There is no singular scoring rubric for application evaluations. SmarterSelect gives you the opportunity to create your own scoring parameters so that you may find the perfect applicant based on your program's requirements and goals.
In terms of scoring methodology, many of our clients use a Likert Scale (http://en.wikipedia.org/wiki/Likert_scale) to allow their evaluators to give a qualitative assessment of an application item, such as an essay, which can ultimately be reduced to quantitative data to make for easier reports and analysis.
Because grading essays is ultimately subjective, clients almost always use an ordinal scale (such as having an evaluator with a batch of five applications look through applicants' answers side-by-side and defining them as 1st, 2nd, 3rd, et cetera) to rank them (http://en.wikipedia.org/wiki/Level_of_measurement), while items with clear numeric value, such as GPA and test scores can be assessed using an interval scale (i.e., an ACT score of 31-36 is worth 6 points, 25-30 is worth 5 points, and so on).
How deeply involved and scientific you want to be with your scoring rubric is completely up to you, but SmarterSelect is designed to allow you to create any scoring method you desire.