Assessor selection is based on confirmation of the assessor's technical expertise, successful completion of the training process, and continued satisfactory performance of assessments. The key requirement is knowledge of the technology in the areas the assessors will be assessing. All assessors are required to pass the 4-day A2LA assessor orientation course that includes instruction on ISO/IEC 17025 and on A2LA's policies and procedures for performing assessments.

A2LA lead assessors must be approved by the A2LA Board of Directors (BOD) on a yearly basis. The names of new lead assessors are submitted to the BOD once they have successfully passed the staff evaluation to conduct the technical and quality systems portions of the on-site assessment. Returning assessors must also be evaluated on a regular basis. There were nearly 100 contracted assessors in 2003 and 4 new assessors were added to the assessor corps.

During 2003, 13 additional new assessors were initiated into the assessor training program, all of whom successfully completed the A2LA assessor evaluation process and were approved as lead assessors in early 2004. Over 100 names of additional testing and calibration experts are on file as potential assessors.

More than 100 assessors attended the annual Assessor Conclave in Columbia, Maryland to discuss issues affecting accreditation and to develop policies to further consistency and uniformity in assessments. Measurement uncertainty, traceability, and ISO/IEC 17025 interpretations were the main topics of discussion. Assessors also met with Accreditation Council members and participated in technical committee meetings. Training sessions to orient new assessors and for ISO Guide 65 (to support ANSI's ISO Guide 65 assessments) were held.