I didn't realise that Joe had made a comment here (Oct 31st 2007) or else I would have replied sooner. Sorry, Joe!
David seems to have made a very subtle distinction between legibility and readability, which I don't quite understand, because aren't these two words synonymous?
The basic "rules" of typsetting that I have been taught are:
1) Serif fonts are (generally) easier to read than sans-serif fonts, everything else more or less being equal (e.g. size, leading, tracking, contrast, etc)
2) In order to keep lines of text readable it is recommended to keep line lengths approximately equal to two consecutive lower case alphabets (i.e. the space occupied by typing a to z twice without any spaces), irrespective of the typeface used.
3) Line spacing (or leading, rhymes with 'ledding') should be approx 120% the size of the typeface used, and is one of the major keys to readability/legibility/ease of understanding.
4) Paragraph spacing aids the reader in understanding and separating blocks of thought, though not actually an aid to reading.
These issues relate to Accordance as follows:
1) The Accordance User can choose whatever font they have on their Mac.
2) It is unlikely to be an issue.
3) This is what some users are requesting to be able to adjust manually, similar to the way most word processors allow the user to adjust the line spacing irrespective of the typeface used.
4) This functionality is already available to some degree.Factors affecting readability:
a. Choice of typeface (style or design)
b. Size of typeface
c. Colour of typeface and of background, degree of contrast between the two
d. Leading or line spacing
e. Paragraph spacing
It seems to me that what is requested here is more control/greater flexibility in areas © and (d). David has hinted at © being in the works for version 8.
Joe's comment maintaining "different fonts do make for different lead spacing and can be a big help" is partially accurate (it depends on the typeface) but perhaps misses the point that users are requesting the functionality to change the leading independently of changing the typeface.
Bear in mind also that these "rules" have been established for print media, so screen resolution and monitor brightness are not factored in.
God bless you!
Edited by Alistair, 22 April 2008 - 04:03 PM.