Verification and validation are two critical aspects of data testing in the context of software development. They are distinct processes, each serving a specific purpose in ensuring data quality and accuracy.
1. Verification
Verification is the process of checking whether the data meets the specified requirements and adheres to predefined standards. It ensures that the data is consistent and correctly formatted but does not necessarily validate the accuracy of the data.
Example: Suppose you have a requirement that all email addresses in your database should follow a specific format, such as “example@email.com.” Verification would involve checking that all email addresses in the database conform to this format as illustrated below.
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2. Validation
Validation, on the other hand, is the process of ensuring that the data is accurate, reliable, and fit for its intended purpose. It verifies the correctness of the data against the real-world scenario it represents. Validation often requires comparing data against external sources or performing calculations to confirm its accuracy.
Example: Suppose you have a dataset of customer ages, and you want to validate it by checking if the ages fall within a reasonable range (e.g., between 18 and 100 years).
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- Verification checks whether the data adheres to predefined standards or requirements (e.g., format, structure).
- Validation checks whether the data is accurate and meaningful in the real-world context.
- Verification is often performed during data input or import processes.
- Validation is typically performed after data has been collected or processed and is used to confirm its integrity.
- Verification helps prevent incorrect data from entering a system.
- Validation helps ensure that the data serves its intended purpose and is reliable for decision-making.
In practice, both verification and validation are essential for maintaining data quality and ensuring that data-driven decisions are based on accurate and meaningful information. The specific tests and checks you perform will depend on your data and its use cases.