Test Design Techniques interview questions and answers

Positive and negative testing are two distinct types of software testing. Positive testing focuses on validating that the software functions correctly, while negative testing focuses on validating that the software functions correctly when invalid data or scenarios are entered.

Positive Testing:

• Involves testing the software with valid inputs, expecting valid outputs.

• Tests are designed to ensure that the application works as expected and that all functionalities are working correctly.

• Tests are designed to validate the functional specifications and requirements of the application.

Negative Testing:

• Involves testing the software with invalid inputs, expecting invalid outputs.

• Tests are designed to identify any potential defects that may occur when invalid or unexpected data is entered into the application.

• Tests are designed to identify any potential bugs or flaws that may exist in the application.

• Tests are designed to identify any potential security threats or vulnerabilities that may exist in the application.

For example, a positive test for a login form would be to enter valid username and password to test for successful login. On the other hand, a negative test for the same login form would be to enter invalid username and password to test for unsuccessful login.

Designing a test case is an important part of the software testing process. It is the process of creating and defining the set of conditions under which a test can be conducted to determine if the system or application is working as expected. The test case should be designed in such a way that it will cover all the areas of the application and provide a thorough assessment of the system's capabilities.

The process of designing a test case involves the following steps:

1. Identify the objectives of the test: The main objective of the test should be identified first. It could be to check the system's functionality, performance, usability, reliability, etc.

2. Understand the requirements: Next, you should have a clear understanding of the system's requirements. This includes the functional and non-functional requirements.

3. Identify the test conditions: Identify the set of conditions that need to be tested, such as data input, user interface, etc.

4. Design the test cases: Create the test cases that will test the conditions identified in the previous step. Make sure that the test cases are comprehensive and cover all the areas of the system.

5. Execute the test cases: After designing the test cases, you need to execute them to check if the system meets the requirements.

6. Analyze the results: Finally, analyze the results of the test cases and see if the system meets the objectives of the test.

For example, if you are testing a website, you will need to design test cases to check if the website is responding well to user requests, if the navigation is working properly, if the user interface is intuitive and user-friendly, etc.

The best way to ensure the quality of my tests is to implement an effective test design process. This process should involve the following steps:

1. Identify the test objectives: To ensure quality, it is essential to clearly define the testing goals and objectives. This helps to ensure that the tests are designed to meet the objectives and verify the desired functionality.

2. Analyze test requirements: After the objectives are identified, it is important to analyze the requirements of the tests. This includes identifying the test environment, the types of tests necessary, the data needed for the tests, and the resources needed to conduct the tests.

3. Develop test cases: Once the test requirements are analyzed, test cases should be developed. Test cases should include detailed steps for conducting the tests, the expected results of the tests, and the criteria for determining success or failure.

4. Execute the tests: After the test cases are developed, they should be executed. This involves running the tests in the test environment and verifying the expected results.

5. Analyze the results: Once the tests are executed, the results should be analyzed. This includes looking for patterns in the data, identifying any anomalies, and verifying that the tests were conducted properly.

6. Report the results: After the tests have been executed and analyzed, the results should be reported. This includes documenting the results, including any patterns or anomalies found, and providing recommendations for any changes that may be necessary.

By following these steps in the test design process, I can ensure that my tests are of the highest quality.

The most effective way to create a test plan is through a combination of analysis, design, and implementation. This involves analyzing the software requirements, designing test cases, and then implementing the test cases.

Analysis: The first step is to analyze the software requirements to determine the desired functionality and identify potential risks. This includes understanding the use cases, data models, and the overall system architecture.

Design: Once the requirements are understood, test cases can be designed to cover the different areas of the software. This includes creating test scenarios, setting up test data, and creating test scripts.

Implementation: Finally, the test cases need to be implemented. This includes setting up the test environment, running the tests, and recording the results.

Example:
To create a test plan for a web application, one could follow the following steps:

1. Analyze the software requirements - understand the use cases, data models, and system architecture.

2. Design test cases - create test scenarios, set up test data, and create test scripts.

3. Implement the test cases - set up the test environment, run the tests, and record the results.

4. Document the test plan - document the test cases, test data, and results.

5. Update the test plan as necessary - update the test cases and test data as needed.

Test conditions are the basis of test design and help determine the scope of testing. To identify test conditions, I would use the following techniques:

1. Equivalence partitioning: This technique divides the inputs of a system into partitions of equivalent data from which test cases can be derived. It helps to reduce the number of test cases needed to adequately test a system.

2. Boundary Value Analysis: This is a test design technique that helps to identify test cases that lie along the edges of an input domain. This technique helps to identify unexpected behavior of the system when special values or boundary values are used as input.

3. Decision Table Testing: This technique focuses on the relationships between multiple inputs and outputs to determine the correct output for a given set of inputs. It is used to identify all valid combinations of inputs and the associated outputs.

4. State Transition Testing: This technique is used to identify all valid transitions between states in a system. It is used to identify all valid paths through the system and to identify any unexpected behavior when transitioning between states.

5. Use case Testing: This technique is used to identify test cases that cover the full functionality of a system. It is used to identify all valid paths through the system and to identify any unexpected behavior when transitioning between states.

Finally, I would review the system requirements to ensure that all test conditions are identified and that all test cases adequately cover the system requirements.

Test design techniques are methods used to develop and choose test cases that will result in effective testing. Common techniques include boundary value analysis, equivalence partitioning, state transition testing, use case testing, decision table testing, and cause-effect graphing.

1. Boundary Value Analysis (BVA): This technique involves testing the boundary values of inputs, outputs, and internal variables. It is based on the assumption that errors are more likely to occur at the boundaries of the input domain.

2. Equivalence Partitioning (EP): This technique divides input and output data into partition that contain valid, invalid, and boundary values. EP assumes that if one test case from a partition is executed correctly, all other test cases from that partition are also valid.

3. State Transition Testing (STT): This technique is used to validate that the program changes state properly in response to inputs and events. The test cases are based on a state transition diagram that describes the system's states and associated transitions.

4. Use Case Testing: This technique is used to validate functional requirements. Test cases are derived from use cases, which are descriptions of how the system should behave when a user performs a specific action.

5. Decision Table Testing: This technique is used to validate logical conditions and combinations of inputs. Test cases are derived from a decision table, which contains conditions and associated outputs.

6. Cause-Effect Graphing: This technique is used to develop test cases based on an analysis of the system's causes and effects. Test cases are derived from a cause-effect graph, which describes the relationships between inputs and outputs.

Equivalence class testing is a software testing technique used to reduce the number of test cases that must be executed. It is a division of inputs into classes of data from which test cases can be derived. Equivalence class testing involves identifying equivalent data that can be used to represent a larger set of data. With this method, the test engineer can identify representative data from the pool of data values to reduce the number of test cases to be executed.

For example, a user may be asked to enter their age. While the user can enter any integer between 0 and 120, the test engineer can divide the possible inputs into three equivalence classes:

1. Class 1: Ages 0-9

2. Class 2: Ages 10-59

3. Class 3: Ages 60-120

Therefore, the test engineer only needs to execute three test cases (one for each class) instead of 121 separate test cases.

In addition, equivalence class testing is a type of boundary value analysis, where the boundaries of the classes are tested. For example, the boundary between Class 1 and Class 2 is age 10. The test engineer should execute a test case to ensure that an age of 10 is correctly classified in Class 2.

Boundary value testing is a software testing technique which involves testing extreme values or edge cases that lie along the edges of the input domain. It is a way of validating the accuracy of the system by testing the boundary values of the input domain. Boundary values are values that lie at the edge of the input domain. This technique is used to ensure that the system is functioning as expected.

For example, if the input domain consists of values between 0 and 100, then the boundary values would be 0 and 100. The purpose of boundary value testing is to uncover any bugs that may occur when the system is confronted with values that lie at the extreme ends of the input domain.

Steps for Boundary Testing:

1. Identify the boundary values for each input domain.

2. Create test cases for each boundary value.

3. Execute the test cases and observe the system’s response.

4. Analyze the results and verify that the system behaves as expected.

5. If the system does not respond as expected, then the bug must be fixed.

When deciding which test cases to automate, there are several factors to consider.

First, the frequency of execution - are there certain tests that are run repeatedly or are they one-off tests? Automating frequently-run tests can save time and resources.

Second, the complexity of the test - if a test requires multiple steps and/or needs to be run against multiple data sets, automating the test can help to ensure accuracy and consistency.

Third, the cost of automation vs manual testing - if the cost of automating a test is higher than the cost of manual testing, it may not be cost effective to automate.

Finally, the importance of the test - if a particular test is critical to the success of the project, it may be more beneficial to automate it to ensure accuracy and completeness.

As an example, let's say you are considering automating a series of tests related to a web-based application. You might consider the following steps:

1. Identify the tests that are executed frequently, or tests that require multiple steps or data sets.

2. Assess the cost of automating the tests versus the cost of manual testing.

3. Determine the importance of the tests to the success of the project.

4. Prioritize the tests that should be automated based on the factors identified.

5. Develop an automation framework and create automated tests based on the prioritized list.

6. Execute the automated tests and measure their success.

7. Make improvements to the automation framework as needed.

The purpose of a test case is to ensure that a system or application meets all of its requirements and functions correctly. A test case is a set of conditions or variables under which a tester will determine whether an application or system functions correctly. It includes a set of pre-defined steps, inputs, expected results, and execution conditions.

A test case should include the following information:

• Test case ID.

• Test case description.

• Pre-conditions.

• Test steps.

• Expected results.

• Actual results.

• Test status.

For example, a test case for a login page could include the following test steps:

• Enter valid user credentials.

• Click on the Login button.

• Verify if the user was successfully logged in.

• Verify if the correct profile page is displayed.

The expected result for this test case is that the user should be successfully logged in and the correct profile page should be displayed.

Test cases are important in software testing because they serve as a guide to testers and developers on how to test the application and what conditions to look for when doing so. Test cases also provide an organized approach to testing, which helps to ensure that all necessary tests are performed and no corner cases are overlooked. By following the steps of a test case, testers can easily track their progress, document their results, and report any issues that arise.