An annual set of awards recognising the best works of science fiction or fantasy published in the USA during the previous year. They were first awarded in 1966 and are given in 4 categories for different lengths of literary work. Six works are nominated each year between November and February by published authors who are members of the SFWA (although the nominees do not themselves need to be members). Members may then vote on the ballot during March and the final results are presented at the awards ceremony in May.