4. Product Design

Design Principles – Part 4 of 5

Universal Principles of Design, a book describing 125 interdisciplinary principles, is a fascinating reference. I extract 25 of those principles and offer relevant examples in a series of five blogs.

Today’s topics – product design:

  1. Aesthetic-Usability Effect
  2. Contour Bias
  3. Horror Vacui
  4. Ockham’s Razor
  5. Wabi-Sabi

Aesthetic-Usability Effect

“Aesthetic designs are perceived as easier to use than less-aesthetic designs.”

Aesthetic Usability CarPeople perceive aesthetically pleasing designs to be easier to use than less-aesthetic designs – whether they are or not. The effect has implications for the acceptance, use, and perceived performance of a design.

Aesthetic Usability iPhone

Aesthetic designs are more readily accepted. As a result, people are more tolerant of design problems that arise. Positive feelings towards a design encourage consumer affection, loyalty, and patience – all factors in the acceptance and long-term success of a design.

Aesthetic designs evoke positive feelings leading to ease of use, acceptance, and long-term use. They are purported to promote creative thinking and problem solving.

Contour Bias

“A tendency to favour objects with contours over objects with sharp angles or points.“

Contour Bias KettleContour Bias Kettle

Objects that feature sharp angles or pointed edges activate the region of the human brain that is normally involved in fear processing. This fear response impacts how the object is perceived.

Should all objects be made round to increase their appeal? Some objects naturally carry a positive emotional bias (stuffed animal) or a negative bias (sharp knife). Some are emotionally bias neutral. Biases aside, angled objects elicit a deeper level of processing, but in effect are more interesting to view.

Consider contour bias in designs where environments are emotionally neutral. Pointy and angular items attract attention and provoke thought.

Horror Vacui

“A tendency to favour filling blank spaces with objects and elements over leaving spaces blank or empty.”

Horror VacuiHorror vacui, Latin for “fear of emptiness”, is a desire to fill vacant spaces with information or objects. It is used to describe a style of art and design that leaves no empty space. Examples are newspapers, comic books, and even websites.

Research shows an inverse relationship between horror vacui and value perception: when horror vacui increases, perceived value decreases.

Horror Vacui Shop WindowsHorror Vacui EmptinessIn a survey of clothing stores where merchandise was displayed in a store window, shops filled with mannequins, merchandise, and signage were perceived to have lower prices and less brand prestige. Conversely, high-end boutiques featuring a few items were perceived to be more expensive and have greater status.

For those accustomed to having more, less is more. For those familiar with having less, more is more! Those who have more are generally considered to be well-educated and wealthier; those who have less are considered to be less-educated and poorer.

Market to high-end clients using minimalism and to budget-conscious consumers using horror vacui.

Ockham’s Razor

“Given a choice between functionally equivalent designs, the simplest design should be selected. ”

Ockham's Razor clean living room arrangementI chose this principle because of its unusual name. It is attributed to William of Ockham, a 14th century friar and logician.

When designing a functional item, keep it simple, clean, and pure. Remove unnecessary elements to increase the item’s functionality and efficiency and to reduce unanticipated consequences.

Ikea items, with their trademark simplicity and functionality, characterize the Ockham’s Razor principle.


“Objects and environments that embody naturalness, simplicity, and subtle imperfection achieve a deeper, more meaningful aesthetic.”

Wabi Sabi table and chairsThis is a Japanese philosophy and aesthetic that favours the subtle imperfections of hand craftsmanship (such as a nubby woven wool rug) and beauty achieved over time (such as the smoothness of a weathered outdoor sculpture).

Objects gain value through use and age.

This is an aesthetic that embraces the impermanence, imperfection, and incompleteness found in natural materials and organic forms.

Next: Part 5 – User-Interface Design

Related articles