Keywords

1 Introduction

The Great East Japan earthquake was a large-scale disaster caused by an earthquake off the Pacific coast of Tohoku in March 2011, along with the accompanying tsunami and aftershocks. People’s disaster preparedness awareness (DPA) had increased after the Great East Japan earthquake. In an DPA survey (WEB survey) conducted in 2013Footnote 1, approximately half of the respondents answered that a “large-scale earthquake disaster will occur soon;” however, they also answered that “Although consciousness increased after the Great East Japan earthquake, it has faded slowly.” In general, DPA increases immediately following the occurrence of a disaster; however, preparedness diminishes over time. Moreover, there exists the possibility of a Tokyo Inland earthquake and Nankai Trough earthquake occurring in the future.

Following the Great East Japan earthquake, it became clear that “the limit of public help” by administration itself was affected, and we recognized that, if self-help, mutual help, and public help do not mesh well, disaster control measures are not effective after a large-scale disaster. In the results of the “consciousness of self-help, mutual help and public help measures” of the Public Opinion Survey on Disaster Preparedness (Cabinet Office of Japan), the rate of “we should correspond to placing emphasis on public help” decreased from 24.9% (N = 2155) to 8.3% (N = 3110) in 2002, that of “we should correspond to placing emphasis on self-help” increased from 18.6% to 21.7%, and that of “we should correspond to balancing self-help, mutual help, and public help” increased from 37.4% to 56.3%Footnote 2. Civilians can only practice self-help and mutual help, because public help is carried out by administration. Studies on DPA have been conducted for a long time, and have confirmed that it is improved through traditions and school education [1]. Many studies on DPA have placed emphasis on mutual help, with school education on disaster preparedness and disaster prevention drills in the community being mutual help targets.

In terms of self-help, many people believe it is possible that a large-scale disaster will occur; however, people who do not make preparations for a disaster are in the majority, according to the survey on awareness of and activities related to disaster management in daily activities (May 2016)Footnote 3. Regarding reasons for lack of disaster management, the survey results show that “lack of time,” “lack of opportunities,” and “lack of information” were frequently referred to. From the survey results, it was considered that management may be effective in the case of those who referred to a lack of time, in the form of contacting people during activities on which they are already spending time as an effective measure to raise awareness. In the case of those who referred to a lack of information, providing information in an easier-to-understand way could be beneficial, while in the case of those who referred to a lack of opportunities, the Internet may be an effective measure (see Footnote 3).

Twitter was used as a medium for obtaining disaster information when the Great East Japan earthquake occurred [2], and the Special Committee for New Strategy Promotion reported on issues and objectives for effectively utilizing Twitter and other social network services (SNSs) for disaster preparedness and reductionFootnote 4. Based on the case in which Twitter was used for disaster preparedness and reduction, many local governments and organizations have opened Twitter accounts for sending disaster information, and conducted disaster drills using TwitterFootnote 5. Younger age groups show a higher tendency not to prepare for disasters; however, the usage rate of Twitter is 31.0% (N = 2000), and in particular that of people in their 20s is 52.8% (N = 400), so the usage of young people is higherFootnote 6. Twitter is an SNS that people use daily, and not only for transmitting information at the time of a disaster, but it may aid in disaster preparedness and reduction, and therefore may be a motive for continuing and improving DPA among younger age groups.

It is clear that the continuation and improvement of disaster preparedness is essential. Therefore, we have distributed the “disaster preparedness four-frame comic (DPFFC)” to provide knowledge pertaining to disaster preparedness by using comic expressions via Twitter. The DPFFC aims to continue and improve DPA by helping users to acquire disaster preparedness knowledge in daily life via Twitter, and may aid with self-help during disaster response.

In this study, we consider the possibility of continuing and improving disaster awareness by combining Twitter, which is used in normal time, with comic expressions that have a significant learning effect. We analyzed Tweet activity for 30 episodes (approximately 3 months) in terms of whether DPFFC was likely viewed and obtained user responses. In addition, by providing disaster preparedness knowledge to users, we conducted a questionnaire survey on whether the DPFFC continues and improves their DPA.

2 Related Work

2.1 Relationship Between Twitter and Disaster

Many studies have analyzed the use trend of Twitter, and propagation and spread of Tweets [2, 4,5,6]. Sakaki et al. [4] and Miyabe et al. [5] compared Tweets at the time of a disaster between regions. Liza et al. gathered examples when the Canterbury earthquake struck the South Island of New Zealand with a moment magnitude of 7.1 on September 4 2010, as well as when the Great East Japan earthquake occurred, and analyzed Tweets by means of hashtags. Adam et al. [2] analyzed Tweet spreads at the time of the Great East Japan earthquake and raised the problematic point of the authenticity of retweeted information.

We carried out analysis using Tweet activity, rather than hashtags, retweets or networks that are generally used in Twitter analysis. These studies show how the Twitter usage pattern changes at various points during a disaster’s occurrence. Since the 2016 Kumamoto earthquake occurred while distributing the DPFFC, we analyze differences in usage between before and after the earthquake by using the Tweet activity.

2.2 Comic Learning Effect

Matt et al. described the learning effects of comic expression [3]. Comics can promote reader understanding through interaction between text and illustration, and is often used for education. Furthermore, a comic is expected to have the effect of added attraction. Jay et al. investigated the learning effects of comics in the science field, and found that they are effective as a medium for communicating information to students [7], especially non-science students.

These studies placed importance on the learning difference between comics and text, and applied the experimental procedure of performing a test after learning by means of using a comic at educational sites. Since the DPFFC is distributed via Twitter, we did not use it at educational sites; however, its aim is to continue and improve DPA by helping users to acquire disaster preparedness knowledge in daily life through Twitter. Tweets are displayed on the timeline by following the relative account or being retweeted by other users; however, whether they are read depends on user decision. The same applies to other SNSs, such as Facebook. Matt et al. and Jay et al. investigated comic effects in the environment using experimental and education situations; however, they did not study services in daily use, such as SNSs.

3 Disaster Preparedness Four-Frame Comic

3.1 Disaster Preparedness Four-Frame Comic

The DPFFC is a four-frame comic for learning about disaster preparedness and reduction. It is aims to continue and improve DPA by sharing this knowledge with many users, and helping people to acquire disaster preparedness knowledge in their daily lives via Twitter. According to Matt et al. [3] and Jay et al. [7], the DPFFC may promote users’ understanding and add attraction by using comic expression to distribute disaster preparedness knowledge. The contents are created by referring to high-certainty information distributed by the government or universities, such as Disaster Management, Cabinet Office of Japan.Footnote 7. Distribution is adjusted adjusting to seasonal trends, and news on disasters or disaster preparedness, among others.

Fig. 1.
figure 1

Episode 29, “Japan’s rainfall is double the world average.”

Full size image

Table 1 shows the distribution days and contents of the DPFFC up to June 23, 2016. Since episode 3, we had distributed the contents every third day. We adjusted the contents from damage overview to the 2016 Kumamoto earthquake from episode 8, and that of flood damage to the approaching rainy season from episode 22. Figure 1 shows an example of the DPFFC for episode 29, “Japan’s rainfall is double the world average.”

Table 1. Distribution date and contents of distributed DPFFCs.
Full size table

3.2 AkariMapBot

To distribute the DPFFC, we developed AkariMapBot (@AkariMapBot)Footnote 8, which is a Twitter bot that detects users moving and provides disaster preparedness information, such as shelter and AEDFootnote 9. The number of AkariMapBot followers was 112 at the distribution time of episode 1 (March 22), and 135 at that of episode 30 (June 23).

4 Analysis of Tweet Activity

We analyzed how the DPFFC was shared by means of Tweet activity provided by TwitterFootnote 10.

4.1 Tweet Activity

In Tweet activity, impressions and engagements are provided along with the number of retweets and likes. Impressions are the amount of times a user receives a Tweet in the timeline or search results, while engagements are the total number of times a user interacts with a Tweet, and include retweets, replies, follows, likes, links, cards, hashtags, embedded media, username, profile photo, or Tweet expansion.

Twitter analysis often makes use of retweets or networks [4, 5]; however, these do not show private user responses. Since impressions are the number of displayed Tweets and are counted without a distinction being made between public and private accounts, they can be used as an indicator that a Tweet has been viewed. Engagements are the total count of user responses, without distinction made between public and private accounts, including not only retweets, but also likes and click counts of hashtags, among others; therefore, we can analyze user response details. However, it is possible that Tweets may be skipped by certain users, as impressions provide only the number of displayed Tweets. In addition, we can only refer to the Tweet activity of our own account, and not other accounts.

4.2 DPFFC Tweet Activity

We analyzed whether the DPFFC was possibly browsed and received user responses. Figure 2 shows the impressions transition of the DPFFC, while Fig. 3 shows its engagements transition. We could not acquire data on April 16 and 17 in Figs. 2 and 3. There were cases where the acquired Tweet activity decreased from the previous day, and greatly increased compared to the next day. The value of them never decreased, because the impressions were the number of displayed Tweets, and the engagements were the total user response count. We removed the data from the results in this case.

Fig. 2.
figure 2

The impressions transition of each DPFFC

Full size image
Fig. 3.
figure 3

The engagements transition of each DPFFC

Full size image

The impressions and engagements of episode 7 were lower than those of episodes 4 to 6, considering that episode 7 was distributed on April 15, after the 2016 Kumamoto earthquake that occurred on April 14. Important information communications were overloaded with other Tweets due to the large mass information regarding unrelated disaster areas being posted when the Great East Japan earthquake occurredFootnote 11. Because of this, it is possible that users may have selected information related to the disaster area of the 2016 Kumamoto earthquake. Episode 7 covered a shift to high elevation and tide embankment at the time of tsunami reconstruction, and its contents were not related to the 2016 Kumamoto earthquake. Therefore, it may not have been assessed as important information, and it is possible that impressions and engagements were low. Furthermore, Twitter Japan reported that Tweets related to the 2016 Kumamoto earthquake numbered approximately 26.1 million within one week, which is approximately 23 times the number of Tweets within a week immediately following the Great East Japan earthquakeFootnote 12. Therefore, it is possible that, due to overloading of other Tweets, those of DPFFC were not seen.

After episode 8, the contents of the DPFFC were adjusted according to the disaster damage situation of the 2016 Kumamoto earthquake. In addition, one of the authors (with approximately 1,000 Twitter followers) retweeted the DPFFC Tweets. AkariMapBot, which distributed the DPFFC, has only around 100 followers. We decided that AkariMapBot alone could not distribute disaster-related information to a sufficient number of users in disaster situations; thus, the author retweeted the Tweets.

From episode 8, the impressions and engagements of episodes were higher than those of other episodes, and were increasing even after several days. A great deal of user reactions were obtained, because people had an increased interest in disaster immediately following the occurrence of the 2016 Kumamoto earthquake. We distributed the contents according to the earthquake situation phase, such as episode 8, “Recognition that a local government staff are the same victims,” and episode 11, “Securing a good living environment for the evacuation life.” However, the impressions and engagements the episodes decreased since episode 11. Therefore, it is possible that users’ interest in disaster increased more than usual immediately following the 2016 Kumamoto earthquake, but this has gradually faded.

Episode 16 had higher impressions than other episodes; however, engagements were roughly the same as those of episode 9. Although both episodes 9 and 16 were retweeted 8 times, 3 were from private accounts in episode 8, and 2 from private accounts in episode 16. Many more private accounts retweeted episode 9 than episode 16, which appears to have influenced episode 16. Since episode 16 had 5 likes, compared to episode 9 with 0 likes, it is possible that episode 16 had a great deal of interest.

The contents of the DPFFC changed to flood disaster-related during the rainy season, from episode 22. From episode 11, the impressions and engagements decreased; however, these values increased when we changed the contents for the rainy season. Therefore, we can conclude that users’ interest may be increased by adjusting to seasonal trends. Although the extent of the damage was local to the Kumamoto and Oita Prefectures, disasters during the rainy season may cause damage throughout Japan; in other words, many users may suffer from such disasters and therefore take it more seriously.

Although episodes 24, 26, and 30 were not related to rainy season disasters, their impressions were relatively high, which indicates that decreased user interest may be prevented by distributing contents other than seasonal trends.

4.3 Tweet Activity of Scenarios

We compared the DPFFC with its scenarios to investigate the extent to which the impressions and engagements of the DPFFC were viewed and responded to by users.

The scenarios correspond to each episode of DPFFC, and they were distributed from episode 7. In addition, one of the authors retweeted since episode 15, in order to verify the influence of their retweet on the DPFFC. The scenarios have a distributed image format, because the number of characters per Tweet is limited to 140.

Fig. 4.
figure 4

The impressions transition of each scenario

Full size image
Fig. 5.
figure 5

The engagements transition of each scenario

Full size image

Figure 4 shows the scenario’s impressions transition, while Fig. 5 shows its engagements transition. There were cases in which the acquired Tweet activity decreased from the previous day, and greatly increasing the following day. As with the comic, we removed the data from the results in this case. We could not acquire data on April 16 and 17 in Figs. 4 and 5.

The comic in Fig. 2 has higher impressions than the scenario in Fig. 4. Similarly, the comic in Fig. 3 has higher engagements than the scenario in Fig. 4. The impressions were increased as a result of the retweeting by one of authors after the scenario of episode 15; however, the engagements in Fig. 5 increased less than those in Fig. 3. As a result of the author’s retweets, the scenario Tweets were displayed to many users; however, many did not respond.

Because the scenario was distributed since episode 7, and retweeted since episode 15 by one author, it includes situation differences, such as distribution and retweeting time. However, we believe that the changes in Figs. 2 and 3 were influenced more by many users having interests in the comic than by one author’s retweets.

From the results, we found that the impressions and engagements values of the comics were higher by comparing between the comic and scenario during the Tweet activity collection period from April 12 to July 3.

4.4 Tweet Activity of Regular Posted Tweets

We compared the DPFFC and regular posted Tweets of AkariMapBot, in order to investigate the degree to which the impressions and engagements of the DPFFC were viewed and responded to by users.

Figure 6 shows the impressions of the regular posted Tweets, while Fig. 7 shows their engagements. The regular posted tweets were Tweets posted by AkariMapBot on a regular basis. For example, “Introduction of the functions: If you post such as “I’m at Wakayama University” or “I came to Tokyo Skytree,” this bot provides disaster preparedness information in your area.” Every point of Figs. 6 and 7 plots the impressions and engagements for each Tweet acquired on July 3 in the order of date of posting, without plotting the same Tweet data.

Fig. 6.
figure 6

The impressions of regular posted tweets

Full size image
Fig. 7.
figure 7

The engagements of regular posted tweets

Full size image

There are cases that increasing impressions in Fig. 6, and engagements in Fig. 7. This is because there are tweets that were retweeted on regular posted tweets. The comic in Fig. 2 has higher have impressions than the regular posted tweets in Fig. 6. The comic in Fig. 3 has higher have engagements than the regular posted tweets in Fig. 7. As these results, we found that the impressions and engagements values of the comics were higher by comparing between the comic and the regular posted tweets during the Tweet Activity collection period from April 12 to July 3.

According to the Tweet activity of the regular posted tweets and those of the scenario in Sect. 4.3, we expect the DPFFC to be capable of adding attraction on Twitter, as with the results of Jay et al. [7] and Matt et al. [3]. Therefore, there exists the potential to incorporate learning into daily life by combining SNSs that are used daily, such as Twitter, with comic expression.

5 Questionnaire Survey

We conducted a questionnaire survey following the distribution of episode 10, to evaluate whether the DPFFC continued and improved users’ DPA. The questionnaire survey was conducted using a paper answer sheet and Google FormsFootnote 13. There were 28 participants who were following AkariMapBot, namely 1 teen, 26 people in their 20s, and 1 person in their 30s.

5.1 Questionnaire Survey on DPFFC

The results of the question “Did you look at the disaster preparedness four-frame comic that distributed by AkariMapBot?” were as follows: 3 people answered “I have looked at all the episodes,” 23 answered “I have sometimes looked,” and 2 answered “I have never looked.” The two answers of “I have never looked” were removed from the questionnaire results, due to their lack of reliability.

Table 2 shows the results of the DPFFC questionnaire. We used a five-point Likert scale for evaluation, in which the individual responses were 1: Strongly disagree, 2: Disagree, 3: Neutral, 4: Agree, and 5: Strongly agree.

Table 2. Results of questionnaire about DPFFC
Full size table

Table 2 (1) indicates that for the question: “You acquired disaster preparedness knowledge by looking at disaster preparedness four-frame comics,” the median and mode scores were both 4. In the free description field of the questionnaire, many participants commented, “Disaster preparedness knowledge is included.” The following comments pertain to the provision of disaster preparedness knowledge using comic expression.

  • “Because it is easier to see than text with only typographical characters, the frequency of touching information increased.”

  • “It is easy to understand, because it can be learned on a communication basis.”

  • “I do not think of reading text that is written redundantly about disaster preparedness; however, I was able to read it with interest through comic expression. It is easy to understand.”

Furthermore, one participant commented regarding the provision of disaster preparedness knowledge via Twitter: “It is helpful that information is provided on Twitter, which I am frequently watching.” However, in the free descriptions of participants who answered “Disagree,” there were the following comments: “There are many contents that I already know,” and “The amount of information and sentences were big.”

Table 2 (2) shows that for the question: “You got a starting point for disaster preparedness awareness by looking at the disaster preparedness four-frame comics,” the median score was 3 and the mode score was 4. In the free description of participants who answered “Agree,” there were the following comments: “My consciousness worked because there are contents that take up timely topics, such as the 2016 Kumamoto earthquake,” and “Because I thought that it is not easy to notice when I suffer a disaster and think myself into a state of panic.” In addition, participants who evaluated the ease of using comic expression made the comment: “The comic was easy to watch.” However, in the free description of participants who answered “Disagree,” there were the following comments: “If it is measures and knowledge that can be used immediately after reading, the consciousness may change. However, the contents were knowledge at the time of disaster, therefore it was not triggered watching the comic.” Even in the free description of participants who answered “Neutral,” there were the following comments: “Because there are no contents that apply to myself, it is hard to have a sense of danger.”

As a result of these two questions, we concluded that it is possible for DPFFC to continue and improve DPA, because it may be capable of adding attraction to users and promoting understanding of disaster preparedness knowledge by using comic expression. Although using knowledge of the Great East Japan earthquake in the DPFFC may enhance user awareness, certain users remained unaware because they were not affected by the disaster. Therefore, it is necessary to be careful about which information is handled as the subject of the DPFFC.

5.2 Questionnaire Survey About DPA and Action

We investigated whether DPA and actual action are linked. We provided a free description field for the question “Have you taken any disaster preparedness measures by watching the disaster preparedness four-frame comic?” There were 22 people who answered “I have never taken anything” or left the description blank. The free descriptions of the people who took some disaster preparedness measures were as follows.

  • “I began to check evacuations at travel destinations.”

  • “It gave me a chance to see various websites, because I felt that I wanted to study anything I do not understand in the comic, and know about actions, etc. at the time of disaster.”

  • “I examined some evacuations near my house.”

  • “I tried to know the state of the 2016 Kumamoto earthquake, and confirm the truth of disaster information that was posted at the time of the earthquake.”

The motivation for confirming the shelter is providing shelter information as disaster preparedness information by AkariMapBot that distributed the DPFFC.

In the questionnaire, we could not determine decreasing DPA, because it was conducted only one month after the distribution of episode 1, and the period was short. However, it is possible that the DPFFC can continue and improve DPA, because there were several participants who took certain disaster preparedness measures.

“Awareness of and Activities Related to Disaster Management” is summarized in the White Paper on Disaster Management in Japan 2016 (Cabinet Office of Japan) (see Footnote 3). Even among people who recognize a high possibility of disaster, approximately 54% do not prepare for disasters, according to the White Paper on “Recognition of the importance of disaster preparedness by awareness of disaster possibility.”

“The gap between disaster preparedness awareness and action” was referred to in the White Paper on Disaster Management in Japan 2008 (Cabinet Office of Japan)Footnote 14. The citizens of Japan are highly interested in disasters, because Japan is prone to disasters including earthquakes, tsunamis and floods. However, it was pointed out that DPA does not necessarily lead to action, and there is a situation known as “A gap between consciousness and action on disaster preparedness.” It is important that citizens’ interest in disaster lead to actual disaster preparedness actions. By providing the DPFFC, a few people actually take disaster preparedness actions; therefore, the DPFFC has the potential to bridge the gap between DPA and action.

6 Tweet Activity and Questionnaire Survey

According the Tweet activity analysis results in Sect. 4, the comic has higher impressions and engagements than the scenario format text. Since both the impressions and engagements were high, we found not only that the Tweets of the DPFFC were displayed on users’ timelines, but that they were watched and responded to by users.

According the questionnaire survey results in Sect. 5.1, we found that the DPFFC can be expected to have effects such as promoting users’ understanding and adding attraction by using comic expression to distribute disaster preparedness knowledge, as in Matt et al. [3] and Jay et al. [7]. Since we found that it is possible to include learning into daily life by combining Twitter and comic expression, we can expect a daily learning effect by providing educational material using comics on other SNSs.

It is possible that the DPFFC can address the reasons provided on Twitter using daily life for the lack of disaster management: “lack of time” and “lack of opportunities.” Furthermore, the DPFFC may succeed in using comic expression as an effective measure for providing information in an easier-to-understand manner than a white paper. Moreover, as a result of the questionnaire on DPA and action in Sect. 5.2, we found that the DPFFC has the potential to bridge the gap between DPA and action, because with the provision of the DPFFC, a few people actually took disaster preparedness actions. Finally, we found that the DPFFC can continue and improve DPA by combining Twitter, which is used in daily life, with comics, which have a high learning effect.

7 Conclusions

In this study, we distributed a DPFFC to provide DPA using Twitter and comic expression. We analyzed Tweet activity to determine whether the DPFFC was likely viewed and obtained user responses. In order to evaluate whether the DPFFC can continue and improve DPA, we analyzed the Tweet activity and conducted a questionnaire survey. Based on the results, we found that the DPFFC can continue and improve DPA by combining Twitter, used in daily life, with comics, which have a high learning effect. In addition, we found that the DPFFC has the potential to bridge the gap between DPA and action.

In the future, we will quantitatively evaluate how learning can be adopted into daily life by combining Twitter and comics by means of a DPFFC.