the (1 - 2 σ) design challenge

Have you ever wondered how size ranges are picked for products? Most of us don't think of it because we tend to "fit", but if you are outside the normal range - or if you have a friend who is - you tend to notice problems. 

Anthropometry studies fixed and dynamic human body dimensions - how easily can you reach the pedals on your car, can you adjust the radio comfortably, is your chair comfortable, etc, etc? It turns out some of our physical attributes follow normal distributions - look at enough of the population and you can predict what percentage are above or below some measurement. 

Standard deviation (σ) is a measure of the dispersion of a collection of measurements. If you have had a bit of statistics, you know it, otherwise it is convenient to note that about 68% of a normal distribution (bell shaped curve) is within one standard deviation of the mean and a bit over 95% is within two standard deviations. So (1 - 2 σ) of, say human height, would represent roughly 5% of the population that is very short or very tall. For products where height is important it turns out many of the products sold are designed for people in the range that starts with the 5th percentile of females and the 95th percentile of males. This turns out to be about two standard deviations.

  A friend turns out to be very tall - well above the 95th percentile for males and she happens to be female (she is in the 99.99 percentile for males). As you might imagine, many things just don't fit. If you get a desk, you need to have four bricks to lengthen the legs, if the seat in the old car doesn't go back far enough you cut and reweld the seat mounts, etc... 

Another tall (but not incredibly tall) friend noticed her back was killing her when she tried to prepare food. Her counter was too low and putting in new counters in the apartment wasn't practical. Her solution was to mount a chopping board on a small wooden cabinet to move the working position up by the difference between her height and that of the average female (which seems to be the target of her counter top design height).  She reports a fantastic improvement in comfort.  A neat solution that also maximizes counter space, but it is non-adjustable. 

I'm not a clever designer, but some of the readers of this blog are. There are good MIT, Stanford, Stevens, CMU, BYU and Utah people - and probably many others. I'd like to see a design for the misfits -- the (1 - 2 σ) population. 

The specific challenge is to design a variable height chopping board for the tall end of the curve - above the 95th percentile male height distribution.  While the number of women who might use a higher chopping board is small, the number of men is large - perhaps anyone over 6'0 or 6'2 could use such a gizmo.   (Perhaps this would remove an excuse that tall guys have for not cooking.)

Design a chopping board (or just the mount to attach a commercial board) that has the following characteristics:

• very stable under heavy chopping load  
• adjustable in height between 2" and 12" 
• potentially inexpensive 
• easy removal of the chopping board for cleaning
• aesthetically pleasing 

Keep the rights to the design - it would be extra cool if someone tried to make a product.  The potential market, given the size of the population, is non-trivial. 

The winner will be awarded one million tingilinde points, which have an approximate cash value of forty two cents. Email your designs by January 30, 2008 to esc (at) mac (dot) com. 

If you want to try something besides a cutting board, feel free. And products for the other size of the height distribution are good too.

(see the follow-on)

Comments

[Doug]

I'm left-handed, a small product market that diminishes further as aging lefties are killed by the right-handed design skew of products and infrastructure. Perhaps the very tall part of the population succumbs early too, all those low-hanging chandelier concussions and shower head lung punctures? Designs to keep these folks healthy and functional longer would extend their product-consuming lives!

[Trudy Johnson-Lenz]

In my mind's eye, I see a tabletop chrome stand with adjustable legs. At the top is a tray that holds a standard-sized cutting board. The whole apparatus can be easily moved out of the way and used for other storage.

Or maybe instead of the legs being adjustable, the shelves/tray are adjustable.

Here's a product that has some of the characteristics. Imagine this in a smaller, tabletop size, with telescoping legs and no drawer. The distance would vary between the top and bottom shelves as the legs were adjusted.

http://www.shoppingsquare.com.au/p_4267_Adjustable_Table_Top_Shelf_with_Drawer__Chrome_Steel

[marguerite manteau-rao]

Steve, what a great idea! I am going to tweet and forward to some of my friends from SJSU graduate art program - lots of clever craftsmen there.

[Jean]

Cooks like their boards. So, I'm thinking a mount would be preferred over a specialized board. Additionally, if such an adjustable mount could also double as a standing platform for short cooks, both ends of the height spectrum are better served.

[steve]

For people who stumble across this there has been progress. Basically the idea was that you need a working surface that is stable, relatively inexpensive and adjustable. After awhile it became clear you could have two, but not three of these. In the end adjustability was thrown out. It turns out that numerous studies have been made on the right height for food preparation for people of a wide range of sizes. Using that we found a manufacturer to make very sturdy raised wooden cutting boards - this one is very wide and serves as a raised counter.

Keeping with the idea of looking for other objects for someone who is very tall - Trek even built a special bicycle.