Presentation for the 1st UK Local Biocuration Conference. Abstract: Background: the exponential growth of bio-literature has stirred the need for digitization of the biocuration processes. In this context, it is observed that screen reading of electronic documents paces up the whole process and also induces collaborative annotation in biocuration1. The usability experiences of screen-reading in the biocuration context are still an under-explored area. In other contexts, studies found that cumbersome navigational issues hamper intensive reading. It results in lower reading speeds (and thus, slower understanding) and fatigue when reading for an extended period, which leads to an increment in curation cost. On the other side, studies found that improvement of the organization of the electronic document can facilitate faster reading and understanding2. Objective: To our knowledge, this is the first and preliminary usability experience study to observe the effect of the navigation through the electronic document structure for the biocuration task. Method: We conduct a curation task with the five curators for eighty papers in front of an eye tracker. We collect the level of difficulty on the Likert scale from the participants and their preferences for document structure. We explore different features for our statistical and correlation analysis: errors made by curators (checked by the other two expert curators), efforts made by the curators measured using an eye tracker. We used several eye tracker features, namely, time spent for reading, time spent for navigation, top-down reading time, bottom-up reading time, reading speed, fixation duration at different parts of the document, and pupillary responses. Result: We find that the concurrent rhetorical and document structure facilitates fast reading. In this case, the navigational effort comes down significantly, especially for the experienced curators. It implies from this study that concurrent rhetorical structure3 and document layout facilitate reading for digital biocuration. While in these experiment we did not see direct signs for explicit structural weaknesses of the paper, we are planning to investigate the impact of structural changes on the readiblity of papers. The key difficulty in this work is obtaining sufficiently large group of test persons able to read complex scientific publications. 1 W3C Web Annotation Working Group. (2022, April 4). To enable a conversation over the world’s knowledge: Hypothesis Mission. https://web.hypothes.is 2 Hornbæk, K., & Frøkjær, E. (2003). Reading patterns and usability in visualizations of electronic documents. ACM Transactions on Computer-Human Interaction (TOCHI), 10(2), 119-149. 3 Teufel, S., Siddharthan, A., & Batchelor, C. (2009, August). Towards domain-independent argumentative zoning: Evidence from chemistry and computational linguistics. In Proceedings of the 2009 conference on empirical methods in natural language processing (pp. 1493-1502).