The International comparison of biochemical data often is fraught with this problem. Something as simple as this can ruin any possibilities of any type of comparative analysis. The question concerning cigarette consumption presents more interesting problems. The above example raises several important additional facts about computer database types. Option a would appear fine if everyone where clear about the time interval involved, this is really another aspect of the unit of measure situation described above.
Option b is more complex.
Here we have a set of words which clearly represent ordered divisions on a scale of some sort. This process of assigning a code to a fact of some sort is called coding . Key Point Coding is a very important activity allowing standardised input and facilitating analysis of data. It is also a major part of questionnaire construction where a list of codes are produced in what is called a coding frame . The topics of oral hygiene, attitude to nurse prescribing and adult learning disability are complex problems for they all probably consist of multiple data items each of which would need a set of codes.