As different learning methods and educational scenarios highly influence the corresponding outcomes, our aim is to highlight quantifiable discrepancies in terms of the complexity gap between presentations and handouts versus full documents (i.e. academic papers), expressed as concrete factors that directly influence the perceived difficulty. Although there are multiple dependant variables that affect the interpretation of a given topic (e.g., order of presented materials, difference in personal styles if materials originate from multiple authors), we limit the scope of our analysis to solely identifying textual traits that can be automatically extracted from conference papers and their corresponding slide presentations. Our approach represents the starting point for adapting MOOC (Massive Open Online Courses) materials to their target audience in terms of: textual complexity, learner comprehension and content reusability. Therefore, this study performs a detailed comparison using a wide variety of textual complexity metrics as background, ranging from surface, syntactic, morphological and semantic factors in order to grasp the specificities of each material. In other words, our goal consists of providing a set of required metrics for adapting learning materials in order to best suit the underlying educational activities. Preliminary results reflect a strong correlation between the two alternative presentation forms of the same material (papers and corresponding slides) and a similar degree of perceived textual complexity, emphasizing the strong and unitary writing characteristics of the author.