The research genre has specific communicative purposes which require students to understand the tone, generic and disciplinary conventions. The present study explored the potential of thematic progression (TP) to contribute to research argument readability. TP concerns how clauses encode information and how that information is carried forward. Three major types of TP include: (a) constant TP; (b) linear TP; and (c) derived TP. Overuse of constant TP often prevents a text from developing, while linear TP better contributes to cohesion. It was hypothesized that an effective TP pattern, if present, may help graduate students better grasp the gist in research arguments. Two groups of participants, native and non-native speakers of English, were recruited to read six Introductions of varying TP patterns and conceptualize their readability. The results revealed that the TP pattern may not have strong predictive power; rather, fewer information breaks better predict readability. Regardless of TP patterns, heavy themes and rhemes may impede understanding. Static and simple themes also do not facilitate readability. The use of metadiscursive devices may facilitate readability on condition that the themes are informative. Effective lexical chains and marked themes, which signal the ties between clauses, also ease processing.