Positive Testing vs Negative Testing | Scenarios & Approaches

Software testing is the process of evaluating and confirming a software program to ensure it functions as intended. It is designed to provide that a program works as intended and to discover flaws before it is used. There are two main methods for testing software,- Positive Testing and Negative Testing.

In this article, I will discuss positive testing vs negative testing – clearly distinguishing between them with examples to help you write good test cases for your software programs.

Difference Between Positive Testing and Negative Testing

Positive testing ensures that software performs as it is expected to do. When writing test cases for positive testing, only legitimate (valid) inputs are provided as inputs. 

In Negative testing, a software program is evaluated against false or incorrect data. Negative testing is also known as error path testing or failure.

Read More on Negative Testing

Positive Testing vs Negative Testing – Examples Test Scenarios

Let’s simulate a software program with a Password text box field allowing users to enter passwords between 8 and 15 alphanumeric characters.

See the table below for various positive and negative test scenario examples.

Positive Test Scenarios	Negative Test Scenarios
The Password text box should allow 8 characters input.	The password text box should throw an error or should not accept when less than 8 characters are entered.
The Password text box should allow 15 characters of input.	The password text box should throw an error or should not accept when more than 15 characters are entered.
Any values between 8 and 15 characters long should be accepted by the Password text box.	The password text box should not accept special characters as input
It should accept any combination of letters and numbers in Password text box.	The password text box should not accept acombination of numbers only or acombination of letters only.

Positive Testing VS Negative Testing

In this session, let us discuss some key differences between positive and negative testing.

Positive Testing	Negative Testing
Positive testing examines a software program’s response with the help of a valid input data set.	Checking the software program’s response using the invalid/incorrect input data set is known as Negative testing.
Positive testing is not a guarantee of high-quality software.	It ensures that the software product is of high quality.
Positive testing is executed quicker.	It takes more time to execute compared to that positive testing.
Positive testing is used consistently to validate the set of test cases that are currently available.	It is used consistently to break the software program (product) with an unidentified set of test cases we will use.
Positive testing’s primary goal is to ensure that the software application consistently complies with the developer’s software requirements specifications (SRS)	This testing’s primary goal is to evaluate a software program’s consistency in the face of erroneous validation data sets.
Positive testing does not cover all possible scenarios.	It encompasses all possible scenarios.
It is a process where the program is validated against a reliable input data set.	It is a process where the program is validated against the invalid input data set.
Positive testing has less impact than Negative testing.	It is more crucial and significant than Positive testing.
Positive testing can be implemented on all kinds of applications.	It can also be performed on all kinds of applications.
Someone with less knowledge can carry out the positive testing.	Professional software testers mainly use negative testing.
It makes sure that the software program meets the required standard.	It makes sure to deliver 100 percent bug-free software.
Positive testing is implemented only for the predicted conditions.	It ensures that the software is completely bug-free.

Positive and Negative testing are two opposing test methods—as the name suggests—but they are also very effective at producing high-quality and bug-free software in the end.

Testing Approaches Used.

The following basic techniques are used to verify positive and negative test cases.

• Equivalence Partitioning
• Boundary Value Analysis

1. Boundary Value Analysis

This software testing approach creates test cases keeping border values in mind. When the input data is used inside the boundary value constraints, this is referred to as positive testing. This is known as negative testing when the input data is chosen outside the boundary value restrictions.

Example: All other characters (Special Characters) will be nullified for a software program that accepts Alphanumeric characters only. The boundary data sets [a, b, 2, 5] and [&, %, ^, @] will be used to write test cases in this technique.

2. Equivalence Partitioning

This software testing method divides input data into numerous sections. Testers must verify the values of each partition at least once. Partitions with valid values are used in positive testing, and negative testing uses partitions with wrong values.

Example: All other characters (Special Characters) will be nullified for a software program that accepts Alphanumeric characters only. We have two divisions in our test cases, all alphanumeric values and all special characters.

The test case may take a pair of alphanumeric values and a special character from each section to write in this technique. i.e. (a, $) or (2, @)

Conclusion

We may conclude that testing ensures that the application is devoid of bugs before it is launched and helps create high-quality software applications after seeing the direct comparison between the two testing methods .ie, Positive Testing vs Negative Testing.

Both testing ensures that the application meets the provided business requirements and standards and gives us sufficient assurance in the software’s quality.

Both testing ensure enough confidence in the program’s quality.

Hence, using both testing methods provides sufficient certainty about the quality of an application (Final Product).

Finally, we can assert that positive and Negative testing is like the two halves of a coin, implying that we cannot ignore anyone’s importance under any circumstances.

Read More – The Different Software Testing Types Explained