Since the educational psychologist Edward L. Thorndike began researching English vocabulary lists in the 1920s, formulas for readability have followed the general premise that the more often a reader encounters a word, the easier it is for him or her to remember and understand it. Delineating reading levels and choosing vocabulary lists for educational software—just as for traditional classroom texts—requires careful balance. Software reading content must be difficult enough to challenge students with new words as well as with more complex sentences. Content, however, must remain simple enough for students to be able to complete a software level through reading, concentration and practice.
Educational software should involve an up-to-date approach to readability. First, formula-use should employ major approaches for calculating readability: estimating the number of unfamiliar words versus the number of syllables per word and sentence length. Then, a variety of additional factors should always be considered. Tone, content, organization and design all influence the extent to which students regard a particular text as simple or difficult.
One major purpose of educational technology is to help students practice the most crucial reading skills: figuring out vocabulary from context, while re-enforcing key vocabulary words within a beginning context that demonstrates meaning. These skills should be re-enforced by practice and by the constant interactivity -- including text-to-speech capability -- which software provides. Merit Software’s own reading levels and vocabulary lists are based partly on the Dale List of 3,000 Easy Words, the Harris-Jacobson Core Vocabulary and the EDL Core Vocabulary, along with advice from educational practitioners about current classroom materials.
According to the National Assessment of Educational Progress (U.S. Department of Education, 1998), students at an advanced reading level ought to be able to demonstrate overall understanding, provide literal and inferential information, use background knowledge, draw conclusions, and judge text critically as well as offer answers showing careful thought. Yet learners can only progress to such a point after they have basic skills in place. Merit believes that a major goal of educational software is to address such questions, going beyond what the traditional classroom can do in helping students to bridge the gap.