1. Cummins ISM Reference Data Review Merit Addendum for Cummins Surveillance Panel
August 26, 2009
Jim Rutherford

2. Introduction
One more question to address.
6. What is the impact of industry corrections on merits?

3. 6. What is the impact of industry corrections on merits? (Total Merits)
This chart shows merit ratings for each test with and without industry correction.
Obviously, without corrections merits are higher. And for a number of tests the industry corrections change a test from above to below 1000 merits.
So the industry corrections have a large impact on merits.

4. 6. What is the impact of industry corrections on merits? (IAS Merits)
Similar to the previous chart, this chart shows IAS merit ratings for each test with and without industry correction.
Again, the industry corrections have a large impact on merits.

5. 6. What is the impact of industry corrections on merits
6. What is the impact of industry corrections on merits? (Total and IAS Merits)
But do the corrections change the distributions for oil 830-2?
Not really. These box plots show distribution for tests before and after corrections were implemented. In this chart we combined total and IAS merits. The distributions are far from significantly different for before versus after corrections were implemented. In fact, the distribution for IAS increased slightly (not significantly) after corrections were implemented.

6. 6. What is the impact of industry corrections on merits? (CWL Merits)
Like the charts above, this shows the effect of industry correction on CWL merits for each test.

7. 6. What is the impact of industry corrections on merits? (CWL merits)
This chart shows merit ratings with and without industry correction for CWL.
Again, although the correction has big impact on each test’s merit rating, and there were some very low rating numbers, the difference between distributions before and after corrections were implemented is far from significant.