tree 855bb8610c01906b0f7d96f672d78f0d9adb9c74
parent ffd6d2a20ef47c67fe15e5494121f88f516d67ab
author Marc Kupietz <kupietz@ids-mannheim.de> 1788532710 +0200
committer Marc Kupietz <kupietz@ids-mannheim.de> 1788532710 +0200

Document the corrected Log-Dice, the effective window and the auto focus

Three things were left unexplained, and one of them has changed:

LD is now computed as Rychly (2008) defines it, without the window size
factor that used to be applied to f1, so its values are higher than
before, by up to log2 of the window size, and comparable to those of
other tools. This is announced in the info tab.

LDaf is unchanged, as is the resulting order of the collocates, but it is
easily mistaken for Log-Dice of the auto focus window. It is the auto
focus score itself, whose denominator grows with the width of the
selection, which is what makes it sensitive to how concentrated a pair
is, and thus what makes it order collocates usefully enough to serve as
the default order. It is therefore not on the scale of LD and can be
higher or lower than it.

LL, MI, MI², MI³ and nPMI are computed over the positions in which the
collocate actually occurs, not over the whole context window. Calling
these the attested positions, and their number the effective window size,
keeps them apart from the auto focus, which is Belica's term for the not
necessarily contiguous selection of positions that yields the highest
score. Both are visible in the auto-focus column, which marks the
attested positions with a hollow and the selected ones with a filled
square.

Explained in the info tab in both languages, in the tooltips of the LDaf
and auto-focus columns, and the LDaf tooltip now gives the formula.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Change-Id: Id6293c71438d4b42d3a461697c181e3b6a072a83