While I agree with Mr Jeffrey Law (Don’t ask supermarket staff to do everything at self-checkout counters, Jan 19), the question is whether supermarket self-checkout is as efficient as it is made out to be.

Often, you still have to wait in line. The checkout kiosks bleat and flash when you fail to set a purchase down in the right spot. Scanning items can be hit-or-miss – wave a barcode too vigorously in front of an unresponsive machine, and suddenly you’ve scanned it two or three times. 

Then you need to locate the usually lone employee charged with supervising all the finicky kiosks, who will show her exasperation while scanning her ID badge and tapping the kiosk’s touch screen from pure muscle memory. 

There is little evidence that self-checkout is reliably faster than the traditional cashier system, and that feel of convenience has always been largely a trick of perception. 

Trained cashiers can scan and bag goods faster than even the most enthusiastic shopper.

But actual checkout speed tells only part of the story.

Self-checkout has a psychological effect: As long as the shopper is taking an active part, it seems to go faster.

But sometimes the user is a less digitally savvy senior forced to use a kiosk because there aren’t enough cashier counters open.

There is also the issue of theft, as the act of bagging your own stuff creates opportunities to make it out the door without paying for everything, including pilfered plastic bags.

Losses from unscanned and mis-scanned items at poorly designed kiosks are a trade-off that retailers are well aware of. 

The self-checkout system is not about efficiency or convenience for companies. It is about saving costs by making customers do the scanning and bagging instead of hiring cashiers.  

Roland Paul Ang