It’s hard to imagine it now, but when the Sony Walkman came out it was a revolution in the way we listen to music. Within two months of its 1979 launch Sony had sold 30 000 units around the world, a number which would swell to 50 million by the end of the decade.

Its success, according to Drew Boyd, demonstrated the effectiveness of an innovation technique called Subtraction, one of five methods he teaches when training people to think more creatively. As the executive director of the Master of Science in Marketing Program and assistant professor of Marketing and Innovation at the University of Cincinnati, Drew spends his time training smart people to become more innovative, by doing the opposite of what they are usually told to do.

As he summarised for Coca-Cola Journey USA's The Opener column, Sony took a cassette recorder, subtracted its recording function, and hey presto – the Walkman was born.

Rather than telling people to think outside the box, Drew asked them to think inside the box, and work with what they have at hand.  

“Subtraction is one of five simple techniques anyone can use to produce new ideas,” Drew said. “The traditional view of creativity requires thinking “outside the box.” Starting with the problem and then brainstorming without restraint. Stretching far afield to find that breakthrough idea.”

These five techniques combine to form what Drew refers to as Systematic Inventive Thinking (SIT) as they are based on easily recognisable patterns used for centuries to create new solutions. He lists them as:

1. Subtraction: Innovative products and services often have something removed, usually something previously thought to be essential. Subtracting the recording function made the Walkman a breakthrough.

2. Task Unification: This technique brings tasks together, unifying them within one component of an innovation, usually a component that was previously thought to be unrelated to that task. Straps on backpacks are shaped so that they press softly into the wearer’s shoulders at strategically located “shiatsu points” to provide a soothing massage sensation.

3. Multiplication: Innovative products and services often contain a component that’s been copied but changed in a way that might seem unnecessary or redundant. In cameras, repeatedly firing the flash reduces “red-eye.”

4. Division: Some products and services emerge with a component divided out and placed in a new location or appearing at a different time. Dividing out the function of an oven and placing it elsewhere in the kitchen creates a warming drawer.

5. Attribute Dependency: Two unrelated product attributes can be correlated with each other. As one attribute changes, another changes. Transition sunglasses darken as outside light gets brighter.

According to Drew the approach works because it forces participants to re-frame how they generate ideas.

“People think the way to innovate is to start with a well-defined problem and then think of solutions,” Drew said. “Our method reverses that belief, we start with a conceptual solution and then work back to the problem it solves.”

Drew also points out that in most cases the best solutions are deceptively simple, and usually “right under our noses”.

“People think you need to go outside your current domain to innovate, the opposite is true, the most surprising ideas are right nearby,” Drew said. “We have a nickname for “The Closed World”…we call it “Inside the Box.”