Understanding the basics thoroughly helps to become expertise in any field. In this blog post, we will see about Black box testing techniques. Black box testing is also called as Behavioral Testing or Specification based Testing or Business-Transaction driven Testing.
What is Black box testing?
Black box testing is one of the Dynamic Testing techniques. It is used to validate the business requirements and system functionality. Test cases are designed ad executed on external specifications without knowledge of how the system has built. Testers do not consider about the internal behavior of the code and the program structure.
Consider a text field which should accepts only number between 18 and 100. It is not possible to write and execute test cases with input data from 18 to 100. It will be time consuming and eats up testers’ effort.
Black box techniques help to optimize the test cases with relevant input data to test. There are three black box testing techniques.
- Boundary Value Analysis
- Equivalence Partitioning
- Error Guessing
Boundary Value Analysis
Boundary Value Analysis (BVA) is a Black box testing technique to optimize the input data for writing test cases. BVA focuses on boundary values of the input data. It has Lower Limit, On the boundary and Upper Limit.
E.g. Credit Card Cash Limit should be from 1000$ to 5000$. Boundary Value Analysis yields:
Tester should consider only the boundary values of lower and upper limit and on the boundary values while Test Case Design.
Equivalence Partitioning is a Black box testing technique to optimize the input data for writing test cases. Equivalence Partitioning is technique which helps testers to consider only data from equivalence classes instead of exhaustive values in the larger class.
E.g. Credit Card Cash Limit should be from 1000$ to 5000$. Equivalence Partitioning yields:
Tester should consider only the values in Invalid Classes and Valid Class while Test Case Design.
Based on the tester experience and intuition test cases can be designed. E.g. Tester can easily identify defects while testing date fields.
Download our simple Boundary Value Analysis and Equivalence Partitioning tool which helps you to understand the concept.