Why numeric units are important…

(Subtitled “…and really should be obvious and dimensionally consistent.”)

For example, taken from the Microsoft Excel 2007 locally-installed help documentation (Topic ID: HP01216383):

On a worksheet, you can specify a column width of 0 (zero) to 255. This value represents the number of characters that can be displayed in a cell that is formatted with the standard font (standard font: The default text font for worksheets. The standard font determines the default font for the Normal cell style.). The default column width is 8.43 characters. If the column width is set to 0, the column is hidden.

You can specify a row height of 0 (zero) to 409. This value represents the height measurement in points (1 point equals approximately 172 inch). The default row height is 12.75 points. If the row height is set to 0, the row is hidden.

There are a few problems with this:

  1. When adjusting either the column height or the row height in an Excel spreadsheet, neither unit of measure is shown in the associated dialog box. Therefore, when a user adjusts the height or width, he doesn’t know to what that adjustment is relative.
  2. The units for width and height are different.
  3. The unit for width is relative to characteristics of the font used. The documentation is also not clear, typographically speaking, if this is relative to the font’s em-width or en-width.
  4. The unit for height is absolute.

It would be helpful if Excel showed the related units in the dialog boxes so that users had more of a sense of how a change will affect either the width or height of a cell in a spreadsheet.