Trait Subject Approval Section Installation Section

Marbling Exclusion of carcases 5.3.1.2 5.2

Marbling Stationary 6.1 5.3.1

Marbling Chain speed

Marbling Chain speed

Ribeye Area Stationary 7.1

Fat Thickness Stationary 8.1

Yield Stationary

Yield Stationary

6.2

9.1

5.3.2

5.3.1
Approval Document Installation Document

A final Official Marbling Score will be computed from the 

independent observations for each carcass. Carcass 

data will be excluded from the test if the difference of 

any one of the independent observations exceeds a 

range of three (3) times the root mean square of the 

differences between all independent observations and 

their corresponding average for that carcass.

A mean expert marbling score (MEMS) will be 

calculated. If the mean expert marbling score is greater 

than 30 marbling units from any individual expert call, 

then data from that carcass will not be used. 

95% of the carcasses shall have all three of the 

predicted marbling score observations within 20 

marbling score units of the mean predicted marbling 

score for that carcass. 

95% of all carcass prediction residuals (difference 

between online and offline instrument) shall not exceed 

10 marbling units 

Average residual = 0 + 10 marbling score units where 

the residual is the difference between the predicted 

instrument marbling score and mean expert panel 

marbling score 

R2 value of the marbling residuals (difference between 

USDA mean expert marbling score and the proposed 

facility instrument) ≥ 0.95 

• The standard deviation of the residuals (rSD) from the 

mean expert panel marbling score < or + 35 marbling 

score units; and, 

• Slope of 0 + 0.075, using the residual from the 

MEPMS as the dependent variable (y axis) and the 

average of the instrument marbling score and mean 

expert panel marbling score as the independent 

variable (x-axis). 

The standard deviation of the marbling residuals 

between MEMS and proposed instrument (RSD) ≤ 20 

(Accuracy)

•95% of the carcasses shall have all three of the 

predicted ribeye area observations

within 1.0 square inches of the predicted mean ribeye 

area for that carcass.

(Repeatability)

•95% of predicted ribeye area observations within 0.5 

square inches of the mean of the three ribeye area 

observations for that carcass

95% of all ribeye area measurement residuals shall not 

exceed 0.5 square inches 

95% of the carcasses shall have all three predicted fat 

thickness observations within

0.2 inches predicted mean fat thickness for that carcass

95% of all fat thickness measurement residuals shall 

not exceed 0.1 inches

95% of predicted final yield grade residuals shall not 

exceed 0.5 final yield grade 

The residual standard deviation (RSD) of final yield 

grade shall not exceed 0.25 yield grade units 

R2 = 0.90 or greater
Comment

Different metrics for excluding carcases

Metric for installation document is 2x more accurate 

than approval document

No requirement of R2 in approval document

Standard deviation of residuals is stricter in the 

installation document and approval document

Installation document is more 2x more accurate on 

residuals when comparing technology to expert

Installation document is more 2x more accurate on 

residuals when comparing technology to expert

Completely different metrics between Approval 

Document and Installation Document