In the 1800s, studies of eye movement were made using direct observations.

Then, they use observation and mathematics to find the answers.

Teachers can use a checklist and observation to assess student success with the particular material.

Most psychological research uses observation with some component of intervention.

Researchers also use direct observations, work sample analyses, and focused case studies.

It used social observation as its means to do so, going away from statistical information that had been previously preferred.

However, apart from using empirical observations like those shown in Figs.

The research will obtain case-study data using observation and interviews.

The relative motion can be achieved by using airborne observations in aircraft, for example.

Experimentation is using measurements and observations to learn something.