Treffer: Determining readability by computer analysis using the Fourier transform to calculate the spatial frequencies of words

The black and white pattern formed when an individual word is printed on a page was analyzed by the Fourier transform. The Fourier transform produces a sequence of sinusodial functions, usually called spatial frequencies, whose amplitudes depend upon the particular pattern analyzed. These amplitudes were examined to determine if the amplitudes of the spatial frequencies with particular frequencies indicated a level of readability. An extensive literature search indicated that there were no studies using the Fourier transform to study the readability of words. There were, however, many studies that indicated a renewed interest in a fast and easy method of determining readability. Words for this study were randomly chosen from Dale's 769 Word List, easier words, and Fry's word list of Spelling Demons, harder words. The data from the statistical analysis of the amplitudes of the spatial frequencies of these words correctly predicted whether the word was on the hard list of words or on the easy list of words with over 80 percent accuracy.