It is my humble opinion that everyone who is applying for and has an installer license should have to take an EXAM to receive the License once the interem time has been completed.  An EXAM should be required after so many years to keep it.  There are so many of the current installers in the State of Virginia that cry and complain about the testing requirement and complain that they have been doing this profession for x amount of years.  They still need to be held accountable for their knowledge and proffession and should be glad to take a test to prove they are smart enough to do this job.  As State design requirements and Local Ordinances become more and more complicated these individuals and companies should have to take tests to verify they are qualified.  Experience stated is not as good as experience proven.  I would preffer all be required to test into the Installer License regardless of time on the job.  Just because a guy has been doing this for twenty years (or says he has) does not mean he may know what he is doing very well.  That is all.  Thank You.