Anyone who knows me personally knows that I love to have a bit of a rant and a moan about things in life which are, for want of a better word, just a little... shitty. The little user experience niggles we put up with on a daily basis which could be so much better if people could be bothered to do something about them.

In this series I'll be running down my biggest peeves when it comes to just plain bad user experience, and this week I'm starting with self checkouts. Not just any self checkouts; specifically the ones at popular British supermarket and convenience store chain, Sainsbury's.

To be clear, I'm not an expert on the software engineering of POS systems; some of the peeves listed below may have perfectly valid explanations from a technical standpoint, but all I can go on is my experience as a user, who's frustrated by these systems on an almost daily basis.

Peeve 1: Your total is... wrong.

About a year ago I was helping to test a POS system used by a major retailer as the engineering team behind it worked to include a new running total feature which kept the total transaction price up to date as items are scanned in, automatically taking into account any promotions, discounts, and multi-buy offers as you went along.

Now it turns out that this isn't too difficult to implement if the back-end which feeds your POS system, like SAP or Oracle for example, supports it, but it's something which needs to be tested thoroughly, because when you break it down a POS system at its most basic is just a calculator. Its absolute minimum requirement is that it should be able to add, subtract, multiply and divide accurately, and spit out the correct total for the user at the end, so they know what they should pay.

The self checkouts at Sainsbury's don't meet this requirement in one fundamental way.

Because of the way the total is calculated and then displayed, users don't see any promotional discounts or multi-buy savings until they've either selected their payment method, or chosen to 'finish and pay', then gone back to the item screen, at which point the savings are shown on-screen.

You can see more clearly what I mean in this video by YouTube user Mustafa Arif.

This is an issue which has been noted by a number of people online, and some have even gone so far as to say that it's a scam, with Sainsbury's relying on people not noticing that they're being charged full price and missing out on discounts when they check out. To be absolutely clear: I tested to see if this was the case, and can confirm that when paying (either with card or cash), the total that you pay is correct, and you won't miss out on any deals. You just won't be shown what the actual total is until you either look at the display on the card reader or check your receipt.

So this isn't a conspiracy; Sainsbury's aren't trying to conceal savings from you and charge you more, and they aren't deliberately trying to make you do more work to figure out what you need to pay. They just aren't paying enough attention to what's important to users as they move through the process of checking out their groceries, and this seemingly tiny oversight has led to—you guessed it—a shitty user experience.

Peeve 2: Insert your card... wait, not yet.

Another frustration with the system at Sainsbury's is that if you want to pay with card, you've got to tell it beforehand. Now, this doesn't sound like a big deal, until you realise it's by design.

In other retailers, when you're ready to pay you insert your card into the reader and it tells the checkout kiosk 'Hey, they just inserted a card; I guess they want to use that to pay. I'll take things from here', and you punch in your PIN and all goes smoothly. At Sainsbury's, this communication still happens, but with a different result. Instead of just assuming that you want to pay with your card (because you've inserted your card into the reader, after all), the checkout kiosk flashes up a message saying 'Hey, you didn't tell me you were paying with card; take it out, go back a step, and touch the 'pay with card' option, then you can insert your card.'

The thing is, to flash up this message, the kiosk needs to recognise that you've inserted your card; at that point, wouldn't it be easier to just auto-select the card payment option and let you carry on? Why force the user to remove the card and go back, just to check an option which by now is redundant, because the system knows you want to pay by card. This isn't the case in Tesco, M&S, or any of the other major supermarkets I've tried, so why have Sainsbury's built this clumsy mechanic into their user flow? Maybe there's a good technical explanation, but to me it seems like... well, you get the idea.

Peeve 3: Select payment type... but not that one.

When it comes to interacting with buttons on-screen, sometimes there's a perfectly good reason to grey certain options out. In fact, there's been considerable debate over the merits of greying options out vs. hiding them completely, going back more than a decade. It makes sense to grey options out when they're not available to the user at that particular time, but will be at another point in their interaction. But if an option is never available, then why have it listed at all?

This is what annoys me most about the self checkout systems at Sainsbury's.

Recently, some of their larger stores have rolled out upgraded card readers which support contactless payments, but at present paying by contactless isn't supported at self checkout kiosks. That's an entirely different business decision which I'm sure Sainsbury's have a concrete strategy for, but for now it's no big deal; I suppose it makes sense to future-proof if you're buying that many new card readers and make sure you're getting ones which give you the option to switch on contactless payments at a later date if you choose to.

What you shouldn't do is have the option to pay by contactless on the self checkout screen, but grey it out so users can't select it. If it's not an option, don't show it at all. The only reason I can see that you would have the option there but greyed out is if you do accept contactless payment, but the reader is currently not working, or the transaction total is over the current contactless payment limit of £20. That way, you're letting the user know that it's an option which they can use next time they're in-store, and they'll surely appreciate knowing that the option's there for their next trip.

But if you don't accept contactless payment, having the option there and greying it out serves no purpose; it doesn't tell the user anything useful, and can lead to confusion when people see a contactless-capable reader, and the option to pay using a contactless payment method, but are then denied that option because the icon on-screen is greyed out.

In fact, EMVCo—the body behind the development of this kind of contactless technology, and the licensors of the contactless payment symbol—have pretty strict regulations about where the contactless payment symbol can and can't be used:

"A product that is not designed to facilitate contactless payment transactions is not a Contactless Product under this Agreement, and ... the Contactless Marks may not be used with such products ..."

— EMVCo Trademark License Agreement

And this is for good reason; to avoid confusion. Consumers should be able to see that symbol and have an immediate expectation of exactly what it means. Sainsbury's seem not to be particularly interested in avoiding user confusion, and have chosen to show the mark anyway, regardless of the fact that they don't actually accept contactless payments.


As I said at the beginning of this article, none of these issues are massive showstoppers; individually, they're irritating and are going to frustrate some people, but they're hardly likely to ruin somebody's day. But together, they're symbolic of a lack of effort on Sainsbury's' part to create a great user experience at their self checkout kiosks.

Of course, they have limitations to work within; some of the biggest frustrations I have with self checkout kiosks come from the NCR terminals themselves, and there's not a lot the retailer can do to remedy those niggles, but what I've outlined here they can control.

A multitude of other large retailers use these same terminals, running the same software, and most likely using the same back-end, but only Sainsbury's exhibits the issues I've talked about here, and it tells me that the problem isn't caused by the limitations of hardware or software, but in the limitations of Sainsbury's' understanding of good user experience design.

Update: August 31 2015

Breaking news! It seems that this week, Sainsburys have begun to roll out an updated interface for their kiosks. The new design is unlike any other self-checkout I've ever used... and that's the first of a series of new problems. Having to learn how to navigate their new system of menus and find buttons which aren't where I'm expecting them to be is a pain, and has slowed things down massively lately. (Not to mention the fact that, for whatever reason, this update has put about 80% of the kiosks at my local store out of action).

Now, doubtless, if other supermarkets jump on board with this new UI then gradually people will learn, so this isn't the end of the world, but right now Sainsburys are putting themselves in the awkward position of being first, and whilst this is usually a good thing in business it does mean that they're turning their customers into guinea pigs when it comes to adapting to the new system.

But it's not all change, though! You'll be pleased to hear that after spending x-amount of hours and money on this new (admittedly more visually pleasing, if a little alien for now) UI, it still doesn't calculate running totals/bonus-buy pricing as you go along, and it still throws a tantrum when you insert your card without warning it beforehand.

Oh, and this is how it notifies you that your payment was approved and everything is A-OK:

I hate to imagine what it looks like if your card gets declined.

I didn't really think they could, but somehow they've managed to make the experience even shittier that it was before with this kind of cavalier disregard for the most basic design principles.

Oustanding work. Now, where did I leave my Clubcard?