Ever wondered why electronic voting machines, used in four Lok Sabha elections and 127 assembly polls since 2004, are not deployed in polls to elect the President and Vice President of India, members of Rajya Sabha, and members of state legislative councils? The EVMs are based on a technology where they work as aggregator of votes in direct elections such as the Lok Sabha and state assemblies.

Voters press the button against the name of the candidate of their choice and the one who bags the maximum number of votes is declared elected. But the election of the President is held in accordance with the system of proportional representation by means of single transferable vote. In accordance with the system of proportional representation by means of single transferable vote, every elector can mark as many preferences, as there are candidates contesting the election.