CompTIA Data+ DA0-002 (V2) Practice Question

The correct answer is Data drift. Data drift refers to the phenomenon where the statistical properties of the input data for a model change over time, causing the production data to differ from the data the model was trained on. This shift can lead to a degradation in model performance, as seen in the scenario where changes in customer age and session duration distributions are impacting the model's accuracy.

• Requirement testing is incorrect because it is the process of validating that a system or its data outputs meet the initial business requirements. This type of testing is typically performed before deployment, not to monitor the performance of a live model in response to changing data patterns.
• A unit test is a test that verifies the functionality of a specific, isolated piece of code. A unit test failure would indicate a bug in the code itself, not a change in the statistical properties of the live data flowing through the system. The scenario describes a problem with the data's characteristics, not a software bug.
• Source control, also known as version control, is a system for tracking and managing changes to software code, scripts, and other files. It is not a process for monitoring the statistical properties of production data.