Back in my wanderin' days, I was hiking a federal trail outside Los Angeles. As I was walking along an arroyo -- a high ridge beside a dry stream bed -- I got a sudden urge.

"Jump."

I resisted. It was a hot, dry day. The stream bed was a good 8 feet down. The ground was rocky and uneven.

"Jump!"

I felt distinctly uneasy.

I jumped.

And as I dropped, I heard a high whizzing sound, a WHING!

In moments I was on the bottom of the wash, looking up at a puff of dirt rising from where I'd stood.

I popped my head up over the ridge. This time I heard the bang, too.

Somebody was shooting at me. Somebody was trying to kill me.

For the next, tense 20 minutes or so, I worked my way around the hill the shots were coming from, dodging more shots, eventually slipping down the brush to safety.

I never liked L.A.

Where did the urge to "jump!" come from? Weird coincidence? ESP? Divine intervention?

Here's what I think. I think somewhere in the back of my mind, I'd noticed something that didn't fit.

Probably, it was the glint of light on a gun barrel, high up in the dusty land. Somewhere, I registered that a man-made object was tracking me.

My unconscious mind decided that I was in danger, and it acted to save me.

And I'm grateful.

I remembered all this because of a book I'm reading called "Blink," by Malcolm Gladwell.

It's fascinating. There are numerous examples of people making instantaneous decisions that turn out to be right. There are art experts who glance at a scientifically tested "antique" sculpture, and immediately know it's a fake.

Elsewhere in the book, the author interviews psychologists who can predict within just a few minutes of watching them whether a couple will stay married. (What's the danger sign? When one spouse shows contempt for the other, however subtle.)

In yet another, students can watch a videoclip of a teacher -- with the sound turned off -- and again within a minute or two, say whether or not that teacher is any good.

Not all snap judgments are reliable. Plenty of research shows that sometimes a quick decision is informed more by prejudice than knowledge.

Sometimes, in a moment of great danger or stress, we seem to LOSE the ability to sum up a situation. The mechanism of "blink" judgments can be very effective -- but not necessarily so.

Here's another twist. Gladwell describes another situation in which doctors are fed more and more data about a patient. Then they get to change their earlier diagnoses.

What happens? The doctors' confidence in their judgment grows steadily. The accuracy of their diagnosis does not.

As a librarian, and as something of a technophile (my family has THREE networked home Internet stations) I am very much aware of the phenomenon best captured by the expression, "TMI!" Too much information.

We are the targets of ads, radio shows, TV, newspapers, Internet news feeds, cell phones, music, and even real live people, all clamoring for attention.

To make good decisions, we don't need MORE information. We need the RIGHT information.

Because you never know when you might have to move fast.