The words are intoned with reverence: critical thinking. If only, if only, students were taught critical thinking, they wouldn’t be taken in by flat earthers, Holocaust deniers, astroturfing lobbyists, GMO fearmongers, TiKTok scammers, and the army of bad actors, swindlers, and trolls who send them headfirst into digital rabbit holes. Forget about 21st century skills. Socrates had it right in the 4th century BCE. Sequential reasoning. Claims tied to evidence. Painstaking analysis. Clearheaded logic.

Need to equip today’s students for the digital age? You can do no better than to start with The Republic.

Here’s the thing, though. For all of its virtues—abundant and essential, let us not forget—critical thinking consumes modern society’s scarcest resource: our attention. A barrage of messages sends our heads spinning trying to determine, too often fruitlessly, where to focus. It’s flattering to think that when we engage with a shady website, uncovering its hidden assumptions and poking holes in its flawed logic, we emerge better informed and more able to unmask the next canard. But the opposite is often the case. We fork over attention and allow our energy to be hijacked. Our cognitive fuel tank runs on fumes just when we need high octane to evaluate sources that truly merit our attention.

The Nobel prize-winning psychologist, Herbert Simon, saw all of this coming at the first light of the information age. Simon postulated that the overabundance of one thing necessarily leads to scarcity of another. Information overload creates a “poverty of attention.” Simon presciently framed the question facing our screen-obsessed, Google-drenched age: How do we “allocate attention efficiently among the overabundance of information sources that might consume it?”

Before attention can be allocated, it must be preserved. To do this we need to develop the yang to critical thinking’s yin. Critical ignoring is critical thinking’s essential counterpart: the ability to quickly decide whether an item that comes across our feed is worthy of attention and, if not, to ignore it, move on, and locate a better source.

Teaching Students to Evaluate Digital Sources

Critical ignoring runs counter to common ways we teach students to evaluate digital sources: to regard them pretty much like any other piece of writing, with an appendage of internet-related tips tacked on. Read carefully to see if the point of view is objective and impartial. Then, pay attention to the About page. Look at the recency of updates. Check if the links are functional. Spot spelling or grammatical errors. Locate a physical address. Examine the URL.

Not only do these ubiquitous “what to look for” lists sap attention with questions that are easily gamed, they violate what the most skilled users of the internet do to vet digital sources.

We know because we observed them. In 2017, Sarah McGrew and I traveled to New York and Washington D.C. to watch how professional fact checkers at the nation’s most prestigious publications evaluated unfamiliar digital sources. We then compared their responses to other highly intelligent, critical thinkers: professors from five different universities and a group of digital natives, among the talented 4% admitted to Stanford University. When these two groups were asked to evaluate an article on the American College of Pediatricians website, they tended to do what critical thinkers do. They started at the top, noting the organization’s name and official-looking logo; they registered that the site ended in “.org,” which they believed conferred legitimacy; the article was arrayed as a scientific research report, complete with abstract, subheads, and a list of scholarly references; and the language was dispassionate and measured, what one would expect from a report by a professional organization.

Students need to understand that there is no such thing as free-floating information. Information comes from somewhere. That somewhere needs to be checked.

Fact checkers, on the other hand, ignored all these features. To conserve attention and quickly decide if the site was a worthy investment, they gave it a momentary glance and then did something that, on its face, seems contradictory. They left it. They put the name of the organization into their browser and opened multiple tabs, a practice we call lateral reading (for more on this concept, visit In a minute or two, they learned that notwithstanding the group’s official sounding name, it was not the main organization of pediatricians (that would be the 67,000-member American Academy of Pediatrics), but a splinter group that broke off from the parent group over the issue of adoption by same-sex couples. The American College of Pediatrics embraces corporal punishment and promotes “conversion therapy,” a procedure banned in 22 states and the District of Columbia. The Southern Poverty Law Center has labeled it a “hate group” that “masquerades as the premier U.S. association of pediatricians.”

Dwelling on an unfamiliar website’s about page, granting importance to a dot-org URL (please don’t), sizing up a site by its “look” and whether its language is measured are features that take in today’s digital natives. In a recent national study, we asked 3,446 high school students to evaluate the credibility of a series of websites, including one that claims to “disseminate factual reports” about climate change. Ninety-six percent failed to learn that the site was a front group backed by the fossil fuel industry—information nearly instantly obtainable by ignoring its many reports, graphs, and analyses and searching the organization on the open internet. Despite instructions that they could do anything they normally would, including leaving the source and searching elsewhere, the vast majority of students remained glued to the original site.

AI’s Growing Influence

As generative AI invades every crevice of modern life, the ability to quickly locate and evaluate the source of information becomes even more imperative. Designed to be persuasive, not accurate, and predicated on statistical probabilities of word combinations (infinitely more powerful but based on the same principle as the predictive feature when texting on your phone), large language models mash up information like a Vitamix mashes up ingredients in a green smoothie. Before accepting answers prone to “hallucinations” and citations to articles that don’t exist, students need to understand that there is no such thing as free-floating information. Information comes from somewhere. That somewhere needs to be checked.

The philosopher Michael Lynch wrote that the internet is “both the world’s best fact checker and the world’s best bias confirmer—often at the same time.” True, today’s students operate digital devices with astonishing fluency. But operating devices doesn’t mean that students have the tools to evaluate the information these devices spit out. We have allowed today’s students to speed along the information superhighway without so much as a driver’s permit. As educators, we must do everything we can to cultivate students’ critical thinking. But in an age where we turn to a screen to learn about the world, the first step of critical thinking is to determine if something is worthy of thinking critically about.

Fickle and finite, attention is too precious to waste.

Sam Wineburg is the Margaret Jacks Professor of Education, Emeritus at Stanford University. His latest book, with co-author Mike Caulfield, is Verified: How to Think Straight, Get Duped Less, and Make Better Decisions about What to Believe Online. Learn more at


Lynch, M.P. (2016, March 9). Googling is believing: Trumping the informed citizen. The New York Times.

Meriam Library, California State University, Chico. (2010, September 17). Evaluating Information – Applying the CRAAP Test.

Simon, H.A. (1971). Designing organizations for an information-rich world. In M. Greenberger (Ed.), Computers, communications, and the public interest. The Johns Hopkins Press.

Stanford Graduate School of Education. (2021, May 27). National study of high school students’ digital skills paints worrying portrait, Stanford researchers say.

Wineburg, S., & McGrath, S. (2019). Lateral reading and the nature of expertise: Reading less and learning more when evaluating digital information. Teachers College Record, 121(11), 1–40.

Wineburg, S., & Ziv, N. (2019, December 5). The meaninglessness of the .org domain. The New York Times.