 World Book Company became the first publisher of group-administered tests measuring mental ability when it published Otis’ Group Intelligence Scale in 1918.Otis joined World Book in 1921.By the time World Book merged with Harcourt Brace in 1960, it had a portfolio of educational tests, including the Stanford Achievement Test (1923), the Metropolitan Achievement Test (1932) and the Otis Mental Ability Test (1936).