Final answer:
Visual observations should be included when evaluating supplement elements instrumentally to ensure accuracy and reliability of the results.
Step-by-step explanation:
When evaluating supplement elements instrumentally, it is important to also include visual observations to ensure accuracy and reliability of the results. Visual observations can provide additional information about how the media, slides, tubes, etc. appear during the test. This helps in verifying the instrumental measurements and identifying any discrepancies or anomalies that may arise.