Towards Universal Accessibility on the Web: Do Grammar Checking Tools Improve Text Readability?

Readable text is a key ingredient in a universally accessible web. WCAG2.1 recommends that text should be readable by someone with basic schooling, a criterion that is hard to quantify and implement. Writers rely on qualitative clear-language recommendations, their own experience, and tools. This study set out to investigate if one class of such tools, automatic grammar checkers, has a measurable effect on the readability of text. A controlled experiment was conducted employing 15 participants who brought a piece of their own writing to the experiment tasked with improving the text using a grammar checker. Changes in readability of the text before and after applying the grammar tool were measured. Results show that there were significant reductions in error rates by applying the grammar tool, while there were no significant effects on readability. The results suggest that other automatic tools beside grammar checkers are needed to improve readability. These results have implications for web content providers.