Interactions – Self Checkout

This week's assignment for my Physical Computing class was to observe the use of an interactive technology in public (link to full description). For this assignment I choose to focus my attention on the self-checkout machines that are available at the Home Depot. This type of device, which began to appear in retail locations a few years back, is still fraught with interaction challenges and obstacles. Therefore, I thought this would be the ideal subject.

My Expectations
Here is an overview of my assumptions regarding how the self-checkout machines should work: the shopper approaches the machine with a shopping cart and/or basket. The touchscreen monitor in the self-checkout kiosks display a prompt for the consumer to click a large button on the screen to initiate the checkout process. This is coupled with an audio prompt that instructs the user to take this action – “touch the screen to start your checkout”.

Once the user has selected to move forward with the checkout process, the machine asks him/her to scan the first item and place that item in a plastic bag that is placed above a surface next to the scanner that features a scale. This surface uses the weight of the bag to monitor that the shopper is not adding (or forgetting to add) any items to their shopping bags.

Once all of the goods have been scanned, the machine offers the shopper standard payment options such as cash, debit and credit card. The process to make payment with cash involves an interaction similar to purchasing a soda from a vending machine. The process for paying with debit and credit cards is navigated through the touchscreen.

Throughout this process one or two store clerks are responsible for monitoring several self-checkout kiosks. Their main role is to ensure that customer issues are quickly solved (rather than to police the customers and avoid theft).

Real-World Observations
On average the self-checkout at the Home Depot takes between 60 seconds and 4 minutes per person. The process for self-checkout seems to be simple for the most part, with some notable exceptions that cause a lot of user frustration. Now let’s briefly examine each step of this process.

For the most part, users did not have any issues initiating the purchased process. They were able to walk up to the self-checkout machines and get started without a hitch.

The process for scanning items was by far the biggest source of issues. The scanning itself was not a problem for any shopper. However, as described in my expectations above, the self-checkout kiosks feature a scale in the area where customers bag their purchases. This was the source of the confusion and issues that arose.

Many customers encountered one of two issues here: either they placed an item in the bag that the scale was not able to detect or they removed an item in the bag at a moment that the machine was not expecting – in either case a store clerk had to help the shopper finish his/her transaction. Here is a video from YouTube that shows an example of customers having this type of issue at a supermarket self-checkout line.

Once shoppers were able to get all of their items scanned, the payment process seemed to run smoothly.