Each observer could use radar to say where and when an event took place by sending out a pulse of light or radio waves.

This adds to the total sum of knowledge that the observer can use to make decisions.

In decades past, observers used to debate whether golfers were even athletes.

When a seizure occurs, an observer can use common sense to prevent injuries.

The observer would first use this device to measure the angular width of the target.

Numerous political observers and journalists have used the term when describing or commenting on the 2007-2012 global financial crisis.

Using this form of extraction, observers can use a light microscope when examining the results.

The main advantage is that the observer can use both eyes instead of only one.

Note that the observer should use slopes expressed as a percent.

In order to monitor aircraft, observers used a simple but effective mechanical tracking device.