A rubric allows you to select from a list of criteria and incorporate levels of quality rather than a single performance objective. Rubrics provide descriptions of the expectations as well as number or value to measure those expectations.
When establishing a baseline score and at each grading period, the SLP determines which criteria best describes the student and adds up the corresponding numeric point values for each of those criteria.
For example, for a rubric that has a possibility of up to 15 points, a goal could be written that the student will score 14/15 on a rubric. This means that the student needs to earn a total of 14 rubric points for mastery of the goal. 14 out of 15 does NOT represent a ratio.
Whenever using goals that are measured by rubrics, the rubric must be attached to the student's IEP so parents, teachers (and those who may inherit the IEP) can interpret scores.