People become certified through training and/or passing an exam. Products become certified through testing. Individuals often advertise their status by appending the certification acronym to their name: Jane Doe, RHCE.
Ceritifcations may be perpetual, may need to be renewed periodically, or may be for a specific period of time (e.g., the life-time of the product upon which the individual is certified). Although it is more common in regards to licensure, sometimes as part or whole of the renewal of an individual's certification, the individual must show evidence of continual learning--often termed in the US continuing education or earning continuing education units CEU.
Certifications are offered through a certification body. This is usually a business organization. Sometimes, the organization's business is directly related to the certification, as in a software firm that certifies individuals as competent to use it's products. In other cases, an organization (often a not-for-profit organization) exists wholly, or in large part, to offer a particiular certification. Whatever it's nature, the certifying body determines the policies of the certification program. Potential consumers of a certification wish to understand the nature of the certifying body and the certification process. An individual who bears a designation but appears unable to perform competently is said to be a paper tiger because their resume suggests that they would be more effective than they actually are.
Certifications are very common in industry, and in particular the computer industry. The National Organization of Certification Agencies (NOCA) is a US-based organization which helps certification bodies with information. Many members of the Association of Test Publishers ATP are certification bodies, a segment of the ATP membership which is experiencing strong growth in the late 1990's and 2000's
The exponential growth in the number of computer-related certifications coupled with the relative ease of their acquisition has led to their devaluation in the eyes of many people in the technology field. In some cases, exam content is easily found by certification seekers (see brain dump sites]) allowing them to gain certification without knowing, or even understanding, the concepts being tested. Certifying agencies have responded in various ways. Some have incorporated hands-on testing, although there is no evidence that this reduces cheating or improves reliability or validity. Others have explored anti-cheating methodologies (e.g., Caveon ) or expanded their exam content. Faced with this difficult problem, many certifying agencies have not made any changes.
Listing of Certifications