The degree or diploma is just an insignia recognized for the purpose of employment per se. These do not measure the intrinsic worth or calibre of a person. Acquisition of knowledge and updating is a continuous process for all creations in the world but not for humans alone. It is high time that diplomas or degrees are delinked for the purpose of employment in which case number of persons who would acquire diploma or degree becomes insignificant. Also, there is no universal recognition of diploma or degree acquired in a given country. Thefore it is a futile exercise to think of fixing an expiry date for any diploma or degree or similar distinction.
