4.4.4 Notes on the Different Suggestion Modes
In order to understand what these suggestion modes do, a basic
understanding of how Aspell works is required. For that see
Aspell Suggestion Strategy.
The suggestion modes are as follows.
- ultra
- This method will use the fastest method available to come up with
decent suggestions. This currently means that it will look for
soundslikes within one edit distance apart without doing any
typo-analysis or using replacement tables.
In this mode Aspell gets about 87% of
the words from my small test kernel of misspelled words. (Go to
http://aspell.net/test for more info on the test kernel as well
as comparisons of this version of Aspell with previous versions and
other spell checkers.)
- fast
- This method is like ultra except that it also performs
typo-analysis and uses replacement tables. The typo-analysis brings
words which are likely to be due to typos to the beginning of the
list. This mode should get around the same number of words that the
ultra method does.
- normal
- This method normally looks for soundslikes within two edit distance
apart and performs typo-analysis unless it is turned off. Is is
much slower than fast mode but it returns better suggestions. This
mode gets 93% of the words.
- slow
-
Normally identical to normal.
- bad-spellers
- This method also looks for soundslikes within two edit distances apart
but is tailored more for the bad speller, where as fast or
normal are tailored more to strike a good balance between
typos and true misspellings. This mode never performs typo-analysis
and returns a huge number of words for the really bad spellers
who can't seem to get the spelling anything close to what it should
be. If the misspelled word looks anything like the correct spelling
it is bound to be found somewhere on the list of 100 or more
suggestions. This mode gets 98% of the words.
If jump tables were not used then the normal option is
identical to fast. And the slow option is identical
to the normal if jump tables were used.