I'm being told by an experienced BA (> 25 years) that "Numeric numbers are usually totaled therefore should be right justified." And that text should always be left justified.
I have never heard this before now. Is this a true "standard"?
Yes. English text is usually left-aligned. Numbers are normally aligned so that the various places (unit, tens, etc.) are in columns. If the numbers are integers, this just means right-aligning the numbers. If they have decimal fractions, then the decimal places should be aligned, with the units digits all in a vertical line.
This makes it easy to compare the numbers' magnitudes. Mac OS X gets this wrong in the Finder: File sizes are given in abbreviated form, such as 342kB or 6MB. When reading a file listing, it's hard to spot the 342MB file amongst all the 342kB files.
Yes, this is a "standard". I am >25 too and I know where to look up this guideline :-)
This is guideline 2.3/16 in: Smith S. L., Mosier J. N. (1986) Guidelines for Designing User Interface Software (ESD-TR-86-278), Bedford: The MITRE Corporation | http://www.idemployee.id.tue.nl/g.w.m.rauterberg/lecturenotes/DA308/MITRE(1986)smith-mosier.pdf
Authors provide references to even more older standards downto 1975.
Numbers in a table should be formatted so that digits with the same significance are stacked vertically. While this is often described as "right alignment" or "decimal alignment", there's another scenario I've not seen mentioned: values which sometimes include fractions. For example, if one is listing the dimensions of some components, which column is easier to read:
Bizzler 9¾ 9¾ Bozzler 12½ 12½ Woozler 48- 48 Wizzler 68¼ 68¼ Fozzler 97- 97 Fizzler 125- 125 Feezler 325½ 325½
Lining up the units makes it easier to judge the relative size of the numbers than it would be if numbers with non-zero fractions were pushed left.
While I agree that default for numeric should be right-aligned, I think there are some rare cases where left-alignment makes more sense. One example would be Bank Routing Numbers. The following thoughts together made may think they should be left-aligned:
It looks like the ABA agrees with left-aligning for routing numbers - at least they didn't choose to right-align them in their routing number lookup report
any number that is numeric in nature and a computation is done on it (like a total) then it should ALWAYS be right aligned ALONG WITH its heading. So other numeric number that are just numbers like units, some procedure code, date, etc should be left aligned ALONG WITH its heading.
Yes, text should be left-aligned when in grids. Text labels, are best right-aligned. Research shows that there is less cognitive strain identifying relationship between text label and field when labels are right aligned. But in grids and charts, left-align.