Why does ASBO report scaled scores instead of raw scores or percentage scores?

In the ASBO system, passing candidates receive a grade of “Pass” only.  No numeric score is provided. 

Failing candidates receive a grade of “Fail” and a numeric scaled score.  Failing candidates receive scaled scores that range from 250 to 599. (Scaled scores of 600 or more are passing scores.)  The closer the scaled score is to 600, the closer the candidate is to passing.  

ABSO reports test results as scaled scores because the process accurately represents relative performance on the test and provides consistent reporting of scores across tests of different length and difficulty.  Since the scales are constant across examinations, all scores have the same meaning and can be compared. 

A scaled score results from the conversion of the number of items a candidate answers correctly on a test to a constant score reporting scale.  On this scale, the worst possible score converts to 250 and the minimum number of correct answers required to pass the test converts to 600.  The failing candidate’s score is then converted to a numeric value along that scale.  


Example:
SFO examination Part I contains 60 scored items, and Part II contains 90 scored items.  There are multiple versions (forms) of each part.  Assume that two candidates take both tests and receive different forms of each part.  Candidate “A” receives scaled scores of 400 on Part I and 550 on Part II, and candidate “B” receives scaled scores of 500 on Part I and 580 on Part II. 

Although the tests are different, the following conclusions can be drawn:
• Candidate “A” performed significantly better on Part II than on Part I.  He/she was close to passing Part II but needs significant improvement before retaking Part I.  
• Candidate “B” performed better than candidate “A”  on both Part I and on Part II.
• Candidate “B” also performed better on Part II than on Part I.  In fact, candidate “B” was close to passing Part II.

When these candidates return to retake these exams, they will receive different examination forms.  They will, however, be able to accurately compare the new scores against the previous scores and will be able to determine how much they have improved.