A description is given of the cloze procedure, which has been used to measure the readability of many different types of written materials such as textbooks and works of literature. It assesses readability by measuring readers' success in supplying deleted words that have been replaced by blanks. The procedure was used to test the readability of an IEEE standard, and the results are compared with readability scores for the same work computed by other formulas.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The multidimensional nature of usability (including tradeoffs between dimensions) is described, stressing the linkage of the concept to the effective use of documentation by a particular group of readers in performing a certain set of software-related tasks under realistic environmental constraints. Major issues in the evaluation and design of usability are examined. It is argued that the sampling of realistic tasks and target readers is often very difficult, particularly in a laboratory setting, and that additional emphasis must be placed on using multiple observation periods, standardized measures and materials, and multimethod assessments of usability.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>