Items each represented 16 different Vesatolimod supplier topics that received high engagement in just one platform (hereafter: “unique” Anlotinib web high-engagement items). These data indicate an association between high engagement and item topic (2(47) = 80.054, n = 214, p < 0.01, Cramer's V = 0.612).PLOS ONE | DOI:10.1371/journal.pone.0156409 May 27,13 /Engagement with Particle Physics on CERN's Social Media PlatformsTable 8. Recurring high engagement topics. Recurring High Engagement Topic Code 1. 2. 3. 4. 5. 6. Fabiola Open Data Pipes 1st Computer CMS Dishwasher Type News News Guess What It Is Throwback Thursday Wow Wow Image Caption "CERN Council selects Italian physicist, Dr Fabiola Gianotti, as CERN's next Director-General" "CERN launches Open Data Portal to make public the data of LHC experiments" "CERN's cooling ventilation systems get refreshed" "The Ferranti Mercury, CERN's 1st 'central' computer" "The LHC's Compact Muon Solenoid (CMS) detector" "That's right, a CERN dishwasher for circuit boards" Recurred as High Engagement Item on. . . Facebook, Twitter English, Twitter French Facebook, Google+, Twitter English, Twitter French Google+, Twitter French Facebook, Twitter English Instagram, Twitter English, Twitter French Facebook, Google+, Instagram, Twitter English, Twitter Frenchdoi:10.1371/journal.pone.0156409.tSome characteristics of the high-engagement topics are that they may have referred to (1) news items receiving attention from traditional media (e.g. the "Fabiola" topic), or (2) a surprising or awe-inspiring image (e.g. "CMS", "Dishwasher" and "Pipes") (Table 8).Research LimitationsThe main methodological limitation in this study stems from the architecture of the platforms. The items posted were not necessarily seen by all CERN's subscribers. The "organic reach" is determined by the technical settings of the platforms, and may be affected by many different variables. For example, one study found that organic reach increases on a given Facebook item if another item was posted on the platform the day before [30]. The results are based on data collected from October to December 2014, however changes may have occurred since then at multiple levels: from the CERN social media strategy and behaviour, to the architecture of the platforms, as well as the audiences, their preferences and the general online communication landscape. Concerning CERN's strategy and posting behaviour, this has remained consistent with the data-taking period. However, platform architectures are regularly changed and updated. Since our findings indicate that the platform itself influences user behaviour, it follows that changes in the platform may have an effect. For example, Twitter has implemented a new feed algorithm [43]. Google+ has been fully redesigned [44]. Facebook have not only changed the way that content from pages are delivered to the audience [45], they are also placing more and more emphasis on video content, particularly live or immersive videos, over other types of content [46]. One recent Facebook update now allows people to express their feelings as "reactions" to the information published [47]. These changes call for more elaborate future research in this topic, with fine-tuned analysis that looks at both the comments and the reaction icons. The online communication landscape in general has become more mobile, with some audiences shifting to other social media platforms such as Snapchat. Notwithstanding the dynamics of this field, our systematic study still.Items each represented 16 different topics that received high engagement in just one platform (hereafter: "unique" high-engagement items). These data indicate an association between high engagement and item topic (2(47) = 80.054, n = 214, p < 0.01, Cramer's V = 0.612).PLOS ONE | DOI:10.1371/journal.pone.0156409 May 27,13 /Engagement with Particle Physics on CERN's Social Media PlatformsTable 8. Recurring high engagement topics. Recurring High Engagement Topic Code 1. 2. 3. 4. 5. 6. Fabiola Open Data Pipes 1st Computer CMS Dishwasher Type News News Guess What It Is Throwback Thursday Wow Wow Image Caption "CERN Council selects Italian physicist, Dr Fabiola Gianotti, as CERN's next Director-General" "CERN launches Open Data Portal to make public the data of LHC experiments" "CERN's cooling ventilation systems get refreshed" "The Ferranti Mercury, CERN's 1st 'central' computer" "The LHC's Compact Muon Solenoid (CMS) detector" "That's right, a CERN dishwasher for circuit boards" Recurred as High Engagement Item on. . . Facebook, Twitter English, Twitter French Facebook, Google+, Twitter English, Twitter French Google+, Twitter French Facebook, Twitter English Instagram, Twitter English, Twitter French Facebook, Google+, Instagram, Twitter English, Twitter Frenchdoi:10.1371/journal.pone.0156409.tSome characteristics of the high-engagement topics are that they may have referred to (1) news items receiving attention from traditional media (e.g. the "Fabiola" topic), or (2) a surprising or awe-inspiring image (e.g. "CMS", "Dishwasher" and "Pipes") (Table 8).Research LimitationsThe main methodological limitation in this study stems from the architecture of the platforms. The items posted were not necessarily seen by all CERN's subscribers. The "organic reach" is determined by the technical settings of the platforms, and may be affected by many different variables. For example, one study found that organic reach increases on a given Facebook item if another item was posted on the platform the day before [30]. The results are based on data collected from October to December 2014, however changes may have occurred since then at multiple levels: from the CERN social media strategy and behaviour, to the architecture of the platforms, as well as the audiences, their preferences and the general online communication landscape. Concerning CERN's strategy and posting behaviour, this has remained consistent with the data-taking period. However, platform architectures are regularly changed and updated. Since our findings indicate that the platform itself influences user behaviour, it follows that changes in the platform may have an effect. For example, Twitter has implemented a new feed algorithm [43]. Google+ has been fully redesigned [44]. Facebook have not only changed the way that content from pages are delivered to the audience [45], they are also placing more and more emphasis on video content, particularly live or immersive videos, over other types of content [46]. One recent Facebook update now allows people to express their feelings as "reactions" to the information published [47]. These changes call for more elaborate future research in this topic, with fine-tuned analysis that looks at both the comments and the reaction icons. The online communication landscape in general has become more mobile, with some audiences shifting to other social media platforms such as Snapchat. Notwithstanding the dynamics of this field, our systematic study still.