What is sampling bias?
From PsychWiki - A Collaborative Psychology Wiki
This bias occurs because of the sample selection and if certain members are equally balanced or objectively represented in the population. Sampling bias may occur any time the sample is not a random sample. This is important because sampling bias means that the data collected may not be accurate or represent the group.
Example / Application
Example: Stephen Colbert's Fancy Feast study
Application: The study on the distinction of dog food and pate conducted could have easily become bias by the sample chosen to participate. If participants who were avid pate lovers who were chosen for example, would bias the study because they might be able to distinguish the difference, creating an error or bias. Also, if the sample was just taken from wine economists or individuals pertaining to the association rather than a random sample, this as well will bias the study.