It is a universally popular belief that success comes from following a set of principles. We often set particular targets and establish certain rules to accomplish them, be it to stay fit, achieve work-related targets, or life goals, for that matter. 

Likewise, testers follow a set of 7 basic principles of testing. Finding a tester oblivious of these testing principles is quite rare; however, at the same time, finding someone who actually understands their importance and how to apply them is also limited.

Although the testing principles have existed for years, many of us may have no idea of the value they add. Some may consider the list merely conceptual information required to pass the certification exam or clear an interview; however, the truth is that every tester applies these principles.

These basic testing principles help the testing teams make the best of their time and effort in making the testing process more effective.

Now, the question is: What are the basic principles of Testing? Read on and find out!

7 Basic Principles of Testing 

It is pretty important to achieve optimum test results while conducting testing without straying from the goal. But how does one ensure that they are following the right testing strategy?

Well, for that, following the best web development practices and sticking to the basic testing principles will definitely help you out. So, let's look at the seven widely practised testing principles.

1. Testing shows the Presence of Defect 

This principle of testing states that testing aims to highlight the presence of defects so that developers can rectify them. Testing makes sure to discover all possible hidden errors that often get overlooked during the development stage to obtain an efficient application.

However, rectifying those errors does in no way validate that the product is now 100% error-free. Instead, testing helps reduce the bugs of an application, and it always goes in favour of the testing team. As we find more and more defects, the probability of a hidden defect still residing in an application reduces; however, testing cannot prove that no defect is present.

For instance, an application may seem to be error-free after going to a different testing stage; however, the user may likely encounter a defect that did not occur during testing.

2. Exhaustive Testing is Impossible

Believe it or not, testing everything is pretty much impossible. One can not test an application from every aspect because inputs and outputs alone have infinite combinations.  

And testing each is not in one’s capability. And this is why no application is 100% accurate. Of course, we can achieve 99% efficiency; however, achieving 100% is technically impractical. No doubt, the testing team works hard to make an application bug-free; however, finding some errors is simply beyond imagination. 

Hence, this testing principle emphasizes that exhaustive testing is impossible. So, instead of going ahead with exhaustive testing, we can use the risks and priorities to focus testing efforts. 

We can test a few test cases and assume that the final application is correct and will yield the correct output in other test cases as well. And, if we have to test every test case, it will only consume more cost, effort, time, etc., which is pretty unrealistic.

3. Early Testing saves Time and Money

The sooner, the better; it fits just right into the process of testing. Early testing is one of the significant factors that add quality to your application. Besides, testing does not necessarily have to begin right after development. In fact, you can test it before coding as well. 

For instance: You can check whether the requirement is feasible or not. Moreover, a tester can suggest to the developer ways to reduce the scope of errors.

Additionally, when we begin the testing process a little earlier, it definitely saves time and cost since the developer understands the entire code and its purpose. 

4. Defect Cluster Together

This principle states that one module contains the most issues, i.e., one component or module may likely be responsible for the maximum number of bugs causing a process's failure.

This is because defects are not evenly spread in a system and are clustered. In other words, most defects found during testing are usually in a small number of modules. 

Based on experience, you can identify such risky modules. But this approach has its own problems, and if the same tests are conducted repeatedly, they will no longer find new bugs eventually.

5. The Pesticide Paradox

This principle holds the concept of variation in testing that states when we use the same testing approach or test case to review the code, it may seem to run well, but eventually, it may fail. 

In other words, if the same test is performed repeatedly, eventually, it will no longer find any new defect to overcome the pesticide paradox.

Therefore, to overcome the “Pesticide Paradox,” test cases should be reviewed and revised regularly. And if required, a new set of test cases can be added, and the existing test cases can be removed if they fail to find any more defects from the application.

6. Testing is Context-Dependent 

This principle states that testing is dependent upon the context, and it is entirely correct. Let's face it; we cannot put testing in a box because every individual application has its own set of requirements. 

Of course, there's a defined process of testing that is the same for all applications. However, the testing approach depends on the type of application. For instance, a health-industry application needs more testing than a gaming application. 

Therefore, testing is all about the context, and the type of testing carried out ultimately depends on the context of the application. 

7. Absence of Error Fallacy 

This principle encourages the tester to validate whether or not the application meets the user requirements.

In other words, it really makes no sense to find and fix errors of an application that is not even meeting the user's perspective. It will all be just a waste. Therefore, we should always first examine the potential of an application

It is pretty likely that the application, which is 99% bug-free, may still be unusable. This can be the case if the application is tested thoroughly for the wrong requirement. 

So, testing is not merely finding defects but also ensuring that the application addresses the business needs. All in all, the absence of error is a fallacy, i.e., detecting and fixing defects does not really help if the application is unusable and does not meet the user's requirements.

Wrapping Up

There you go, folks! That was all about the principles of testing.

Applying these rational principles to your testing can certainly help you get more productive and concentrated and can even help enhance the quality of your overall testing strategy. Besides, by applying even one principle, you will eventually find everything fall into place. 

For instance, testing early in the web development process can definitely help alleviate the “absence of errors” fallacy. And, if testers are involved at the requirement gathering phase, you can ensure that the end product will match the client's expectations.

This way, you can achieve the best efficiency by utilizing your time and endeavors effectively and economically with all these principles combined.

Editor: Richa Sharma

Frequently Asked Questions

The principle of testing is to systematically evaluate a software or system to identify defects, ensure it meets requirements, and deliver a reliable and high-quality product to users. Testing involves validating that the software functions as expected and verifying that it doesn't behave unexpectedly or produce errors.

The five common testing methods are:

  • Manual Testing: Testing performed by human testers without automation.
  • Automated Testing: Testing using automated scripts and tools.
  • Black Box Testing: Testing where you do not have the knowledge of the internal code or logic.
  • White Box Testing: Testing with knowledge of the internal code and logic.
  • Regression Testing: Testing to ensure that new changes haven't affected existing functionality.

Testing principles provide a structured approach to software testing, ensuring that it is thorough, systematic, and effective. These principles help identify defects, validate functionality, and ensure software quality, ultimately leading to more reliable and trustworthy software products.

Quality Assurance (QA) principles are a set of fundamental guidelines and practices aimed at ensuring the quality, reliability, and effectiveness of processes and products. They include prevention over detection, continuous improvement, customer focus, process orientation, risk management, testing throughout the lifecycle, clear documentation, collaboration, metrics and measurement, and feedback loops. These principles guide QA efforts in delivering high-quality outcomes and meeting customer expectations.