“UNEXPECTED ITEM IN BAGGING AREA!”
I hate self-service checkouts. Well, let me rephrase that. I love the idea of them: being able to move at my own pace, able to bag my items in the order I want, able to enjoy an illusion of privacy as I handle my own groceries. I even like the novelty of using the new technology. What I don’t love, though, is their UX. Slow machines that interrupt me with unexpected queries, failing completely the moment I deviate even slightly from the predefined workflow. Machines that force me to find an assistant the moment I do anything even slightly out of the ordinary, like rearrange my bags – assistants who are typically overstretched and otherwise preoccupied.
Why did it turn out like this? Why is it that, in the second decade of the third millenium, consumers are still facing systems with interfaces lifted straight out of the early 1990s?
I think there are a few reasons, and each lies behind at least one of four major issues auto-checkout systems suffer.
Issue 1: Rigid Workflows
The machine doesn’t make smart decisions, or let me short cut its workflows – e.g. if I’ve entered a debit card, I automatically want to pay by card, but the machine insists I remove the card, press ‘pay by card’ and try again. Users approaching terminals with expected workflows suffer a learning cost and lose confidence in their knowledge of how to handle the transaction.
Designers who take for granted the workflow the supermarket imagines users will take rather than practical insights into the ways shoppers actually work. Lack of attention to the ‘NATty principle’ (‘Never Ask Twice’). Assumption that users will read instructions rather than proceed on the basis of their existing expectations.
Users don’t think about tasks in the ways we hope they do, and if there’s a mismatch, help text will not guide users into your ways of thinking – they just don’t bother reading. Instead, study your users and see how they mentally group and divide certain kinds of tasks into stages of a process. And always, always allow for deviation.
Issue 2: Reliance on Store Staff
Autocheckouts rely too much on human supervisors arbitrating decisions, when assistants are usually in short supply and often busy directing customers to terminals. Users feel bad for having to demand the attention of visibly strained store staff. Customers feel helpless if staff are unavailable.
I’d guess a miscommunication about the context of the product. I strongly suspect that whereas the designers were assured that supervisors would always be on hand to help, supermarkets have ‘sold’ the service internally as a way to reduce supervisor workload. That would mean staffing managers under-resourcing autocheckout lanes, yet designers assuming a supervisor will always be able to help.
When your application makes a request of the user, be very diligent in investigating the costs of those requests in real-world deployments. Be realistic about the contexts your solution will be delivered to, and be frank with stakeholders about the situations where your product just won’t perform well.
Issue 3: Impatient Timeouts
Task timeouts are completely unrealistic. If I’m having trouble bagging something, and I take a little too long, the entire terminal closes down, and I can’t continue without a supervisor – even if I do eventually bag the item in question. Unconfident users feel they’re treated as being slow and incapable. Low-literacy users who typically read instructions repeatedly suffer a visible, social embarrassment as they repeatedly stumble on tasks.
This could be simply a lack of practical research, combined with hasty assumptions about how long something ‘should take’ – when research will indicate something very different.
Give users the chance to recover, or the ability to call an assistant without locking the entire terminal. Alternatively, subtly request the attention of the assistant without necessarily informing the user – so the assistant can judge the situation from afar and approach troubled users naturally.
Issue 4: Bag Panic
Autocheckouts don’t allow me to rebag items. If I have more than one bag, and try to take some off the scales before closing the transaction, the application locks down – even if user replaces item.
Naive assumptions that users would always have one small basket, and that they would always work to the supermarket’s imagined workflow.
Observe your users. Allow the application to fail gracefully – ideally, still allowing progress whilst assistant is being called. Research your users and test your assumptions with real-world usability testing. Treat workflow assumptions with healthy scepticism.