CNATRAINST 1500.4F

18 May 1999

THE NAVY STANDARD SCORE

The Navy Standard Score (NSS) is a representation of any score

relative to the average score. The scale is artificially

centered at 50 (that is, 50 is average). Each NSS is a whole

number and the scale is truncated at 20 and 80. The formula for

the Navy Standard Score is:

NSS = (((grade - avg grade)/S.D.)10)+50 rounded.

Where

grade = any student grade

avg grade = the mean grade for the distribution in question

S.D. = standard deviation for that distribution

Example: ENS Smith's flight grade is 3.042. The squadron

average is

3.037 with a standard deviation of 0.012.

NSS = (((grade - avg grade)/S.D.)10)+50 rounded

SS = (((3.042 - 3.037)/0.012)10)+50 = 54.1666

NSS = 54

Example:

ENS Smith's academic grade is 83.8%.

The wing average

is

92.17% with a standard deviation of 2.79.

NSS = (((grade - avg grade)/S.D.)10)+50 rounded

SS = (((83.8 - 92.17)/2.79)10)+50 = 20

NSS = 20

CONSTRUCTION OF CONVERSION TABLES

1. Conversion tables for flight and academic grades shall be

identified as to their applicability to TRAWING/squadron, phase

and effective date.

2. Construct tables to show range of grades or scores which

equate to each standard score. For example 3.012 to 3.014 = 47

3. Annotate each table with the number of students used to

calculate the mean and standard deviation, mean, standard

deviation, highest grade in the sample, and lowest grade in the

sample.

4. Each number of the NSS scale represents one tenth of a

standard deviation. The grade which equates to a NSS of 20 is

three standard deviations below the mean. For example, with an

average flight grade of 3.00 and a standard deviation of 0.015, a

flight grade of 2.955 equates to a NSS of 20. One tenth of the

standard deviation is 0.0015. Each NSS is bracketed by that span

of grades. Thus the average grade of 3.00 equating to a NSS of

50 encompasses the flight grade from 2.99925 to 3.00075 or, for

the table, 2.999 to 3.001 = 50.

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