Research is a way to define problems and evaluate solutions, it makes sure all PR efforts are strategic because it allows PR to base its decisions on measurable data, which is another way research helps. It allows to show measurable results.
In short, research provides the information required to understand the needs of the public and develop powerful messages that resonate with the audience.
Without research, PR would be following "hunches" and "gut feelings" to create publicity. Research is the strategic foundation of modern public relations management.
Thoughts?