Here are the criteria for the preparation of tables, as specified by the Journal of Clinical Laboratory Science:

• Write table titles at the top of the table.
• Number tables sequentially with Roman numerals.
• Include the following information in a title, whenever possible: who, what, where, why and when.
• Put the independent variable in the left column, and the dependent variable in the right, if you are listing data with independent and dependent variables.
• Label each column with the appropriate units.
• Adequately space tables that appear on the same page.

Example:

Table I Patient specimens analyzed for blood urea nitrogen on the Dimension RxL and the Vitros 250 at City Hospital


Sample #	RxL (mg/dL urea)	Vitros 250 (mg/dl) urea
1	8.8	8.8
2	11.2	10.0
3	12.4	13.6
4	16.2	13.2
5	20.0	21.2
6	25.0	20.0
7	28.8	26.2

In this case, the Dimension RxL is the "reference method" and is considered the independent variable, while the Vitros 250 is the "test method" and is considered the dependent variable.