d: scientific precision, neatness, and simplicity

aha - reading this six (!) years later...  I'm pleased to find it still holds

An elegant solution may solve multiple problems at once, especially problems not thought to be inter-related.

d: scientific precision, neatness, and simplicity <the elegance of a mathematical proof>

One should have a "stretch goal"...

One should have a "stretch goal", shouldn't one? I like this definition:  In engineering, a solution may be considered elegant if it uses a non-obvious method to produce a solution which is highly effective and simple. An elegant solution may solve multiple problems at once, especially problems not thought to be inter-related.

Merriam-Webster Definition of ELEGANCE

1

a: refined grace or dignified propriety : urbanity   

b: tasteful richness of design or ornamentation <the sumptuous elegance of the furnishings>   

c: dignified gracefulness or restrained beauty of style : polish <the essay is marked by lucidity, wit, and elegance>   

d: scientific precision, neatness, and simplicity <the elegance of a mathematical proof>

source:  http://www.merriam-webster.com/dictionary/elegance

So - what's your stretch goal?