Then the monitor asks a harder question: "Where is the source for this participant's self-reported exercise frequency?"

The coordinator pauses. The exercise frequency was collected verbally during the screening visit and entered directly into the EDC system. There is no separate paper record. There is no printout to pull. Is the CRF itself the source? Is the coordinator's memory of the conversation the source? The answer depends entirely on a decision that should have been made before the first participant was ever enrolled -- a prospective determination of what would serve as source for each type of data in the trial.

That moment of uncertainty -- a competent coordinator, a reasonable question, and no clear answer -- illustrates why this lesson exists. Knowing what qualifies as a source document is not an academic exercise. It determines whether your data can survive source data verification, and ultimately, whether they can survive an inspection.

Then the monitor asks a harder question: "Where is the source for this participant's self-reported exercise frequency?"

The coordinator pauses. The exercise frequency was collected verbally during the screening visit and entered directly into the EDC system. There is no separate paper record. There is no printout to pull. Is the CRF itself the source? Is the coordinator's memory of the conversation the source? The answer depends entirely on a decision that should have been made before the first participant was ever enrolled -- a prospective determination of what would serve as source for each type of data in the trial.

That moment of uncertainty -- a competent coordinator, a reasonable question, and no clear answer -- illustrates why this lesson exists. Knowing what qualifies as a source document is not an academic exercise. It determines whether your data can survive source data verification, and ultimately, whether they can survive an inspection.