When do standard approaches for measuring vocabulary difficulty, syntactic complexity and referential cohesion yield biased estimates of text difficulty?

Abstract

Many widely-used approaches for assessing text difficulty providea single prediction equation that is assumed to hold for texts belongingto a variety of different genres. This paper demonstrates that suchmodels tend to overpredict the difficulty of informational textswhile simultaneously underpredicting the difficulty of literary texts.Mechanisms that may account for these effects are examined. Resultssuggest that the estimated effects can be traced to certain frequentlyused measures of vocabulary difficulty, syntactic complexity andreferential cohesion.