Here are two papers about whether reader comprehension is better with paper than screens. They reach opposite conclusions.
E-readers, Computer Screens, or Paper: Does Reading Comprehension Change Across Media Platforms?
Sara J. Margolin, Casey Driscoll, Michael Toland, Jennifer Little Kegler
Reading linear texts on paper versus computer screen: Effects on reading comprehension
Anne Mangen, Bente R. Walgermo, Kolbjørn Brønnick
Suppose you wanted to try to find an answer. Please design an experiment to measure reading on different modalities, specifically Kindle/paper/audio. Here are some of the choices you’ll need to address:
Do you want to measure comprehension or retention?
Do you want to measure speed or accuracy?
Do you want to study children, college students or adults?
Do you want to experiment with non-fiction or fiction materials?
Do you focus on second-language learners or native speakers?
Do you use “easy” or “difficult” materials (eg as measured by grade level)?
Do you want to use long or short materials – books or articles (or novels vs short stories)?
Are you evaluating reader choice – what do they want – or reader performance?
This is why you can get lots of different answers.
Please write two pages or so outlining the experiment you have in mind.