Andrew Guess

• Professor (Assistant) at Princeton University

An enormous body of literature argues that recommendation algorithms drive political polarization by creating “filter bubbles” and “rabbit holes.” Using four experiments with nearly 9,000 participants, we show that manipulating algorithmic recommendations to create these conditions has limited effects on opinions. Our experiments employ a custom-bu...

The shift of public discourse to online platforms has intensified the debate over content moderation by platforms and the regulation of online speech. Designing rules that are met with wide acceptance requires learning about public preferences. We present a visual vignette study using a sample (N = 2,622) of German and U.S. citizens that were expos...

The use of individual-level browsing data, that is, the records of a person’s visits to online content through a desktop or mobile browser, is of increasing importance for social scientists. Browsing data have characteristics that raise many questions for statistical analysis, yet to date, little hands-on guidance on how to handle them exists. Revi...

We study the effect of Facebook and Instagram access on political beliefs, attitudes, and behavior by randomizing a subset of 19,857 Facebook users and 15,585 Instagram users to deactivate their accounts for 6 wk before the 2020 U.S. election. We report four key findings. First, both Facebook and Instagram deactivation reduced an index of political...

The spread of misinformation through media and social networks threatens many aspects of society, including public health and the state of democracies. One approach to mitigating the effect of misinformation focuses on individual-level interventions, equipping policymakers and the public with essential tools to curb the spread and influence of fals...

Many critics raise concerns about the prevalence of ‘echo chambers’ on social media and their potential role in increasing political polarization. However, the lack of available data and the challenges of conducting large-scale field experiments have made it difficult to assess the scope of the problem1,2. Here we present data from 2020 for the ent...

Does Facebook enable ideological segregation in political news consumption? We analyzed exposure to news during the US 2020 election using aggregated data for 208 million US Facebook users. We compared the inventory of all political news that users could have seen in their feeds with the information that they saw (after algorithmic curation) and th...

We studied the effects of exposure to reshared content on Facebook during the 2020 US election by assigning a random set of consenting, US-based users to feeds that did not contain any reshares over a 3-month period. We find that removing reshared content substantially decreases the amount of political news, including content from untrustworthy sou...

We investigated the effects of Facebook's and Instagram's feed algorithms during the 2020 US election. We assigned a sample of consenting users to reverse-chronologically-ordered feeds instead of the default algorithms. Moving users out of algorithmic feeds substantially decreased the time they spent on the platforms and their activity. The chronol...

In this note, we provide direct evidence of cheating in online assessments of political knowledge. We combine survey responses with web tracking data of a German and a US online panel to assess whether people turn to external sources for answers. We observe item-level prevalence rates of cheating that range from 0 to 12 percent depending on questio...

We used supervised machine-learning techniques to examine ideological asymmetries in online rumor transmission. Although liberals were more likely than conservatives to communicate in general about the 2013 Boston Marathon bombings (Study 1, N = 26,422) and 2020 death of the sex trafficker Jeffrey Epstein (Study 2, N = 141,670), conservatives were...

As the primary arena for viral misinformation shifts toward transnational threats, the search continues for scalable countermeasures compatible with principles of transparency and free expression. We conducted a randomized field experiment evaluating the impact of source credibility labels embedded in users’ social feeds and search results pages. B...

Digital literacy is receiving increased scholarly attention as a potential explanatory factor in the spread of misinformation and other online pathologies. As a concept, however, it remains surprisingly elusive, with little consensus on definitions or measures. We provide a digital literacy framework for political scientists and test survey items t...

Discussions around declining trust in the US media can be vague about its effects. One classic answer comes from the persuasion literature, in which source credibility plays a key role. However, existing research almost universally takes credibility as a given. To overcome the potentially severe confounding that can result from this, we create a hy...

Widespread misperceptions about COVID-19 and the novel coronavirus threaten to exacerbate the severity of the pandemic. We conducted preregistered survey experiments in the United States, Great Britain and Canada examining the effectiveness of fact-checks that seek to correct these false or unsupported beliefs. Across three countries with differing...

Significance Many argue that partisan media coverage creates political polarization by pushing people’s opinions to extremes, but evidence is mixed. We instead propose that partisan media coverage can cause polarization by altering people’s social connections and reorganizing social networks along political lines. Using computational modeling and s...

Increasing levels of political animosity in the United States invite speculation about whether polarization extends to aspects of daily life. However, empirical study about the relationship between political ideologies and lifestyle choices is limited by a lack of comprehensive data. In this research, we combine survey and Facebook Page “likes” dat...

Political elites sometimes seek to delegitimize election results using unsubstantiated claims of fraud. Most recently, Donald Trump sought to overturn his loss in the 2020 US presidential election by falsely alleging widespread fraud. Our study provides new evidence demonstrating the corrosive effect of fraud claims like these on trust in the elect...

Significance Although Americans believe the confusion caused by false news is extensive, relatively few indicate having seen or shared it—a discrepancy suggesting that members of the public may not only have a hard time identifying false news but fail to recognize their own deficiencies at doing so. If people incorrectly see themselves as highly sk...

We introduce the rationale for a new peer-reviewed scholarly journal, the Journal of Quantitative Description: Digital Media. The journal is intended to create a new venue for research on digital media and address several deficiencies in the current social science publishing landscape. First, descriptive research is undersupplied and undervalued. S...

Does the internet facilitate selective exposure to politically congenial content? To answer this question, I introduce and validate large‐N behavioral data on Americans' online media consumption in both 2015 and 2016. I then construct a simple measure of media diet slant and use machine classification to identify individual articles related to news...

Objectives To assess the quantity and type of vaccine-related information Americans consume online and its relationship to social media use and attitudes toward vaccines. Methods Analysis of individual-level web browsing data linked with survey responses from representative samples of Americans collected between October 2016 and February 2019. Re...

Significance Few people are prepared to effectively navigate the online information environment. This global deficit in digital media literacy has been identified as a critical factor explaining widespread belief in online misinformation, leading to changes in education policy and the design of technology platforms. However, little rigorous evidenc...

Although commentators frequently warn about echo chambers, little is known about the volume or slant of political misinformation that people consume online, the effects of social media and fact checking on exposure, or the effects of political misinformation on behaviour. Here, we evaluate these questions for websites that publish factually dubious...

Does Counter-Attitudinal Information Cause Backlash? Results from Three Large Survey Experiments – CORRIGENDUM - Andrew Guess, Alexander Coppock

Concern has grown since the 2016 presidential election about the prevalence of misinforma-tion in American politics and the ways social media has potentially exacerbated its reach and influence. In this report, we assess the quality and quantity of information flows during the 2018 midterm election campaign, focusing specifically on two new forms o...

So-called “fake news” has renewed concerns about the prevalence and effects of misinformation in political campaigns. Given the potential for widespread dissemination of this material, we examine the individual-level characteristics associated with sharing false articles during the 2016 U.S. presidential campaign. To do so, we uniquely link an orig...

Several theoretical perspectives suggest that when individuals are exposed to counter-attitudinal evidence or arguments, their pre-existing opinions and beliefs are reinforced, resulting in a phenomenon sometimes known as ‘backlash’. This article formalizes the concept of backlash and specifies how it can be measured. It then presents the results f...

How accurate are survey-based measures of social media use, in particular about political topics? We answer this question by linking original survey data collected during the U.S. 2016 election campaign with respondents’ observed social media activity. We use supervised machine learning to classify whether these Twitter and Facebook account data ar...

Is the expansion of media choice good for democracy? Not according to critics who decry “echo chambers,” “ filter bubbles,” and “information cocoons” — the highly polarized, ideologically homogeneous forms of news and media consumption that are facilitated by technology. However, these claims overstate the prevalence and severity of these patterns,...

This study rigorously compares the effectiveness of online mobilization appeals via two randomized field experiments conducted over the social microblogging service Twitter. In the process, we demonstrate a methodological innovation designed to capture social effects by exogenously inducing network behavior. In both experiments, we find that direct...

Self-reported measures of media exposure are plagued with error and questions about validity. Since they are essential to studying media effects, a substantial literature has explored the shortcomings of these measures, tested proxies, and proposed refinements. But lacking an objective baseline, such investigations can only make relative comparison...

It is well known that existing measures of self-reported media exposure are potentially unreliable. Various studies have explored the causes of such measurement error, such as social desirability bias, and have tested proxies such as political knowledge. However, lacking an objective baseline, investigations of this sort still rely solely on survey...