Although research on readability is still in its infancy, studies have been conducted concerning typographical features, semantic and pragmatic facets, linguistic factors, and orthographic dimensions. This paper discusses readability formulas, pointing out their limitations and listing 13 generalizations about them. The paper also outlines readability variables and concludes that, since structural and tranformational grammar are opening new vistas for research about linguistic factors in readability, psycholinguistic research merits serious consideration by graduate students in different disciplines. (JM)