Russel,
As part of a larger user-study for my thesis, I compared the two
configurations of unless that you list. I found that users were
significantly more accurate with the first form, where unless is at
the end of the control structure. Please see hypothesis 3 in this
paper:
J.F. Pane and B.A. Myers, "Tabular and Textual Methods for Selecting
Objects from a Group," Proceedings of VL 2000: IEEE International
Symposium on Visual Languages, Seattle, WA: IEEE Computer Society,
September 10-13 2000, pp. 157-164.
http://www.cs.cmu.edu/~pane/VL2000.html
John
On 1/22/07, Russel Winder wrote:
Does anyone know if there is any research on the readability and
comprehensiblity of control structures such as:
<statement> if <condition>
<statement> unless <condition>
as compared to:
if <condition> <statement>
unless <condition> <statement>