This study investigated how reading medium (print vs. digital) and communicative purpose (informative vs. persuasive) shape writing processes and outcomes in integrative academic tasks. Eighty-one university students read three source texts in print or digitally and, after random assignment, produced either an informative or persuasive synthesis within a 2×2 between-subjects design. Keystroke logging recorded pausing across three writing stages, indexing planning, translation, and revision. Text quality was scored with holistic rubrics capturing discourse features and integration of sources. Reading medium significantly influenced pausing: students who read in print paused longer during writing, yet medium had no effect on overall text quality. Task purpose mattered: persuasive tasks yielded higher-quality formal writing, whereas scores reflecting level of source integration did not differ. No interaction between reading medium and task purpose emerged. When controlling for reading comprehension, working memory, and planning ability, the main effects of medium and task purpose remained, but period-specific pausing effects were no longer significant. Findings highlight distinct roles for reading medium and task purpose in shaping writing behavior and performance. The results support cautious causal interpretations and suggest that incorporating digital reading and varying task types may enhance academic writing in higher education, informing curriculum design and assessment.