6 Qi Gao, Fabian Abel, Geert-Jan Houben, Yong Yu 百 18.6% 3.1%3.% Table 2. Comparison of syntactic content Fig. 2. Comparison of writing style for in- F2: The results regarding the individual users'access behavior illustrate that twitter users switch between different clients more often than the users on Sina Weibo. This difference in behavior could be explained by the lower overall number of valuable Sina Weibo client applications(e. g. in our dataset .5 different Sina Weibo clients versus 5468 Twitter clients) 4.2 Syntactic Content Analysis Results In Table 2, we compare the syntax of messages posted on Sina Weibo and Twitter and particularly the usage of hashtags and URLs. Overall, 20% of he Twitter messages contain hashtags and 29. 1% of the tweets feature a URL Therefore, the usage of hashtags and URLs on Twitter is 3.2 times and 1.97 times respectively more intensive than on Sina Weibo. The analysis of special charac- ters implies that users on Twitter ask more than twice as many questions than users on Sina Weibo(see question marks in Table 2). In contrast, Sina Weibo users make more extensive use of exclamation marks and therefore more often put extra emphasis on their statements To further analyze the usage of hashtags and URLs, we also plot for each individual user in our samples the average number of hashtags and URLs per post. From Fig. 2, we infer that a considerably high fraction of Sina Weibo users does not mention hashtags or URLs at all. For 55% of the Chinese microbloggers on Sina Weibo, we did not observe any hashtag. In contrast, on Twitter the people make more frequently use of hashtags or URLs. For example, for more than 85% of the Twitter users, the average number of hashtags per post is at least 0. 1, i.e. at least every tenth micropost mentions a hashtag, and 3.9% of the users mention, on average, even more than one hashtag per tweet In Table 3 we analyze the influence of the access behavior(see Sect. 4.1)on the usage of hashtags and URLs. For both services, we observe that the usage of hashtags and URLs decreases slightly when people publish microposts from their mobile devices instead of their desktop computers. This difference is more significant on Sina Weibo. For example, on Sina Weibo the number of posts that contain a URL and are issued from a desktop application(17. 8%)is mor than three times higher than the one for mobile devices(.2%). On Twitter, the usage of URLs on desktop devices is only 1.57 times higher than on mobile devices. Regarding the type of activity that a user performed to publish a mi- cropost, we observe that 97.9% of the tweets that were generated as byproducts of other activities (e.g. publishing an article in a blog or check-in"activities on Foursquare)contain URLs. In contrast, for the conventional microblogging, only 25. 3% of the Twitter messages contain URLs. A similar increase can be6 Qi Gao, Fabian Abel, Geert-Jan Houben, Yong Yu syntactic characteristics proportion of posts posts that contain: Weibo Twitter hashtags 6.3% 20.0% URLs 14.8% 29.1% question marks “?” 9.9% 18.6% exclamation marks “!” 26.1% 20.7% “?” and “!” 3.1% 3.5% Table 2. Comparison of syntactic content analysis 0% 20% 40% 60% 80% 100% users 0 0.01 0.1 1 avg. number of hashtags/URLs per post Hashtag-Weibo URL-Weibo Hashtag-Twitter URL-Twitter Fig. 2. Comparison of writing style for in￾dividual users – F2: The results regarding the individual users’ access behavior illustrate that Twitter users switch between different clients more often than the users on Sina Weibo. This difference in behavior could be explained by the lower overall number of valuable Sina Weibo client applications (e.g. in our dataset: 3015 different Sina Weibo clients versus 5468 Twitter clients). 4.2 Syntactic Content Analysis Results In Table 2, we compare the syntax of messages posted on Sina Weibo and Twitter and particularly the usage of hashtags and URLs. Overall, 20% of the Twitter messages contain hashtags and 29.1% of the tweets feature a URL. Therefore, the usage of hashtags and URLs on Twitter is 3.2 times and 1.97 times respectively more intensive than on Sina Weibo. The analysis of special charac￾ters implies that users on Twitter ask more than twice as many questions than users on Sina Weibo (see question marks in Table 2). In contrast, Sina Weibo users make more extensive use of exclamation marks and therefore more often put extra emphasis on their statements. To further analyze the usage of hashtags and URLs, we also plot for each individual user in our samples the average number of hashtags and URLs per post. From Fig. 2, we infer that a considerably high fraction of Sina Weibo users does not mention hashtags or URLs at all. For 55% of the Chinese microbloggers on Sina Weibo, we did not observe any hashtag. In contrast, on Twitter the people make more frequently use of hashtags or URLs. For example, for more than 85% of the Twitter users, the average number of hashtags per post is at least 0.1, i.e. at least every tenth micropost mentions a hashtag, and 3.9% of the users mention, on average, even more than one hashtag per tweet. In Table 3 we analyze the influence of the access behavior (see Sect. 4.1) on the usage of hashtags and URLs. For both services, we observe that the usage of hashtags and URLs decreases slightly when people publish microposts from their mobile devices instead of their desktop computers. This difference is more significant on Sina Weibo. For example, on Sina Weibo the number of posts that contain a URL and are issued from a desktop application (17.8%) is more than three times higher than the one for mobile devices (5.2%). On Twitter, the usage of URLs on desktop devices is only 1.57 times higher than on mobile devices. Regarding the type of activity that a user performed to publish a mi￾cropost, we observe that 97.9% of the tweets that were generated as byproducts of other activities (e.g. publishing an article in a blog or “check-in” activities on Foursquare) contain URLs. In contrast, for the conventional microblogging, only 25.3% of the Twitter messages contain URLs. A similar increase can be