A decade later, such intensive, firsthand observation was not an option.

From my firsthand observation, I would have to say that it more than did the job.

"I can still learn a great deal from firsthand observation of whatever's left."

What can you say about Chicago, based upon your firsthand observations and now from a distance?

After all, they had no firsthand observations to go on.

One based on firsthand observations, including my own, that makes it look as though Lawrence is losing his grip.

There were his firsthand observations from his time on their planet.

"To be certain, we must enter the cloud and conduct firsthand observations."

Without firsthand observation, I cannot be more specific than that.

But I also went out with the candidates and made my own firsthand observations.