Thus, your
hypothesis predicts that if we observe a group of preschool children, we should
see that those who watch more television violence are more aggressive than those
who watch less television violence. Before we can evaluate this prediction, however,
we need to determine how we will distinguish between more and less television
violence, and distinguish between more and less aggression. Specifically,
we must decide exactly how we will define and measure television violence, and
exactly how we will define and measure aggressive behavior. The variables identifi
ed in the research hypothesis must be defined in a manner that makes it possible
to measure them by some form of empirical observation. These decisions
are usually made after reviewing previous research and determining how other
researchers have defined and measured their variables.