 Claims <unk> regarding the legibility and readability of the single and double sentence spacing methods — by proponents on both sides . Supporters of single spacing assert that familiarity with the current standard in books , magazines , and the Web enhances readability , that double spacing looks strange in text using proportional fonts , and that the " rivers " and " holes " caused by double spacing <unk> readability . Proponents of double sentence spacing state that the extra space between sentences enhances readability by providing clearer breaks between sentences and making text appear more <unk> , particularly noting the very small visual difference between a dot and a comma . 
