<span>an action such as a prolonged speech that obstructs progress in a legislative assembly while not technically contravening the required procedures.</span>
I believe the answer is: Bias the sample
Convenient timing and biased title would most likely make the study to appeal to a specific segment of population, which could make a the sample become biased.
For example, researchers could make the majority of their subjects to be younger in age if they conveniently timed the study in the middle of the night, when most middle aged and older people are already asleep.
