User Interface Design for Vending Machines

In the United States, many vending machines arrange their products in rows and columns. You would find that this in the case of Antares vending machines. To select a product, you type the letter of the row and the number of the column.

Generally the columns in all vending machines including Antares vending machines are labeled 1 through 10. That means that if you want to buy product C10, you have to push the buttons “C” and “10”. In a modern keyboard-based world, there is no “10” button. Instead, people type “1” followed by “0”. If one types “C”+”1”+”0”, it means that after you have typed “1”, product “C1” drops, and then you realize that there is no “0” button and you have bought the wrong product.

One solution is NOT to put so many items on a single row in your Antares vending machine. People have difficulty in making decisions if given too many options.

Another solution is to change the labels on the Antares vending machine so that there can be no buttons with two characters on them (like the “10” button)

Switch the rows and columns, so that the products are labeled “1A” through “1J” across the top row and “9A” through “9J” across the bottom. This can only apply if you don’t have more than nine rows.

The latest solution is one you can find in most recent vending machines. Here instead of calling the tenth coloumn”10”, they call it “0”. They also removed rows “1” and “0” so that there can be no confusion with “1” and “0”.

Some vending machine use numeric codes for all items rather than a letter and a digit. For example if a snack is product number 18, then you punch “1” “8”.