It's tempting to think that reading information on a webpage is essentially the same as reading information in a book. However, brain scans show that there is far more activity in people who read text containing hyperlinks than in those reading printed copies. The thinking is that the need to decide whether to click the link (or to resist the urge to click it) creates additional cognitive load, thereby distracting the reader from the content of the text.
"The need to evaluate links and make related navigational choices, while also processing a multiplicity of fleeting sensory stimuli, requires constant mental coordination and decision making, distracting the brain from the work of interpreting text or other information."
As teachers, therefore, we should consider keeping the number of hyperlinks and other distractions to a minimum. I know from my own experience that it's difficult to learn from materials that are split into small sections and require the user to keep clicking links to move to the next one.
The same is true of multimedia enhancements. Another study gave subjects either a plain text version of text, or a version enhanced with multimedia elements, and then asked them a number of questions about the content.
"The text-only viewer answered an average of 7.04 of the questions correctly, while the multimedia viewers answered just 5.98 correctly – a significant difference, according to the researchers. The subjects were also asked a series of questions about their perceptions of the presentation. The text-only readers found it to be more interesting, more educational, more understandable, and more enjoyable than did the multimedia viewers, and the multimedia viewers were much more likely to agree with the statement 'I did not learn anything from this presentation' than were the text-only readers. The multimedia technologies so common on the Web, the researchers concluded, 'would seem to limit, rather than enhance, information acquisition.'"
In a further similar study, subjects watched CNN-style news reports with and without the info graphics and scrolling items across the bottom of the screen.
"Subsequent tests found that the students who had watched the multimedia version remembered significantly fewer facts from the stories than those who had watched the simpler version. 'It appears', wrote the researchers, 'that this multimessage format exceeded viewers' attentional capacity.'"
The lesson here is that we need to be careful about presenting too much different information at the same time using different channels, e.g. auditory and visual. Carefully selected supporting information, e.g. a graph to illustrate what you're saying, can be effective, however.
It's difficult to stop students in online lessons from surfing the internet and looking at other things during the lesson. A study comparing the performance of students are allowed to use the internet in lectures with those who weren't found that while some were looking at unrelated things, such as social media, even those who were looking up related content performed less well in subsequent tests.
"The surfers, the researchers report, 'performed significantly poorer on immediate measures of memory for the to-be-learned content.'"
Research shows that working online might lead to a small expansion in our working memory, and that our brains quickly learn to swiftly focus attention on different things. It found that "many of us are developing neural circuitry that is customised for rapid and incisive spurts of directed attention" – but that this "hampers our ability to think deeply and creatively." As (Roman philosopher) Seneca said, "To be everywhere is to be nowhere."
Brains are not like computers – memories are not just standalone facts to be recalled and used to answer questions in exams. Memories can form part of a schema (i.e. part of our understanding of how to perform a skill, recognise an object or situation, etc.), our intellect and even our identity. Human memories are constantly updated as the brain that stored them is not the same brain that recalled them – we constantly reinterpret earlier memories and incorporate them into new schema.
Back in the 1970s, people worried that calculators would weaken students' grasp of mathematical concepts by doing the calculations for them. In fact the opposite was true – by doing the arithmetic and reducing our cognitive load, they led to better understanding of the key concepts.
Similarly, people thought that using the web was simply outsourcing the storage of knowledge and would give us quick and easy access to a huge database of facts, but "The calculator, a powerful but highly specialised tool, turned out to be an aid to memory. The web is a technology of forgetfulness."
There's an irony that technology designed to help us with a task also often numbs us or removes us from it. Clocks and calendars mean that we no longer have to pay attention to the passage of the sun or the rotation of the Earth, powered looms stopped people from needing to feel the cloth, farmers sit in air-conditioned machinery and no longer touch the earth or the crops, and GPS devices take us to exactly where we want to go, but we have no idea where we are or how to read geographical features.
This is also true of assistive technology in the classroom. In one experiment, subjects were required to solve a logic puzzle – some using a software tool that only allowed them to make the necessary moves, and others using software that suggested possible next moves:
"In the early stages of solving the puzzle, the group using the helpful software made correct moves more quickly than the other group, as would be expected. But as the test proceeded, the proficiency of the members of the group using the bare-bones software increased more rapidly. In the end, those using the unhelpful program were able to solve the puzzle more quickly and with fewer wrong moves."
A few years ago I read another book about how the internet has changed the way people think. It was a collection of articles by different people, many of them academics. The consensus was that the web is a good thing because it allows people to find other studies and check that they're not duplicating research.
However, a study of the academic papers published since WWII and the number of citations shows that the number of citations has actually declined since students moved on-line - people tend to do narrower research on-line than they do in libraries.
"The quicker that scholars are able to 'find prevailing opinion', wrote [the author of the study], the more likely they are 'to follow it, leading to more citations referencing fewer articles.'"
As it's easier to search for facts on-line than in books, our brains have less incentive to take on the work of remembering.
"Human beings are 'cognitive misers', a half-century of research has shown. If we can offload or otherwise avoid mental work, we generally will, even if it's not in our best interest."
An interesting 2011 study at Columbia University also showed that thinking that facts are available on a computer stops us from remembering them. Subjects were asked to type simple statements of fact into a computer. Half of them were told that the facts would be stored, and the rest were told that they would be erased.
"Afterward, the researchers asked the subjects to write down as many of the statements as they could remember. Those who believed the facts had been recorded in the computer demonstrated much weaker recall than did those who assumed that the facts would not be stored."
Does taking photos help us to remember? It turns out that taking digital pictures of things makes us less likely to remember them. One source of evidence for this came from a study in which subjects were given a tour of an art gallery – half were asked to take photos and half not to. Those who didn't take pictures had better recall of what they'd seen.
"If prints or snapshots glued to the pages of photo albums served as aides-memoire, digital pictures stored in intangible data appear to have the opposite effect, rendering the mind less absorbent. The popular expression 'pics or it didn't happen' gets it backwards."
If you're interested in the idea of what we remember of our experiences, Daniel Kahneman describes the idea of the "experiencing self" and the "remembering self" in his book, Thinking Fast and Slow, which I think is well worth reading.
I'm sure we've all seen "the illusion of knowledge", where a student tells us that they know how to do something (because they remember hearing about it), but in actual fact they can't do it. Finding information online creates a similar effect - we struggle to distinguish things we know from things we've looked up.
"…when people call up information through their phones or other computers, they often end up suffering delusions of intelligence. They feel as though 'their own mental capacities' had generated the information, not their devices."
These two effects lead people to feel that they know more about the world around them when they actually know less.
"That unhappy insight probably helps explain society's current gullibility crisis, with its attendant plague of propaganda, dogma and venom. If your phone has blunted your powers of discernment, you'll believe anything it tells you. And you won't hesitate to share deceptive information with others. A 2018 MIT study of message threads on Twitter, spanning more than 4.5 million tweets posted over ten years, found that fabricated or otherwise misleading stories are 70 percent more likely to be retweeted than factual ones."
We all know that mobile phones are a distraction and can disrupt sleep. I already tell students that schools that have banned mobile phones get better grades (the effect being more marked amongst low achievers) and disrupt sleep.
"In a … 2014 study, psychologists at the University of Southern Maine found that people who had their phones in view, albeit turned off, during two demanding tests of attention and cognition made significantly more errors than did a control group whose phones remained out of sight. When the researchers gave the participants a set of easier tests, however, they found that the two groups performed about the same. That makes sense. If our minds aren't being taxed, we can spare the cognitive capacity that our phones siphon off."
"The researchers found that the students who didn't bring their phones to the classroom scored a full letter grade higher on a test of the material presented than those who had their phones with them. It didn't matter whether the students who had their phones used them or not."
"Imagine combining a mailbox, a newspaper, a TV, a radio, a photo album, a public library, a personal diary and a boisterous party attended by everyone you know, and then compressing them all into a single, small, radiant object. That's what a smartphone represents to us."
This blog is a summary of the content from Nicholas Carr's book The Shallows that is relevant to teaching on-line. The book also contains additional detail about brain plasticity and people's concerns about other new technologies such as writing, clocks, books and broadcast media. I have omitted citations for brevity but they are all in the book, the Kindle version of which is often on offer.
This blog was originally written in August 2021.