On the accessibility of the grayscale version of a PoN-enabled use case notation

The physics of notations (PoN) is a framework for designing cognitively effective notations. Cognitive effectiveness refers to the ease (speed and accuracy) by which model readers read models. In 2019, a PoN-Enabled notation for use case diagrams was proposed. It has been empirically proven that the cognitive effectiveness of this new notation is superior to the original use case notation. The new notation however relies in part on the use of color. The accessibility of this new design has not been validated for use by the colorblind community, or any users who need to use a grayscale version of the models created. The PoN framework was not designed to explicitly account for the colorblind community or users who can only access grayscale versions of models. Inclusivity should not be an afterthought in software engineering practice or research. To this end, this paper empirically evaluates the cognitive effectiveness of the PoN-enabled use case notation in situations where it is viewed in grayscale.