## 4 Experiments
### Readability Evaluation  
The purpose of this application, which deals with life stories, is to free caregivers from the manual task of organizing life stories and reduce the difficulty they face in obtaining useful information from these stories. Therefore, the overall readability of the life story event tree is crucial as it affects whether the caregiver can gain some understanding of the older adult through this event tree. Figure 8 displays a partially structured life narrative generated by the LSH-GEFR method. This structured life narrative systematically organizes multiple fragmented life stories in a \"topic-event-life stories\" structure. Within Figure 8, fragmented stories 1, 2, 3, and 4 describe the same event, amalgamated as event 5, and presented in a \"time + abstract\" format. Simultaneously, interrelated events 1, 2, 3, 4, and 5 cluster into topic 2 and are presented in a \"time + keywords\" format. In addition to the above experiments, we conducted a user evaluation to measure the quality of the event trees in terms of logical coherence and overall readability. We invited twelve graduate students from the Gerontechnology Lab of Hefei University of Technology to participate in a survey to evaluate the event tree quality. All twelve participants reviewed all event trees and all event branches in each tree generated by all of the methods to evaluate the logical coherence and overall readability through the following questions [27]. Examples of the event tree for each method used in this evaluation are given in the Supplementary Material Table S1. * Question 1: Do all the events in each topic truly talk about the same topic (yes or no)? * Question 2: Do all the life stories in each event node truly talk about the same event (yes or no)? * Question 3: Do you agree that the event branches are logically coherent for each event tree generated by different methods? Figure 8: The structured life narrative generated by LSH-GEFR is organized in the form of a “topic-event-life story”. * Question 4: Do you agree that the event tree is overall comprehensible for each event tree generated by different methods? We first report the effectiveness of our system for event groups and event merging in the OALS 2.0 dataset. In 76.02% of topics, the events truly talk about the same topic (yes to question 1), and the accuracy of merging life stories about the same events is 75.37% (yes to question 2). Question 3 evaluates the logical coherence of event branches; therefore, each event branch has a score from each participant. Question 4 evaluates the overall readability of each event tree; therefore, each event tree has a score from each participant. Since a seven-point Likert scale is utilized, we count the percentage of each score for each question. A higher percentage of the higher score denotes better performance. The results and descriptive statistics of each participant's evaluation are shown in the Supplementary Material Table S2. Figure 9 illustrates the cumulative distribution functions (CDFs) of the percentages of event branch consistency scores for different algorithms. As we can see from Figure 9, the CDF curve of LSH-GEFR is above the curves of other methods. This indicates that the event branches generated by LSH-GEFR have the best logical coherence. Specifically, more than 84.91% of event branches of LSH-GEFR achieve scores higher than four. LSH-GEFR generated significantly more coherent event branches. The aim of the automatic organization of older adult life stories into an event tree structure is to reduce the difficulty for caregivers to manually organize the life stories and derive useful information from them. The event tree reflects a synopsis of an older adult's life experience. Therefore, the overall readability of the event tree influences the caregiver's insight into older adults. Table 6 shows the overall readability score percentages for different event trees. We can find that the event tree generated by LSH-GEFR has the best overall comprehension.