Why Researchers Should Consider Swiping as a Psychological Measure

According to a 2016 report, we typically touch our smartphones about 2,600 times per day — and that is a low estimate. From scrolling to double-tapping to swiping left and right, we are constantly interacting with our smartphones through touch-and-swipe gestures. Surprisingly, very little research had investigated the cognitive mechanisms of swiping, and what they can reveal about the subcomponents of our decision process.

A reliance on button presses

The vast majority of cognitive psychology research collects data through button presses. In a typical cognitive task, a participant might be asked to press a button when a target item shows up, and press a different button (or no button at all) when a non-target item shows up. In such tasks, researchers are interested not only in the accuracy of participants' responses but also in the time it takes them to respond. Reaction times are important because they reveal information about performance beyond accuracy alone.

For example, a participant may show a speed-accuracy tradeoff, where they take longer to respond to certain questions than others. An apparent improvement in accuracy might indicate learning, but it might also indicate that the participant has slowed down their responses in order to be more accurate. Moreover, reaction times might be indicative of uncertainty in a response. Difficult items tend to produce both longer reaction times and more errors, compared to easier items. In this case, reaction times can be used to estimate the difficulty and reliability of a participant's responses.

Touch-and-swipe as a psychological measure?

Although button presses have long been the standard tool for collecting responses in cognitive psychology studies, new research suggests touch-and-swipe gestures may provide even more information about the cognitive processes that precede our decisions.

A new study by Michelle Kramer and colleagues, published this month in Perception, examined data from a large population of 15,000+ people who downloaded and played a phone game called Airport Scanner. In each trial, participants had to swipe an item to either the top of the screen (for allowed items) or the bottom of the screen (for prohibited items). Typically, psychologists would examine a single measure of reaction time — for example, the total time it took a participant to sort the item, from the moment the item appeared on the screen, until it had been correctly (or incorrectly) sorted. But Kramer and colleagues subdivided this total time measure into two distinct components: time to touch and time to swipe.

By considering these two components separately, the researchers discovered that only one of these measures was predictive of accuracy: time to swipe. When comparing correct and incorrect trials, there was a clear difference in time-to-swipe. Specifically, participants took about 11% longer to complete swipes (after having touched the screen) in incorrect trials compared to correct trials. No such difference was found for time-to-touch. That is, the time it took participants to touch the screen once an item appeared was not at all predictive of the eventual accuracy of their responses.

The future of touch-and-swipe

Although there is still much research to be done to understand swiping gestures — Kramer and colleagues admit this study is just a proof-of-concept — the article provides compelling evidence that touch-and-swipe gestures provide more information than can be gleaned from button presses alone. Given the ubiquity of touch-and-swipe gestures on our hand-held devices, considering these new measures will not only illuminate the decision-making process, but it will also bring psychology research more in line with the everyday technological practices of the 21st century.