Once fickle and far less reliable than their human-operated counterparts, the self checkout machines in convenience stores now work well enough that in many stores, they’ve become the primary cashiers.
At the CVS near where I live, this is certainly the case.
The machines are clearly designed with a single imperative:
cut labor costs by any means possible make it as hard as possible for customers to screw up.
The buttons on the screen of the interface terminal are large and few. Customers aren’t overwhelmed with options, toggles, features, and so on. They are, rather, presented with the bare minimum (on the shopping landing page, customers only see buttons for accessibility, phone number lookup, use my own bag, and request help). Furthermore, some button prompts are automatically overridden, so that users are delivered error messages or similar when they skip a step they deem unnecessary to them (for example, the language prompt [English or Spanish] is overridden when they users begin checking out items, while the prompt for payment method is automatically skipped when the users begin the payment process).
The bar-code reader, meanwhile, is accompanied by a mirror perpendicular to it so that items may be checked out from various angles with greater ease.
Customers only rarely struggle with much of anything—but when they do, they exhibit considerably more frustration than when there is a holdup of some sort when checking out with a human cashier. This kind of behavior is similar to the social-cultural response to the fallibility of “self-driving cars”: even if they are significantly less prone to crashing than cars commandeered by people, the possibility that they might crash is a much greater talking point than the outrageously high fatality figures of crashes involving human error.
The key difference here, though, is that self-driving cars are just that: self-driving, and need not be attended to. The machine takes care of (almost) everything, and their interfaces reflect this: take a look at the interiors of some of the recent Tesla models—it looks more like the spartan workbench of a minimalist designer than a conventional vehicle’s cockpit.
This is far from the case with the self checkout machine at my CVS. There is not one screen but two: an interface for the checking out and an interface for the payment. There are numerous printed warnings bordering the interfaces—some variation on “cash and coins is not accepted” are splayed across more than four different surfaces local to the payment area.
This whole area is relatively utilitarian. Although our lives might be slightly more pleasant were this not the case, elegance and delight have historically played a subordinate role (or are altogether absent) in the design of commercial interactions and space.
In the case of the CVS self checkout machine, this is might have an intentional reason: aesthetic demands might end up aversely affecting the bottom line. Were it that, for example, the self checkout machines provided some kind of engaging or even faintly immersive experience, the customer might be ever so slightly less inclined to reach for one of the handful of items immodestly stuffed around the checkout area. In aggregate and over time, a more engaging checkout area could cause the company to lose quite a bit of money.
The administration of the economy of attention is perhaps the single most significant factor for the designers of these kinds of spaces. Nothing in the design of the CVS self checkout machine is unmarked by this consideration.