Details About the Calculation of ASVAB Scores
How is the ASVAB Score Calculated?
ASVAB is a series of tests accepted by all the branches of US armed forces for recruiting and classifying candidates. The test is used as a career exploration tool as well by thousands of high school and senior school students every year. Though there are no different versions of the test for different purposes and branches of armed services, the score requirements usually vary. Therefore, if you are a potential ASVAB candidate, it is always important for you to understand the scoring requirements. Read on to find more about how the ASVAB scores are calculated.
What are ASVAB Scores?
The ASVAB test consists of nine (in the paper and pencilbased version of the test) or ten (in the computer adapted test version) subtests depending on the version of the test offered to you, at the MEPS or MET site of test administration. However, the scoring process ensures that scores are linked through an equating process and you are not, in any way, gaining or losing because of the test version taken.
There are two main types of ASVAB scores:

 The Armed Forces Qualifying Test (AFQT) score, which is a combined score of only four subtests of the battery. This score is used to determine the eligibility for enlisting by all the force branches, with different minimum score criteria.
 The overall ASVAB score of the entire battery. The overall score is grouped further into clusters or lines or qualifying areas for classifying candidates into appropriate job areas and roles.
For more on the ASVAB test and the scoring in general, refer to:
How are the ASVAB Scores Calculated and Reported?
The ASVAB scoring is based on the Item Response Theory (IRT) model where the candidates’ abilities, the questions, and the scores are placed on the same scale. The model allows the test to be customized according to the performance of individual examinees. The IRT model is based on a threeparameter logistic (3PL) model (parameters being the difficulty level of the question item, discrimination power of the item, and guessing probability for the item).
The 3PL model is utilized for both versions of the test to estimate the final ability approximation of the examinees. In the computer adaptive version of the test (CATASVAB), the threeparameter logistic model is also used to select questions based on the examinees’ performance levels. Each testtaker’s ability is updated after every question, and when the test concludes or the given time limit is over, the final ability estimate is computed using the Bayesian modal estimate technique.
In case of the traditional P&Pversion ASVAB, any unanswered items are considered as incorrect responses, and if a candidate does not complete the test within the time limit, a penalty is applied related to the number of questions not attempted and certain other factors (http://officialasvab.com/understand_res.htm).
Once the final ability computation is done, the scores are converted into standard scores. This is done by standardizing the individual scores against a nationally representative sample based on the national norms available (http://officialasvab.com/norming_rec.htm). For more information on how the standard scores are calculated, refer to http://officialasvab.com/docs/1997score_scale.pdf. For determining the AFQT score or the eligibility to enlisting, the standard scores of the following four subtests only are combined:
 Arithmetic Reasoning (AR)
 Mathematics Knowledge (MK)
 Paragraph Comprehension (PC)
 Word Knowledge (WK)
In the ASVAB calculator, the AFQT scores are reported in percentiles (199). For example, an AFQT score of 90 indicates that the candidate has performed as good as or better than 90% of the representative sample. And the scores are then grouped into AFQT categories (http://officialasvab.com/understand_rec.htm).
The total ASVAB scores further grouped into various clusters or lines are used for the classification of selected candidates into appropriate job functions. The AFQT score criteria and ASVAB line score requirements are different for the various branches like army, navy, air force, marines, and the coast guard. For more information, refer to the respective armed force branch website, or refer to: http://officialasvab.com/military_rec.htm.
Salient Features of Calculation of the ASVAB Scores
Here is a list of important points to remember in this regard:

 The way the scores are calculated equalizes any differences in the nature and methods of administration, thereby ensuring that the scores mean the same across all its versions.

 Across different administration ways or versions of ASVAB, the scores are statistically connected. This is done using a process called equating.

 Individual scores of the subtests are never used, but are compared against the representative sample scores before being utilized for enlisting and classification purposes.

 The scoring process uses proven statistical methods for calculating the final scores of the examinees.
 The penalty function in the calculation of ASVAB scores reduces the possibility of unnaturally increasing the scores by using trainable strategies.