Manber and others at Google have tested our experiences of search, and found that nearly imperceptible improvements in speed affect the way we feel not just about the service, but also about the quality of the results.

FORBES: Magazine Article

If you change your focus from near to far, the shift in light quality is almost imperceptible.

WSJ: The Petzl Nao: A Smarter Light | At Play

But because these savings came not from giant plants but in zillions of tiny pieces imperceptible to the untrained eye, energy efficiency gets little respect.

FORBES: Magazine Article

After all, loyal fans of blended Scotch whiskies, which are made differently every year but are always supposed to taste exactly the same, often complain often over seemingly imperceptible changes, and even changes in the water used.

FORBES: Whiskey Or Water? Marketing Nightmare As Bourbon Fans Incensed Over Choice

Movement in the Alvord is so slight as to be almost imperceptible--sand dunes on its eastern side are shifting.

FORBES: A Desert Where?

Demonetized gold will fluctuate in a far more volatile manner than the organic, almost imperceptible, waves that mark the gold standard.

FORBES: The Gold Standard: A Litmus Test For GOP Candidates

So what happens at Bali matters, though the declaration that comes out of it will be encrypted in diplomatic language, and the difference between success and failure will be imperceptible to the untrained eye.

ECONOMIST: Climate change