You must assign a field data type to each field of a table, unless you want to use the Text data type that Access assigns by default. One principle of relational database design is that all the data in a single field consists of one data type. Access provides a much wider variety of data types and formats from which to choose than most PC database managers. In addition to setting the data type, you can set other field properties that determine the format, size, and other characteristics of the data that affect its appearance and the accuracy with which numerical values are stored. Table 4.1 lists the field data types that you can select for data contained in Access tables.