## 4 Discussion
### Merits of Highlighting New Information  
The performance in extracting relevant information was significantly improved when new information in progress notes was highlighted. Text highlighting enhances not only searching but also reading performance [28]. In addition, the highlighting of new information may help users relieve  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Testing Scenario with** & **Testing Scenario with** & **P** \\  & **Original Notes** & **Highlighted Notes** & \\ \hline Task demands & & & \\ Task time, min & 30.7 (29.0–36.0) & 28.7 (25.1–34.1) & 0.060 \\ Mouse click & 132.0 (91.5–169.5) & 116.0 (76.5–176.0) & 0.195 \\ Mouse wheel & 1060.5 (726.0–1147.0) & 797.5 (665.0–1124.5) & 0.308 \\ Mouse movement, 10\({}^{3}\) pixels & 195.4 (133.8–286.9) & 166.6 (124.5–275.6) & 0.209 \\ Task Performance & & & \\ Admission note & 92.5 (87.5–100.0) & 95.0 (92.5–100.0) & 0.374 \\ Progress notes & 85.0 (80.0–95.0) & 95.0 (90.0–100.0) & 0.003 \\ Overall & 90.0 (82.5–93.8) & 95.0 (91.3–98.8) & 0.003 \\ Perceived Workload & & & \\ Mental & 70.0 (60.0–82.5) & 62.5 (45.0–70.0) & 0.003 \\ Physical & 62.5 (30.0–75.0) & 37.5 (22.5–52.5) & 0.007 \\ Temporal & 70.0 (57.5–80.0) & 50.0 (42.5–62.5) & 0.003 \\ Performance & 30.0 (20.0–52.5) & 30.0 (20.0–50.0) & 0.471 \\ Effort & 72.5 (67.5–85.0) & 60.0 (50.0–75.0) & 0.003 \\ Frustration & 50.0 (20.0–70.0) & 30.0 (20.0–50.0) & 0.038 \\ Overall NASA-TLX & 62.0 (55.5–71.3) & 50.2 (43.3–61.0) & 0.003 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Comparison of task demands, task performance, and perceived workload between scenarios using original notes and highlighted notes.  
information overload and concentrate on new information. The effect of highlighting can probably be explained by the psychological theory of human information processing. As proposed by [PERSON] and [PERSON] [29], \"controlled processing\" of information allows humans to read and understand information but requires attention and thus has limited capacity. Their experiments showed that when targets and distractors become more similar, the search tasks become more difficult, especially when the number of distractors increases. Similarly, the excessive redundant information in clinical notes can cause information overload and attention deficit. The highlighting of new information increases the contrast between targets and distractors, leading to a decrease in information overload and improvement in clinical reasoning.  
Although a nonsignificant decrease in the time to completion was observed when highlighted notes were reviewed, there was no difference in mouse usage between testing scenarios. The possible reasons are as follows: First, clinical notes, whether highlighted or not, were presented to users in full rather than summarized form. Second, all the participants are trained healthcare professionals. They are accustomed to browsing the whole content of clinical notes to extract relevant information. Third, participants might not be confident in the accuracy of highlighting. Therefore, they would rather thoroughly review the clinical notes than skip non-highlighted redundant information.  
It is worth noting that, despite similar task demands between testing scenarios, the overall perceived workload as assessed using the NASA-TLX was significantly reduced when new information was highlighted. Interestingly, the perceived overall performance, one of the six dimensions of the NASA-TLX, did not change between testing scenarios (Table 3). This dimension measures how successful the subject is in performing the task and how satisfied the subject is with their own performance. In the user experiment, even though the participants believed they performed equally well in both scenarios, they actually did worse according to the scores of task performance (Table 3). In other words, the participants were totally unaware of how the increased workload had affected their performance.