What telephones can tell you about good design

🌈 Abstract

The article discusses the design principles behind the layout of telephone keypads, drawing insights from a study conducted at Bell Labs in the 1950s. It explores how the chosen layout, which has become the industry standard, was not necessarily the fastest or most accurate, but was selected based on user preferences and logical considerations.

🙋 Q&A

[01] What telephones can tell you about good design

1. What were the key design goals that the researchers at Bell Labs were trying to achieve with the telephone keypad layout?

• The researchers were looking for a faster and more accurate way for users to dial, using buttons instead of a rotary dial. The goal was to reduce the amount of wrong numbers dialed and the connection time, making it easier for telephone exchanges to handle the increasing number of phone calls.

2. What were some of the alternative layouts that were tested, and how did they perform compared to the final chosen layout?

• The researchers tested a number of possible layouts for the keypad, including the familiar calculator layout, which was rejected as it was unintuitive and did not perform significantly better.
• The Vertical Columns layout had the fewest errors, but was the least preferred by users.
• The Horizontal Rows layout was the most popular with users, but was the slowest to use.
• The Three-By-Three-Plus-One layout, which became the standard, was chosen as it was the most logical for the majority of people, even though it was not the fastest or least error-prone.

3. What were some of the key design principles highlighted by the telephone keypad layout example?

• User preferences do not necessarily align with what works best in practice.
• The fastest solution is not always the best, as other factors like accuracy, ease of use, and emotional engagement also contribute to the user experience.
• The optimal design solution depends on the specific task, as typing numbers on a telephone is different from typing on a calculator.
• Familiarity and standardization can be important, even if the current approach is not ideal.
• Human cognition and behavior have a greater impact on performance than physical design factors.

[02] The impact of the telephone keypad layout

1. What is the estimated impact of the chosen telephone keypad layout?

• The chosen layout has been used approximately 40 trillion times since it was designed, and the world has saved a collective one million person-years of time as a result.

2. How does this example demonstrate the importance of considering various design factors beyond just user preferences?

• The article highlights that user preferences, usability, and engineering constraints all need to be balanced when designing a product. The chosen layout was not the fastest or most accurate, but it was the most logical and intuitive for the majority of users.
• This demonstrates the need to gather feedback and insights from real user testing, rather than relying solely on self-reported preferences.

3. What is the key takeaway about the role of human cognition in product design?

• The article notes that individual differences in how people pause and process information when entering numbers had a greater impact on performance than the physical design of the keypad.
• This emphasizes the importance of understanding the user's cognitive processes and behaviors when designing products, rather than focusing solely on the physical interface.