“What if we made part of it different?”

Local Quality: Change of an object’s structure from uniform to non-uniform.

Constant linear speed vs constant angular speed

Optical and magnetic disks can be build so that they rotate at a constant speed (constant angular speed – CAV) or so that as the read head moves from the centre to the perimeter of the disk, the disk moves under the head at a consistent speed (constant linear speed – CLV).  CAV is less complex and expensive and supports random access to data, because the spinning media doesn’t need to have its speed constantly adjusted when the head moves from the centre to the edge and back.  CLV allows greater density of data storage.

Both CLV and CAV represent a result from Principle 3 thinking – CAV has nonuniform distribution of data, while CLV has nonuniform rotational speed.

Car seats

Many car seats have a variety of facing material. For example, while the main material may be leather for comfort and durability, there may be inserts of suede-like Alcantara which is relatively grippy and holds its occupant better during turns. Many seats also be partially covered in vinyl made to look similar to leather in areas where the occupant is unlikely to notice, like seat backs, to save cost.

Word to the wise, when a car brochure mentions “leather seating surfaces” as opposed to just “leather seats” they are subtly indicating that only where the body touches the seat is leather and the remainder is likely vinyl.

It has layers

Typical home construction includes an exterior cladding (brick, siding) then plywood attached to studs, between which there is insulation, then vapour barrier and then drywall and paint.

A winter coat will have a water- and wind-resistant shell and then a woolly layer to trap air as an insulator, then another layer to provide a smooth surface against indoor clothes.

A car’s metal will be painted with primer, then one or more layers of paint and clear coat.


Local quality can be confused with Principle 5 – Merging. If you modify portions of an object or service to better accomplish its intended purpose, making it less homogenous, then this is Local Quality.

However, if you connect two otherwise distinct objects or services into one, such as a pencil with an eraser on its end, this is Merging.

More examples

As I stumble across real world examples of this Inventive Principle in action I add them here.

Your turn

What problems do you face that this inventive principle could help solve? Have you used this principle before?