Millions of people see science-related information on their Facebook feeds or elsewhere on social media, but the kinds of science stories people most likely encounter are often practical tips with “news you can use” or promotions for programs and events rather than new developments in the science, engineering and technology world.

In an effort to better understand the science information that social media users encounter on these platforms, Pew Research Center systematically analyzed six months’ worth of posts from 30 of the most followed science-related pages on Facebook. These science-related pages included 15 popular Facebook accounts from established “multiplatform” organizations – for example National Geographic and the Discovery Channel – along with 15 popular “Facebook-primary” accounts from individuals or organizations that have a large social media presence on the platform but are not connected to any offline, legacy outlet.

Some of the key findings from this analysis:

Millions of people follow science-related pages on Facebook. Multiplatform organizations have taken advantage of Facebook’s capacity to reach large numbers of followers on a new platform. For instance, as of June 2017, National Geographic had 44.3 million Facebook followers, Discovery had 39 million and Animal Planet had 20 million. (See the Appendix for more details about the nature of these pages.)¹

At the same time, “Facebook-primary” pages have arisen in a relatively short time and built impressive audiences. This illustrates the degree to which social media have transformed the media landscape, making it easier and cheaper for those with few resources to provide unmediated content and garner followings. For example, a single enterprising writer built the Facebook page IFLScience in 2012, which has grown to 25.6 million followers and a staff of approximately 15. Social media have also provided a platform for prominent science figures such as Stephen Hawking² (followed by 3.9 million users on Facebook as of June 2017), Bill Nye (followed by 4.8 million) and Neil deGrasse Tyson (followed by 4 million).

New scientific discoveries are covered in 29% of the posts on these pages. Each of these 30 science-related pages has its own distinctive flavor. Still, a few common themes emerged from a detailed content analysis of a random sample of 6,582 posts published in the first half of 2017.

While these 30 Facebook pages with a self-described focus on a science-related area cover a range of topics, just 29% of the Facebook posts from these pages had a focus or “frame” around information about new scientific discoveries. Some pages used a new-discovery frame in the bulk of their posts. For example, that was true of ScienceAlert, IFLScience, NASA Earth and New Scientist. But that framing was rare on other pages. Across the 30 pages, other frames were evident when researchers coded a representative sample of the posts. Fully 21% of posts featured the practical applications of science information, relying on a “news you can use” frame. Another 16% of posts were promotions or advertisements for media or events, 12% of posts were aimed at explaining a science-related concept, and the remainder used some other frame.

The volume of posts from these science-related pages has increased over the past few years, especially among multiplatform pages. On average, the 15 popular multiplatform Facebook pages have increased their production of posts by 115% since 2014, compared with a 66% increase among Facebook-primary pages over the same time period.

The average number of user interactions per post – a common indicator of audience engagement based on the total number of shares, comments, and likes or other reactions – tends to be higher for posts from Facebook-primary accounts than posts from multiplatform accounts. From January 2014 to June 2017, Facebook-primary pages averaged 14,730 interactions per post, compared with 4,265 for posts on multiplatform pages. This relationship held up even when controlling for the frame of the post.

Higher engagement is seen on posts focused on visuals with little additional information. Other posts with relatively high engagement include calls to action and posts dealing with science funding. Analysis of the types of posts yielding the highest average of interactions shows that visual posts with little or no text tend to yield more audience engagement than most other frames. Additionally, posts with an explicit call to action produce high numbers of interactions. However, such posts are quite rare, comprising just 2% of all posts across the 30 pages. And, posts on Facebook-primary pages related to federal funding for agencies with a significant scientific research mission were particularly engaging, averaging more than 122,000 interactions per post in the first half of 2017.

The most-engaging posts from either Facebook-primary or multiplatform pages during this period included a wide range of topics and frames. Video was a common feature of these highly engaging posts whether they were aimed at explaining a scientific concept, highlighting new discoveries, or showcasing ways people can put science information to use in their lives.

Highly engaging posts among these pages did not always feature science-related information. Four of the top 15 most-engaging posts from Facebook-primary pages featured inspirational sayings or advice such as “look after your friends” or “believe in yourself.” And, the single most-engaging post among the multiplatform pages was an expression of support for those in Paris after a terrorist attack.

There is considerable variation in what topics these popular Facebook science-related pages focus on. Most pages in this sample specialized on posts connected with just one or two science topics. For example, pages such as Daily Health Tips and Health Digest focused a majority of their content on health and medicine topics, while NASA for the most part posted content related to astronomy and physics. Only four of the 30 pages covered a roughly even mix of posts on several topics, with no single topic making up more than one-in-five posts on the account.

These findings emerge as more and more material on all kinds of subjects is posted and disseminated on social media. A 2017 Pew Research Center survey found most social media users in the U.S. report seeing science-related posts and a third (33%) consider it an important way they get science news. Some 44% of social media users say they see content unique to that platform at least sometimes, and 26% of users report that they follow a science-related page or account. Other Pew Research Center surveys show that Facebook is used by a far larger share than other social media platforms.

It is important to note that for the purposes of this analysis the selection of “science-related” pages was based on each page’s self-statement that it covers content about science or about a major area connected with science, technology, engineering or math. (Pages focused primarily on commercial or advocacy missions were excluded.) The set of 30 covers a broad range of pages available to social media users, including several that are widely seen in the scientific community as offering questionable or even “pseudoscientific” advice or information.

As concerns about public understanding and acceptance of scientific evidence have increased over the past few years, this analysis provides a window into the sources of information that – while may differ from consensus views in the scientific community – have, nonetheless, attracted millions of followers and more who see posts from these pages in their Facebook news feed even without following the page. As such, these data help better understand the sources of information that may influence public views and understanding of science-related issues.

Science-related Facebook pages are posting more often, especially multiplatform pages

In just a few years, the volume of posts produced by this set of science-related pages has grown dramatically, particularly among multiplatform pages. The 15 multiplatform pages doubled their production of posts from roughly 37,000 in 2014 to an estimated 79,000 in 2017 (a 115% increase), though much of the uptick in volume of posts from multiplatform pages stems from just a few accounts.³ The 15 Facebook-primary pages also increased their total number of posts from roughly 31,000 in 2014 to an estimated 52,000 in 2017 (a 66% increase).⁴

The total volume and frequency of posts from each of these 30 accounts varies widely, however. The number of posts from 2017 is estimated from doubling the number posted during the first half of the year due to missing data in Facebook’s API for the second half of the year.

The 2017 annual volume of posts across the 15 Facebook-primary pages ranged from about 24 posts by Stephen Hawking to more than 10,000 posts from mindbodygreen, a health and wellness media company. Four of these accounts – all of which are associated with prominent scientific figures – have more than 3 million followers but posted no more than about 200 times in 2017. Among the other pages, most increased the volume of posts over this time period. See Appendix table for details.

Some science-related accounts use Facebook differently than Twitter

The profile of these science-related accounts can vary across other social media platforms. To illustrate, Pew Research Center looked at Twitter activity from the same 30 organizations as of January 2018.

While far more adults in the U.S. use Facebook (68%) than Twitter (21%), according to a 2018 Pew Research Center survey, a handful of science-related pages in this study were comparatively more active on Twitter.

Neil deGrasse Tyson had about 11.4 million Twitter followers as of January 2018, roughly 2.5 times more than his 4 million Facebook followers. He was more active tweeting (493 times in 2017) than he was posting content on Facebook (about 130 times in 2017).

Similarly, Bill Nye was more active on Twitter than on Facebook (253 tweets in 2017, compared with about 84 posts).

Among the multiplatform pages, NASA and Popular Science were about twice as active tweeting than posting Facebook content in 2017. But while NASA had many more followers on Twitter than on Facebook (28.2 million vs. 19.4 million), Popular Science had a smaller user base on Twitter (1.3 million vs. 3.5 million on Facebook).

But several of these pages were less active on Twitter, particularly among the Facebook-primary pages. The list includes Health Digest, David Wolfe, ScienceDump, Hashem Al-Ghaili and Smart is the New Sexy, all of which have had a far less active presence on Twitter than Facebook and had orders of magnitude fewer followers on Twitter.⁵ Stephen Hawking did not have an official Twitter account; Hashem Al-Ghaili and ScienceDump barely had a presence on Twitter, each with fewer than 5 posts in 2017.

All of the 15 multiplatform pages had a presence on Twitter. Only one in this set tweeted less than 1,000 times in 2017: MythBusters, a page that also posted on Facebook fewer than 500 times in 2017. Some multiplatform pages were less active on Twitter than they were on Facebook, including Animal Planet, BBC Earth and Physics Today.

At a time when science issues are increasingly part of the broader public discourse, Pew Research Center explored the role of science-related Facebook pages – both those that were meant to enhance the reach of existing science-related media enterprises and those that arose from science enthusiasts and experts utilizing social media platforms to bring their voice to science issues.

The analysis shows that users encounter a wide range of content on science-related Facebook pages. Few of the 30 pages in this analysis produce content across a range of STEM-related areas; in fact, just four of the 30 produce roughly similar shares of posts on several topics. Instead, most pages specialize. The bulk of their content touches just one or two science topics, such as health and medicine, food and nutrition, animal science, or astronomy and physics.

Further, each page tends to present content from one of a handful of frames, and for nearly two-thirds of the pages in this set, a majority of posts reflect just one frame: either new science-related discoveries, science news you can use, or promotions for programs or events.

A systematic analysis of posts produced by these 30 pages over the first half of 2017 found more variation among the pages than there was commonality. Most of these 30 pages appear to feature content they produce themselves, though a few of the Facebook-primary pages appear to serve primarily as aggregators with virtually no content originating from the source organization for the page.

Most science-related Facebook pages focus their content on one or two subject areas, especially health and food topics

Across this set of 30 pages, few aim to cover science across a range of scientific domains. Instead, most pages ­ whether Facebook-primary or multiplatform ones ­ specialize in one or two science topic areas. For example, 70% of posts from Interesting Engineering were related to engineering and technology topics. Similarly, 73% of posts from Psychology Today were related to the behavioral sciences, and nearly three-quarters of posts from NASA Earth (73%) were about energy and the environment.

Only four of the pages covered a roughly even share of posts on several topics, with no single topic making up more than one-in-five posts. These were IFLScience, ScienceAlert and ScienceDump, among the Facebook-primary pages, and New Scientist, among the multiplatform pages.

Health and medicine was the predominant topic in posts from many of these pages. About half or more of the posts from three of the Facebook-primary pages and two of the multiplatform pages were about health or medicine topics. For example, health/medicine topics were featured in 65% of posts from Daily Health Tips, 59% of Health Digest posts, and about half of the posts from Women’s Health, Health, and Dr. Oz (a cardiothoracic surgeon known for his appearances on television).⁶

Pages featuring a sizeable share of posts on health and medicine also tend to include posts on food, nutrition and the health effects of foods. Together, the share of posts on either health/medicine or food/nutrition account for the vast majority of posts from Daily Health Tips (92%), Health Digest (89%), Health and Dr. Oz (79% each). They also account for six-in-ten posts from Women’s Health Magazine (60%).

Looking across all of these pages, 39% of posts from Facebook-primary pages and 15% of posts from multiplatform posts related to health and food topics. Among this group, many featured posts on personal health, nutrition, weight loss, exercise and beauty tips, such as a post suggesting that consuming garlic will help lower blood sugar and cholesterol levels (as seen in a June 16, 2017, Daily Health Tips post) and another extolling the virtues of egg and olive oil for healthy hair (also seen in another post from Daily Health Tips on June 16, 2017).

Animal science was the leading topic on three of the multiplatform pages. Posts about animals made up at least half of the content from Animal Planet (75%), BBC Earth (56%) and National Geographic (50%). None of the 15 Facebook-primary pages featured a large share of posts about animals; the largest in this set was IFLScience with 18% of its posts related to animal science.

Three of the Facebook-primary pages belong to prominent astrophysicists. Not surprisingly, about half or more of the posts on these pages were related to astronomy or physics: Dr. Michio Kaku (58%), Stephen Hawking (58%) and Neil deGrasse Tyson (48%).

Bill Nye, another prominent figure known primarily as a science educator, tended to post more generic content; 67% of the posts from his page were categorized as general and not connected with a specific science topic. Many of these posts offered previews of his book and his Netflix television program. (For more on promotional posts, see the discussion below on the primary “frame” of posts on these pages.)

Some pages included a sizeable share of posts that were far afield from science topics. For example, about a third of the posts on Smart is the New Sexy (32%) and almost three-in-ten posts on David Wolfe’s page (28%) were not about science topics. Many of these posts featured inspirational quotes, holiday greetings, news about popular culture or demonstrations showing how to make crafts.

Science-related stories at the center of public divisions did not appear often on these Facebook pages

Coverage of major scientific controversies in public discourse was rare on these Facebook pages. For example, while an average of 8% of posts across the 30 pages were about energy and environmental issues, broadly speaking, a much smaller share of these posts were related to climate change – only 1% of posts on Facebook-primary pages and 2% on multiplatform pages.⁷

Similarly, only about 1% of posts mentioned genetically modified foods or crops.

The April 22, 2017, March for Science, which included a large demonstration in Washington, D.C. and hundreds of satellite protests, marches and demonstrations around the world, received hardly any attention on these pages, accounting for less than 1% of all posts. There were just five posts in the entire sample of 30 Facebook pages that mentioned the March for Science during the month of April in 2017; three of these were from Bill Nye, an honorary co-chair for the event.

Multiplatform pages rely heavily on their own content sources; a few Facebook-primary pages serve as aggregators, mostly sharing content published by other organizations

An ongoing question about news shared on social media platforms concerns the extent to which the accounts are featuring information they produce themselves or whether they amplify information produced by other organizations, perhaps with the assistance of automated news generators.

One way to gauge the extent to which these pages are generating custom content for their pages is to classify the source of each post as stemming from the account holder or from an outside organization.⁸

Multiplatform pages tend to have staff and other resources that might make it easier to create custom-generated content on their pages. The majority of posts from the 15 multiplatform pages came from content produced by the page owner’s organization. Indeed, 100% of the posts on the National Geographic and Science Magazine Facebook pages were produced by their own organizations. The vast majority of posts from a number of other science-related pages for multiplatform organizations also followed this strategy.

There was more variation among the set of Facebook-primary pages. While a page such as IFLScience started with just one person in 2012, it has grown in staff and resources. Some 93% of the posts from IFLScience during the time studied came from content produced by that organization, as did 95% of the posts from Interesting Engineering and 100% of the posts from mindbodygreen.

ScienceDump and a few of the other Facebook-primary pages, on the other hand, appear to serve primarily as web aggregators, linking to content originally produced by others. Daily Health Tips appears to serve almost exclusively as an aggregator, producing virtually no original content.⁹

Most science Facebook pages have a single frame for their stories

Pew Research Center coded the primary “frame” (or main goal or focus of the post) of a random sample of posts from each page appearing in the first half of 2017. The bulk of posts across the 30 Facebook pages utilized one of three frames: news about a scientific discovery or development, science-related “news you can use,” or a promotion for a media program on another platform.

Scientific discoveries

Overall, 29% of the posts across these 30 pages featured a new scientific discovery or development. The bulk of posts from ScienceAlert (72%), NASA Earth (71%), New Scientist (69%) IFLScience (68%) and Science magazine (61%) were aimed, primarily, at sharing news about a recent science discovery or development. Examples include a March 20, 2017, post from NASA showing years of satellite images demonstrating that New Zealand’s glaciers are retreating; a post from Science magazine on March 7, 2017, about new developments in the study of neural networks; and a May 5, 2017, post from New Scientist about researchers who recreated a gene from billions of years ago that help explains how early life coped with oxygen-poor air.

Across the 30 Facebook pages, a majority of these posts focused on energy and environment, geology, and archeology, and about half of posts on astronomy or physics had a new discovery frame.

‘News you can use’

The next most common type of post – comprising 21% of posts across these 30 pages in this sample – showed science “news you can use,” much of which was advice-oriented and self-help tips. A majority of posts from three Facebook-primary accounts with a large share of posts on health/medicine and food/nutrition had a “news you can use” frame: Daily Health Tips (96%); Health Digest (85%); mindbodygreen (69%). And two of the multiplatform pages used a “news you can use” frame in the majority of their posts: Psychology Today (67%) and Health (56%). Across the 30 pages, 67% of posts related to food and nutrition used a “news you can use” frame, as did 56% of posts on behavioral science and 48% of posts focused on health and medicine.

Promotional posts

Across the set of 30 pages, 16% of posts were promotional in nature. Several accounts aimed a majority of their posts at promoting other media and public appearances. The four prominent scientists among the Facebook-primary pages posted fewer than 200 times over the course of 2017, but when they did, a majority of their posts were promotions (79% of posts from Dr. Michio Kaku, 78% of posts from Neil deGrasse Tyson, 64% of posts from Bill Nye and 58% of posts from Stephen Hawking). Most of these were self-promotional posts related to television appearances, book signings or speeches.

About half or more of the posts from three multiplatform pages were focused on promotions: Animal Planet (79%), Discovery (65%) and MythBusters (54%). Promotional posts on Discovery were mostly promoting shows from Discovery Communication Inc.; promotional posts on the MythBusters page generally promoted episodes from the show, another of the Discovery Communications Inc. productions.

Beyond these three frames, other focus points for the Facebook posts were less common. Across the 30 pages, some 12% of posts focused on explanations of a scientific concept or idea. A handful of pages (such as Hashem Al-Ghaili’s Science Nature Page, Interesting Engineering, National Geographic and Science Channel) included a sizeable share – around a fifth to a quarter – of posts that focused on explanations of a scientific concept or idea. Examples of these include a post on Interesting Engineering about the design of a suspension bridge in Bristol, England, and a video posted on Science Channel’s page demonstrating the size of the world’s largest radio telescope located in China.

No other frame accounted for more than 10% of Facebook posts across the 30 pages. A few pages included archived or previously published material in about 20% to 30% of their posts (e.g., Women’s Health, Popular Science, Smart is the New Sexy, and David Wolfe). And one page, Physics Today, included about three-in-ten posts that profiled notable scientists.¹⁰ See Appendix for details.

Multiplatform pages link to external research sources slightly more often than Facebook-primary pages

To gauge the extent to which these Facebook pages spread information about scientific research, Pew Research Center analysis classified the share of posts that included a link to research evidence from an outside organization.

In total, the study found that nearly one-quarter of posts on these 30 pages (23%) linked to external scientific research.¹¹ Such links were often to peer-reviewed publications, but some were original research from government agencies or other institutions.¹² On average, links to external scientific research were more common among multiplatform pages (25%) than among Facebook-primary pages (21%).

The share of posts with links to outside research varies widely depending on the frame of the post. Among the small number of posts related to conflict or disagreement about scientific findings appearing on any of these 30 pages, 64% had an external link.

Of posts across these 30 pages using a new scientific discovery frame, 47% included a link or reference to outside evidence (50% among Facebook-primary and 44% among multiplatform pages). A majority of posts from ScienceAlert, for example, featured a new scientific discovery or development, and the vast majority of those posts included a link to outside evidence.

A minority of posts using a “news you can use,” promotion, or explanation frame included links to external evidence.

While the most common frames for posts on the 30 science-related Facebook pages in this analysis feature new discoveries or science “news you can use,” posts with more engagement – a term used to characterize the number of user interactions with a post from shares, comments, and likes or other reactions – tend to use other frames. Posts from the first half of 2017 with the highest average number of interactions per post used frames related to science research funding and pictures or other visual display with little or no text.

Posts related to science funding were typically tied to discussion of President Donald Trump’s first proposed budget in early 2017 and the potential changes for science funding. Those were topics of unique prominence during the study period, January to June 2017. Only 1% of posts in the sample from these 30 pages used a frame centered on science research funding. Audience interaction with such posts was high, however, particularly on Facebook-primary pages.

Posts on the 15 Facebook-primary pages with a research-funding frame averaged 122,126 interactions each, more than three times the next highest category. By contrast, posts using a research-funding frame on the 15 multiplatform pages averaged just 1,539 interactions per post.

Many of these highly engaging posts linked to stories suggesting Trump was considering a decrease in science-agency funding. For example, a Jan. 25, 2017, IFLScience post called Trump’s Freeze On EPA Grants Leaves Scientists Wondering What It Means was shared more than 22,000 times on Facebook and had 62,000 likes and other reactions.

Beyond posts with a research funding frame, those consisting solely of a visual display (using little or no text) and those with a call to action were also highly engaging. Visual posts could cover a range of topics; some used videos with almost no text while others were picture-based. Call to action posts include those that explicitly requested that users engage with the post, such as asking users to provide a caption for a photo or share the post with others.

Both types of posts are relatively uncommon, each consisting of only 2% to 3% of posts across the 30 science-related pages. Here, too, however, posts with these frames from the Facebook-primary pages averaged more interactions than those with the same frame from the multiplatform pages. On Facebook-primary pages, visual posts averaged nearly 37,000 interactions each. On multiplatform pages, these types of posts averaged about half as many interactions, roughly 18,500 interactions each.

Overall, posts from the 15 Facebook-primary pages averaged a higher number of interactions than posts using the same frame among the 15 multiplatform pages. Two exceptions were posts using a travel frame and those related to media coverage of science. For these frames, audience engagement was higher, on average, for posts from the multiplatform pages. Travel posts were more common on the National Geographic and Discovery pages; many of these posts included photographs of scenic destinations such as Vancouver and the cliffs of Ireland.¹³

The reasons behind the generally higher interactions with posts on the Facebook-primary as compared with the multiplatform pages are not clear. There may be systematic differences in the way these pages use each frame, which impacts audience engagement. Exploration of such differences goes beyond the aspects examined in the current study.

Facebook pages with more followers likely yield more interactions in large part because more users generally see posts from those pages in their news feeds. However, users who do not follow a given page may also encounter the same content. Any time a user interacts with a post, that post may appear in the news feed of their friends, even of those who do not follow the page.

Facebook uses proprietary algorithms to determine which posts show up in a user’s news feed. Facebook has made numerous changes to its algorithms over the years, and these changes affect the level of engagement posts receive. It is hard to evaluate the impact of changes in the algorithms because Facebook does not disclose the full details of the proprietary algorithms that drive the content users see. This study was conducted in 2017, prior to a major 2018 announcement by Facebook’s CEO Mark Zuckerberg of further changes to its algorithms, giving more weight to content from friends and family over that of news organizations and other content providers that are not individuals.

Other framing categories

Posts categorized as topically unrelated to a scientific domain were listed in this study as using a non-science frame. As with most other types of frames, non-science posts across the set of 15 Facebook-primary pages averaged higher levels of audience engagement than did those using the same frame from multiplatform pages. For Facebook-primary pages, these posts received an average of about 14,500 interactions each – putting the category in the middle-of-the-pack compared with other frames. For multiplatform pages, however, non-science posts averaged less than 900 interactions each, lower than for any other frame used. These types of posts made up 8% of posts on Facebook-primary pages, compared with just 2% of multiplatform pages. One example of a highly engaging post of this sort featured an inspirational quote; this post from David Wolfe’s page on Nov. 27, 2015, was shared more than 1.3 million times and received more than 29,000 comments. As shown in a nearby table, this post was one of the top 15 most-engaging posts across any of the 15 Facebook-primary pages between January 2014 and June 2017.

As discussed in Chapter 1, these 30 Facebook pages tend to focus on just one or two scientific topics or domains. The average interaction with posts was not strongly correlated with the topic area of the post. See Appendix for details.

The most popular individual posts on these science-related pages used a variety of frames, and many included video and were produced by just a few Facebook accounts

A close examination of the top 15 most engaging individual posts from this set of 30 science-related Facebook pages in the last few years (Jan. 1, 2014 to June 30, 2017) finds that these posts represent a variety of science topics and frames. While the average interactions for posts using a visual-only frame and call-to-action frame tend to be higher than posts with other frames, there are posts in the top 15 with the most engagement from a wide range of frame types, including posts that explain scientific concepts, highlight new discoveries and feature ways people can put science information to use in their lives.

Video is a common feature among many of these Facebook posts with the highest levels of user engagement. Among posts appearing on the multiplatform pages between January 2014 and the end of June 2017, 12 of the top 15 most-engaging posts included video. Six of top 15 posts appearing on the Facebook-primary pages during this period also included video, while another 6 from this set of pages included a prominent picture.

National Geographic produced the greatest share of the top 15 most-engaging posts among the multiplatform pages (11 of the 15). Most of these included videos of animals such as a Sept. 8, 2016, video of Alpine goats climbing a mountain.

The single post with the highest number of interactions for multiplatform pages during this time period was picture of the Eiffel Tower posted on Nov. 14, 2015, in response to terror attacks in Paris. This post from National Geographic on a non-science topic included the hashtag #lovetoParis and had more than 1.1 million likes and other reactions, 182,000 shares and 9,600 comments.

Among the science-related Facebook-primary pages, 12 of the top 15 most engaging posts were produced by David Wolfe, an author and product spokesman who emphasizes alternative remedies and promotes the health benefits of raw foods.¹⁴ Half of these 12 popular posts from David Wolfe featured inspirational sayings or advice, such as an April 2015 post which encouraged readers to “look after your friends.”

The single post with the most interactions (5.4 million in total) was a call for participation. The post – produced by David Wolfe on Oct. 10, 2015 – featured a picture of fruit cups and a request that users should “share this if you think they should have this in school.”

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This report is made possible by The Pew Charitable Trusts. This report is a collaborative effort based on the input and analysis of the following individuals. Find related reports online at: pewresearch.org/pewresearch-org/science.

Primary research team

Paul Hitlin, Senior Researcher Kenneth Olmstead, Research Associate Cary Funk, Director, Science and Society Research

Collaborating research team

Lee Rainie, Director, Internet and Technology Research Aaron Smith, Associate Director, Research Skye Toor, Data Science Assistant Andrew Perrin, Research Analyst Veronica Garcia, Coder Jack Marshall, Coder

Editorial and graphic design

Shannon Greenwood, Copy Editor Margaret Porteus, Information Graphics Designer

Communications and web publishing

Tom Caiazza, Communications Manager Shannon Greenwood, Associate Digital Producer  

Data in this study came from two main data sources: 1) analysis of Facebook posts from a set of 30 science-related pages based on data downloaded from the public Facebook Graph API from Jan. 1, 2014 to June 30, 2017, and 2) human content analysis coding by Pew Research Center staff of a random selection of Facebook posts produced by each of these pages from Jan. 1 to June 30, 2017.

Selection of science-related Facebook pages

For a comparison of Facebook pages from Facebook-primary and multiplatform organizations, the Center identified science-related public pages (in English only) with a large number of followers.  The term “follower” is used interchangeably throughout this report with the number of users who “like” a page using the thumbs up icon.

The selection of “science-related” pages was based on each page’s self-statement that it covers content about science or any of the following science topics: health/medicine, food/nutrition, astronomy, physics, biology/animal science, neurology, chemistry, technology/engineering, energy/environment, geosciences, math, or social and behavioral sciences. The categories broadly align with the major fields of scientific inquiry as defined by the National Science Foundation.

Commercial pages aimed primarily at selling consumer products were excluded, as were advocacy pages such as The Breast Cancer Site and PETA. Pages that covered a range of health/medicine topics were eligible for selection but those that focused exclusively on exercise or recipes were not.

There is no definitive list of science-related Facebook pages. (Facebook offers a list of science pages on its site, but the list is not exhaustive.) To create the list of popular pages analyzed in this study, five researchers searched for pages with a large number of page likes using a variety of methods in June 2017. Using Facebook’s search function, numerous blogs and articles, and results from searches on sites such as Google and trackalytics.com, the Center compiled a list of more than 200 English-language science-related pages that met the above criteria. Only pages with at least 2 million page likes were recorded since pages with fewer followers would not have enough to qualify among the top 30 pages. Each page was classified into one of two groups: a Facebook-primary page or a multiplatform page. The top 15 most popular pages from each group were selected for this study.

A page was considered a Facebook-primary page if it was run by an individual or an organization that used Facebook as their primary way of disseminating information. In some cases, such as IFLScience and ScienceAlert, Facebook was central to the creation and growth of their content and audience. In other cases, such as Stephen Hawking, Bill Nye or Neil deGrasse Tyson, prominent scientists were public figures prior to the creation of Facebook, yet the social media site has enabled these people to reach larger audiences.

Multiplatform pages were run by organizations whose primary method of communication was a media outlet that existed prior to the growth of Facebook as a social media platform. National Geographic, for example, has had a popular magazine and television channel for years. Women’s Health and Popular Science are best known for their traditional magazines rather than their social media presence. The pages for NASA and NASA Earth represent a government agency that has existed for decades.

Content Analysis of Facebook pages

Historical data from Facebook Graph API

Pew Research Center downloaded the details for all posts from the selected pages from Jan. 1, 2014, to June 30, 2017, from version 2.8 of the Facebook Graph API. Using Python scripts, details were collected regarding each post’s creation date, ID, description, caption, link, permalink and the total number of shares, comments, likes and other reactions. In total, details were collected for 340,333 posts from the 30 Facebook pages.

For posts created from January 2014 to March 2017, the details were downloaded from the API during the months of April and May 2017. For posts created from April to June 2017, the details were downloaded during July 2017. Because the numbers of comments, shares, and likes and other reactions can increase over time, the numbers included in this study reflect the numbers at the time of capture.

Data from the following dates/pages were not available from the Facebook API: Interesting Engineering from Jan. 1-April 13, 2014; Dr. Mehmet Oz from Jan. 1-April 29, 2014; Science Channel from Jan. 1-Sept. 19, 2015; and BBC Earth from Jan. 31-March 27, 2014.

Posts for the page Daily Health Tips were missing from the Facebook API for Jan. 7-April 11, 2017. However, researchers were able to manually capture the ID for each of those missing posts and consequently download the accompanying details of all posts during that time. Therefore, those Daily Health Tips posts are included in the study.

Facebook’s API is missing data for large numbers of posts in the second half of 2017 for at least 20 of the 30 pages in the sample. In their forums in early 2018, Facebook acknowledged problems with the API that resulted in the absence of some posts. Therefore, in this report the annual number of posts for 2017 is estimated based on doubling the volume of posts that appeared in the first six months of the year.

Posts that were produced during the sample time period but were removed by the pages themselves prior to the collection of data by the Center were not included in this study.

The total number of interactions for each post was the sum of all comments, shares and number of reactions (including clicking on icons for ‘like’ and other reactions such as ‘wow,’ ‘sad’ or ‘love.’)  In this study, the total number of interactions is the primary metric used to indicate audience engagement.

For some posts, the numbers of shares were not available through the Facebook API. For the sake of consistency, the numbers of shares were considered zero when compiling the total number of interactions for those posts.

The number of shares and comments are from the Facebook page URL only. If a page posted a link to a video located on another Facebook page, any data regarding shares and comments on that secondary page were not counted. For example, this April 11, 2016, video on Bill Nye’s page linked to a video on the GQ Facebook page. That post received 1,962 comments and seven shares on Bill Nye’s page at the time of capture, which were counted for this study. On the GQ page, that video received around 75,000 shares and more than 3,000 comments. Those 78,000 interactions were not included in this study since they did not appear on the specific science-related page in this sample.

The link provided by the Facebook API was the URL of the main link featured in each post. In many cases this was a link to the website of the same organization as the Facebook page. In other cases, the link was to another website produced by a different organization. In a few cases, posts did not include any links at all.

Human coding

In order to examine the specific content and format of posts from these Facebook pages, researchers performed detailed content analysis coding of a random sample of posts from Jan. 1 to June 30, 2017. To control for the different frequency of posts, the Center coded an equal number of posts – 250 – appearing during that six month period from each page. Half of the randomly selected posts appeared during the first three months of 2017, while the other half came from the next three months of 2017.¹⁵

For pages that did not have at least 250 posts during those six months, all the posts appearing during the six month period were coded.

For some posts originally selected for the sample, the Facebook post was available, but the content linked to from that post was no longer active. In those cases, those posts were excluded from the coding sample and replaced by another randomly selected post. (The details for these posts were still included in the historical data in this study.)

For each post, coders considered any text or video that appeared on the original Facebook page, along with any text or other information that appeared in the content that was linked to by that Facebook post. Comments were excluded. In total, 6,582 posts were included as part of the human coding sample. See the Appendix for details on the number of sampled posts.

Coded variables in this study were as follows:

• Primary science topic: The topic or research area that best fits the content of the post. There were 22 topics, although several were combined for the final analysis. Some posts were classified as having a “non-science” topic. If more than one topic area was discussed, the area that received more time or space was coded as primary.
• Primary storyline: The specific topic or theme of the post. There were 36 storylines, although some were later combined. Storylines were sometimes quite specific, such as the “March for Science on April 22, 2017,” and sometimes related to broader themes, such as vaccines or climate change. Many posts did not include mentions of any of the storylines and were given the equivalent of an “NA” for this variable. If two or more storylines were mentioned in a post, the storyline that received the most mentions was coded as primary.
• Primary frame: The main goal or focus of the post. There were 15 frames coded. If two or more frames were present in a post, researchers coded the focus that received the most time or space as primary.
• Link to external evidentiary research: The presence or absence of a link to external research in the post or the accompanying article. This usually included a link to a scientific journal article but could also include links to original research by government agencies or other institutions. For a link to be counted, it had to either have a hyperlink to the research or provide enough clear bibliographical information that a reader could easily find the research in question. Only research links external to the particular Facebook page counted. Therefore, if a post on NASA’s Facebook page included a link to original research that was conducted by NASA itself, it did not count as an external While some pages, such as Hashem Al-Ghaili’s Science Nature Page, occasionally place links to a scientific publication in their comment section, these were not included as external links in the post.
• Producer of content: The organization responsible for the creation of the content in the post. For many posts, the content was written and published by the same Facebook page where the post appeared. In some cases, posts link to articles that were originally produced by another organization. Coders logged the name of the organization responsible for the original text or video in the post. Once the coding was completed, researchers categorized the producers assigned to each post as either produced by the same organization running the Facebook page or a different organization. The producer code was considered to be the same organization if the post and accompanying website were both owned by the same company. For example, links from posts on the MythBusters Facebook page to discovery.com were considered the same organization since they are both owned by Discovery Communications Inc.. When a post linked to a website that included content from many producers, such as YouTube or Twitter, researchers followed the link to determine if the material appearing on that site was created by the same organization as the Facebook post or by a different organization.

To test the validity of the coding, four researchers classified the same set of 121 posts on five variables. For the three more complex variables, an additional 35 posts were also coded by each person. Intercoder agreement ranged from 80% to 97% across these five classifications. Krippendorf alpha ranged from .71 to .84.

Data of Twitter pages

Data regarding the number of followers for Twitter accounts discussed in this report was collected as of Jan. 31, 2018. Data regarding the number of tweets posted in 2017 was collected using Crimson Hexagon.