I think you’ve probably understood it and have just maybe been confused by the wording of the DEAP!
If I’m correct , I think it’s basically…
Target consonants (141) minus consonants IN ANY WORDS THAT ARE not elicited = total consonants IN ALL WORDS elicited and then minus consonants in error = total consonants correct. This is then converted to a percentage by dividing the number of consonants produced correctly by the total number of consonants elicited x 100.
Does that make sense at all? So basically I think they just mean for you to minus any consonants from words the child maybe didn’t know, so they aren’t used in the total.
So I would think it’s fine to use as a pre and post measure for any speech assessment. If you were using the CLEAR and the child didn’t attempt “knot” spontaneously then you would minus 2 consonants from your total possible consonants, before adding up how many they actually produced.
Consonants produced correctly DIVIDED BY total consonants in words attempted
Is maybe an easier way?
Hope that makes sense and please someone feel free to correct me if I’m wrong!!