quality assurance (QA), it is crucial to navigate through the potential pitfalls of fallacious reasoning. Fallacies can lead to flawed decision-making, misguided conclusions, and compromised testing processes. This blog aims to shed light on various fallacies commonly encountered in software QA, presenting real-world case studies and practical strategies to avoid them. By recognizing and addressing these fallacies, QA professionals can enhance critical thinking, foster evidence-based approaches, and elevate the overall quality of their testing efforts.

Here are different fallacies related to software QA, along with case studies and strategies to avoid them:


① False Positive Fallacy

This fallacy occurs when a test falsely indicates a defect or failure that does not actually exist.

Case Study: In a software QA scenario, imagine a team is conducting security testing on a web application. One of the automated tests consistently detects a critical security vulnerability. However, upon manual inspection, the QA team realizes that the test was misconfigured, leading to a false positive result.

Avoidance Strategy:

  • To avoid false positives, it is crucial to regularly review and update the test cases and configurations.

  • Perform manual validation when automated tests fail and involve multiple team members in the verification process.

  • Additionally, invest in robust test design techniques, such as equivalence partitioning and boundary value analysis, to minimize false positives.


② Confirmation Bias Fallacy

This fallacy occurs when QA professionals interpret test results or observations in a way that confirms their existing beliefs or expectations, disregarding contradictory evidence.

Case Study: A QA team is testing a new feature in a software application. They have preconceived notions that the feature is likely to have performance issues. During testing, they primarily focus on scenarios that support their belief, overlooking cases where the feature performs well.

Avoidance Strategy:

  • Foster an open and unbiased mindset in QA.
  • Encourage testers to actively seek out contradictory evidence and conduct a comprehensive range of tests to ensure balanced evaluations.
  • Implement peer reviews and cross-team collaborations to minimize individual biases.
  • Additionally, maintain clear documentation of test objectives and success criteria to reduce the influence of confirmation bias.

③ Appeal to Authority Fallacy

This fallacy occurs when a decision or conclusion in QA is based solely on the opinion or authority of an individual or group, without sufficient evidence.

Case Study: A QA team receives a report from a well-known industry expert claiming that a specific testing technique is ineffective. Without conducting their own research or analysis, the team completely disregards the technique, potentially missing out on valuable insights and approaches.

Avoidance Strategy:

  • Avoid relying solely on authority or opinions.
  • Encourage critical thinking and promote an evidence-based approach in QA.
  • Encourage the team to conduct their own research, gather data, and analyze results before making any conclusions.
  • Foster a culture of continuous learning and experimentation to explore new techniques and challenge existing practices.


④ False Dilemma Fallacy

This fallacy occurs when only two extreme options are presented as the only possible choices, disregarding other potential alternatives.

Case Study: In software QA, a false dilemma can arise when a project manager insists on releasing a software product with critical defects because they believe delaying the release is the only other option, ignoring the possibility of prioritizing and addressing the most severe issues.

Avoidance Strategy:

  • Promote effective communication and collaboration between stakeholders, including developers, testers, and project managers.
  • Encourage discussions to explore alternative options and prioritize bug fixes based on risk and impact.
  • Implement risk-based testing approaches to identify and address critical defects early in the development lifecycle.


⑤ Anecdotal Evidence Fallacy

This fallacy occurs when a conclusion or decision in QA is based on isolated or personal experiences, rather than relying on empirical data or comprehensive analysis.

Case Study: A QA tester encounters a minor bug during testing and concludes that the entire system is unreliable based on that single experience, without considering the overall performance of the software.

Avoidance Strategy:

  • Emphasize the importance of data-driven decision-making in QA.
  • Encourage testers to gather empirical evidence through comprehensive testing, collecting and analyzing metrics, and conducting structured experiments.
  • Implement robust defect tracking and analysis processes to identify patterns and trends, ensuring that conclusions are based on a wide range of evidence.

⑥ Bandwagon Fallacy

This fallacy occurs when a belief or decision in QA is justified simply because many other people or organizations hold the same belief or have made a similar decision.

Case Study: A QA team decides to adopt a specific test automation tool solely because it is popular in the industry, without thoroughly evaluating its suitability for their specific requirements.

Avoidance Strategy:

  • Encourage a thorough evaluation process for selecting QA tools and technologies.
  • Define clear evaluation criteria based on the team's specific needs, such as ease of use, scalability, integration capabilities, and community support.
  • Conduct hands-on evaluations and proof-of-concept projects to assess the tool's fit for the organization.
  • Seek feedback from other teams and industry experts, but make the final decision based on the team's own evaluation.

⑦ Appeal to Tradition Fallacy:

This fallacy occurs when a particular QA practice or approach is favored solely because it has been followed for a long time, without considering its effectiveness or relevance in the current context.

Case Study: A QA team continues to perform manual regression testing for every software release, even though it is time-consuming and inefficient, simply because it has been the tradition within the organization.

Avoidance Strategy:

  • Foster a culture of continuous improvement and innovation in QA.
  • Encourage the team to challenge established practices and explore more efficient alternatives.
  • Introduce automated regression testing tools and techniques to streamline the testing process and improve overall productivity.
  • Regularly evaluate the effectiveness of existing practices and be open to adopting new approaches when necessary.

⑧ Straw Man Fallacy

This fallacy occurs when someone misrepresents or exaggerates an opposing argument or viewpoint in order to make it easier to attack or dismiss.

Case Study: During a QA meeting, a tester proposes using a specific testing framework to enhance test coverage. Another team member misinterprets the suggestion and presents a distorted version, claiming that it would require a complete rewrite of all existing test cases. The team then dismisses the idea based on this exaggerated representation.

Avoidance Strategy:

  • Foster effective communication and active listening within the QA team.
  • Encourage individuals to accurately represent each other's ideas and viewpoints.
  • Promote healthy discussions where ideas can be debated constructively.
  • Emphasize the importance of seeking clarification and avoiding assumptions before making judgments or decisions.

⑨ Post hoc Ergo Propter hoc Fallacy

This fallacy occurs when a causal relationship is assumed between two events solely based on their sequential occurrence, without considering other potential factors or evidence.

Case Study: During performance testing of a web application, the QA team notices a significant increase in response time after a recent software update. They immediately conclude that the update caused the performance degradation without considering other factors such as increased user load or network issues.

Avoidance Strategy:

  • Promote a systematic approach to performance testing and analysis.
  • Consider multiple factors that can influence performance, such as hardware capacity, network conditions, and user behavior.
  • Conduct thorough investigations and gather sufficient data before attributing performance issues to specific causes.
  • Use performance monitoring tools to capture relevant metrics and analyze the impact of different variables.



By understanding and avoiding these fallacies, software QA professionals can elevate their approach, enhance critical thinking, and ensure more effective decision-making. Recognizing the impact of fallacious reasoning in testing processes enables QA teams to adopt evidence-based practices, foster open-mindedness, and ultimately deliver higher quality software. Embracing a culture of continuous learning and improvement, QA professionals can safeguard against fallacies and pave the way for more robust and reliable software applications.

Happy testing!

Naman Garg

Written by Naman Garg

Manual and Automation Tester | Quality Promoter | Technology Leader | Lifelong Learner | Software QA Engineer | Product Manager | Scalable Product Builder | Robust Solution Creator | Business Goal Achiever | Social Volunteer