A software development team can perform black box and white box testing processes to remove errors from a program's coding language and enhance the quality of a final product. It's important for a software professional to understand how these processes work to include them in a development process successfully. By learning about the difference between these tests, you can determine which options can best address your needs.
Understanding black box vs. white box testing
When attempting to understand the difference between black box vs. white box testing, it's helpful to look at what each testing method is.
Black box testing
Black box testing is a software testing method whereby the tester doesn’t know the internal structure of the item being tested. Black box testing is a functional test of the software and doesn’t require programming knowledge to execute. It’s essentially testing the program to see if it’s functional and doesn’t test to see if the program does what they designed it to do. Black box testing isn’t time consuming and can be done using trial and error. For example, searching keywords on Google to test their position in the search ranking can be considered black box testing.
White box testing
White box testing is a software testing method in which the tester is aware of the internal structure and design and they are testing the functionality of it. White box testing is a structural test of the software and is typically carried out by software developers with extensive knowledge of software programming. This style of testing is time-consuming to complete and tests the logic of the software. For example, inputting data and testing to see if your program produces the correct output can be considered white box testing.
The differences between black box vs. white box testing
Here are the key differences between black box and white box testing:
Software testers and developers
A key difference between black box testing and white box testing is the person who carries out the testing. Typically, software testers complete black box testing while software programmers execute white box testing. This is because white box testing requires a higher programming knowledge as each line of code is being tested to see if it’s functional. Black box testing requires less knowledge of programming as only the outcome is being tested. Many companies hire external software testers for black box testing to control what information they receive, reducing the possibility of bias in their evaluation processes.
Usability vs. coding success
Another difference between black box and white box testing is the perspective of the tester. Developers design black box testing to focus on whether the future customer can successfully use the software, so the tester typically takes on the perspective of the customer. This means black box testers may use similar devices and mimic behaviours of the future consumer. White box testing focus only on successful implementation of the software. Developers conduct evaluations from their own perspective and use all necessary internal tools to address coding errors, improving a program's overall capabilities.
Input and output vs. code pathways
In black box testing, a user typically performs a task to test is the desired outcome is achieved while in white box testing, an individual examines an aspect of a program's code to ensure each line works sequentially and has the correct value or type of data. Black box testing looks closely at the outcome of an event, while white box testing looks at the process required to get that same outcome. Black box and white box testers are looking at two distinct parts of the process to evaluate different aspects of the program.
Short-term vs. long-term process
Black box testing takes a shorter amount of time to execute compared to white box testing. Black box testing is only testing the outcome of the program, while white box testing each line of code that goes into the program. When a person conducts a black box test, they only test features a company chooses, meaning the developers determine the length of each evaluation. White box testing, however, might involve an in-depth analysis of different sections in a program's code, which is a detailed process that may require a lot more time to complete overall.
Manual methods vs. automated trials
Black box testing often requires some coordination between testers and software developers. As black box testers discover problems with the outcome of the program, they may need to communicate with programmers to establish the location of the problem in the code. White box testers can often use automated software to test the functionality of their code and focus on problem areas when the automation identifies them. They may conduct manual tests to isolate certain errors in a section of code but more often use technology to accomplish their tasks.
Program evaluation vs. structural testing
Black box testing involves running software to evaluate its functionality and performance. A tester may explore a program's various features through different trials and log errors they encounter to ensure it's ready for future customers. A white box testing, however, requires an individual to analyze individual lines of a coding language to check for errors and determine ways to improve its features. If a black box test uncovers an additional error, you can use a white box testing procedure to determine which area of code potentially caused it.
Types of black box testing
Here are a few types of black box testing processes:
Functional testing
Functional black box testing is concerned only with the function of the program and focuses on how well the system carries out its functions. For example, a tester may review whether you can log in to a network using the correct identification.
Non-functional testing
This type of testing focuses on specific aspects of the function and not on the overall functionality of the program. This type of testing aims to establish which aspects are not functional and how they relate to the overall readiness of the system. They typically carry this type of testing out after functional testing has discovered any errors in the program.
Regression testing
Regression testing is carried out to test if changes have solved a problem. After black box testers run their evaluation, they can send any errors back to the programmer for revision. Regression testing re-tests the program to ensure all errors are resolved and that the program is functional.
Types of white box testing
Here are a few types of white box testing processes:
Unit testing
Unit testing is often the first type of white box testing carried out. The programmer carries unit out. It’s used to catch any errors before the programmer continues with the code. Unit testing catches most of the errors and stops errors from building up as the code progresses. They may also perform it between other tests to check if new errors arise.
Static analysis
Programmers run this type of test to determine if each line of code is functional, meaning other lines of code can use its output to perform their functions. This type of testing doesn’t test the overall functionality of the code, it focuses solely on each line of code. For example, if a source code contains the correct font size and type, it can show up in a program's text.
Statement coverage
They generate static testing tests internal coding and infrastructure of the program to see how many successful outputs. They can check this value against the total number of outputs to see if any are non-functional. It's a formulaic value that allows a developer to design the parameters for other white box test cases.
Benefits of white box testing
Here are some benefits of white box testing:
Optimizes a program's code
Programmers can use white box testing procedures to discover errors and make alterations. Programmers can determine the best strategies for improving the functionality of the code and its performance.
Presents a clear evaluation structure
White box testing requires a defined framework and clear rules to work successfully. As a result, a project team can better predict when they can finish a testing process, allowing them an ability to make more accurate product release plans.
Streamlines test process creation
A tester often creates evaluation scenarios directly after receiving a program's final specifications. Black box testing allows testers to quickly discover errors and make suggestions for the development team to revise and implement.
Benefits of black box testing
Consider the following benefits of black box testing:
Access to multiple perspectives
A tester may have different information about a program than a software programmer or engineer, so they can identify more areas of improvement. They may also primarily work in a different industry, meaning they can target a product's usability to various groups of people.
Improves a program's specifications
Black box testers can identify ambiguous wording in a program's requirements, which describe a list of features it must have to achieve its intended purpose. If a project team clarifies these requirements, they can create more precise features.
Streamlines communications
As white box testing is frequently conducted internally, there is already established communication and relationships within a business. This allows communication to be streamlined, as less there can be fewer questions and all parties often operate in the same building.