Define raw data in GLP and why it must be preserved.

• A. Processed summary data used for reports.
• B. Original measurements or observations; preserved to verify data authenticity and enable review.
• C. Predicted values from models.
• D. Anonymized data that removes identifiers.

Answer: (B)

Raw data in GLP are the original measurements or observations as they were first recorded during the study, kept in the form in which the data were produced by the instrument or recorder. This includes the actual instrument readings, observation notes, time stamps, sample identifiers, and any supporting records that show exactly what was observed or measured before any processing or interpretation.

Preservation matters because it preserves the authenticity and integrity of the data. With raw data available, investigators and regulators can verify that results are supported by the original observations, reproduce calculations, detect errors or tampering, and review how decisions were made at each step. GLP requires that these records be kept for a defined period to ensure the study remains transparent, auditable, and verifiable.

Processed summary data, while useful for reporting, are derived from raw data and do not provide the unaltered evidence necessary for validation. Predicted values from models come from analysis and do not reflect the original observations themselves. Anonymized data remove identifiers, which can hinder traceability and regulatory review, undermining the ability to link results back to the source records.