FAQ: Microsoft Certification Exam Development
“At Microsoft, we strive to ensure that our certifications are relevant, respected, and highly valued within the IT community and that they objectively prove the expertise of technology practitioners. Earning a Microsoft Certification helps demonstrate an individual's comprehension of the latest IT developments and mastery of skills in a specific technology. Microsoft Certifications command great respect in the industry, thanks in part to the thorough and meticulous process used to develop the exams.” Microsoft Certification Exam Development site.
From a statistical perspective, the certification team uses methods approved by the certification industry. You may have noticed that there is a trend for everyone doctors, mechanics, engineers, computer professionals to get certified within their respective industries. The exam development team, in conjunction with a psychometrician, rely on statistics to help ensure that the exam is statistically reliable, questions are at the right level of difficulty (questions that are too easy/too difficult do not contribute to your passing score), and the passing mark is set at the right difficulty level.