Term	Definition
Error consistency	Two measures:
	1. Percent consistency of error location
	2. Percent variability of error type
1. Consistency of error location	Degree to which sound errors occur in the same target sound three or more times across trials
	Calculated by dividing the number of sounds consistently in error (within a word type) by the number of total sounds in error
2. Variability of error type	Degree to which sound errors differ from each other within the same location of a word
	Calculated by dividing the number of errors that differ from each other within the same location of a target word across trials by the total number of errors produced within the same location of the target word across trials
Error rate	Mean number of sound errors per word for each participant
Error type	Number of specified error types (six types) produced by each participant
1. Distortions	An attempt at the target phoneme that does not cross the phoneme boundary, produced with perceptible place, timing, manner, or voice deviation from accurate production
2. Distorted substitutions	A production that not only crosses phoneme boundaries of the target phoneme, but is also distorted
3. Distorted additions	An inserted nontarget phoneme that is distorted
4. Sequential substitutions	Phonemic perseveration, anticipation, and transposition errors
5. Nonsequential substitutions	Phonemic errors other than sequential errors, influenced by factors outside the target word
6. Addition	An inserted nontarget phoneme that is phonetically accurate (not distorted)
7. Omission	A deleted phoneme