Footnotes in tables (part 1): choice of footnote markers and their sequence
Footnotes often indicate scholarly texts. Although less commonly used in the text now than in the past, footnotes to tables are as common today as they were before, and this post is about how to use them.
A footnote is a pointer; it tells readers that whatever bit of text they are reading requires additional information to make complete sense. For example, a sentence may give the per capita income of a country in the currency of that country – yen or peso or euro, for example – but, through a footnote, supply the rate of exchange against US dollars. Footnotes in tables serve the same function but require a few other considerations, which are covered below.
Footnotes or headnotes: In tables, footnotes are attached to specific cells, including cells that contain column headings or row headings. However, if the contents of a footnote apply to the entire table, it is best to use a headnote, which typically appears after the title of the table but before its body.
A table giving yearly data on the prevalence of different diseases may explain in a headnote, for example, that all the data are based on records of hospitals run by the state and not those of private hospitals. A particular cell in that table, however, may carry a footnote saying that the figure for that particular disease in that particular year was based on records from private hospitals as well as government-run hospitals.
Incidentally, footnotes to a table appear at the foot of that table and not at the foot of the page that contains the table.
Choice of a marker: Commonly used markers for footnotes are the asterisk or the star (*), the obelisk or the dagger (†), the section sign (§), and the paragraph sign or the blind P or the pilcrow (¶). If additional markers are needed, the same marks are doubled (**, ††, §§, ¶¶). However, this system is cumbersome. For tables of numerical data, use letters of the alphabet set as superscripts; for tables that consist of blocks of text, use superscript numerals.
Secondly, * and ** are typically used to identify the level of significance or probability, * being equal to 5% (p<.05) and ** being equal to 1% (p<.01). This is another reason to avoid using * and ** as footnote markers.
Sequence: Assign footnote markers to specific cells in the normal reading order: from left to right as you work your way downwards. In a table comprising five columns and five rows, for example, the last (extreme right) cell in the second row will be marked ¹ or a and the first cell (extreme left) in the fourth row will be marked ² or b.
Click here to read the second part to this article.