Granularity of data
The level of granularity depends upon the need of user. Different users (skilled, semi-skilled or novice) may demand different level of granularity. For example, when a patient wants to check his blood pressure report, he may be interested in knowing whether the blood pressure is normal, high or low, but when a physician wants to check the blood pressure reports, he wants to see the details of systolic and diastolic blood pressure. Different views of data should be maintained based on the user.