What type of testing occurs throughout the data analysis process and is not formally documented?

Informal testing is an ongoing and unstructured process that occurs naturally throughout the data analysis lifecycle. Unlike formal testing, which is systematic and follows a documented protocol, informal testing is often spontaneous and driven by the analyst's intuition and experience. It allows analysts to quickly assess data quality, identify anomalies, and refine their insights as they progress.

This type of testing is crucial because it enables practitioners to iterate on their analyses dynamically, catching issues such as errors in data collection or unexpected patterns without the need for formal procedures or documentation. Informal testing is especially useful in exploratory data analysis, where flexibility and adaptability are key. It serves as a way to validate findings in real-time, making it an integral part of the analytical process that complements other more formal methodologies.