Fifty years ago today, the first push button telephone was introduced to customers in Pennsylvania, USA. The push button phone was initially seen as a fashionable replacement to the standard rotary dial phones. But there was more to the new design than simply fashion.
Following the Second World War, US telecom companies decided to use of a string of seven numbers for telephone codes, and people worried how they’d be able to remember all seven of the digits, as well as how long it would take to dial them with a rotary phone.
As the concept of push button phones became more popular, the issue of creating a standardised layout for the buttons became a pressing issue of the day. Some telephone designers placed buttons in a circle to replicate a rotary dial, while others placed ‘1-2-3’ on the bottom row. But one man and his team conducted research into why people became confused when using push button phones. The result concluded that by having 1-2-3 on the top row, people could better cope.
John Karlin claimed, by using his rectangular arrangement followed people’s logical thoughts, and the keypad design he championed became an international standard.
With the introduction of mobile phones and touch screens, push button phones may have become obsolete. But Karlin’s 12-key design is still used, not only for telephones but for security locks, petrol pumps, ATMs, vending machines, calculators and all other keypads.
From 1945 to 1977, John Karlin, known as the ‘father of human-factors engineering,’ worked at Bell Labs. Human factor engineering is a field of psychology that studies brain processes and how it affects technology use.
Today, many of us are so familiar with Karlin’s original push button keypad layout that we may not even look at the keypad when using it. But that design was the result of many years studying how people interacted with push button phones.
John Karlin died in January 2013 aged 94.
