However, patients responding to such advertisements may differ from patients not responding which leads to selection bias and hampers external validity.
–How do radio, print and television advertisements differ in who they reach and how?
The techniques differ from the conventional pop-up advertisements, as when the travel company Orbitz.com pays publishers to have its ads pop up on readers' screens.
The survey findings are significant because industry executives are frantically searching for ways to forge more emotional connections with fractious, and fractionated, consumers that differ from conventional methods like running 30-second television commercials and print advertisements.
Poltergeists differ from mediums.
The Beacons differ from Snowdonia differ from the Cambrian Mountains differ from the Preselis.
How does selling furniture differ from journalism?
How did it differ from home?
How does it differ from the budget?
How do these differ from news conferences?
