All the chewy goodness of fallacious reasoning in new fun-sized bites!
Ad verecundiam is Latin for “appeals to authority”
Ad populum is Lating for “appeals to the people”
An “appeals to authority” argument, according to Dr. John Nolt et al., occurs when “we accept or reject a claim merely because of the prestige, status, or respect we accord its proponents (or opponents).” In other words, if someone we hold in high regard says something, we immediately believe it.
Richard Dawkins says no one should believe God exists.
Therefore, I should not believe God exists.
Just because someone holds an impressive rank for particular achievements does not mean they get to make assertions with no evidence to support them. Do not be persuaded by titles. Be persuaded by good arguments.
An argument that “appeals to the people” principally follows the same structure of the “appeals to authority” except, in this instance, “we infer a conclusion on the grounds that most people accept it.”
97% of scientists agree with evolution
Therefore, I agree with evolution
This is a combination of both an appeal to authority (i.e. scientists) and most people (i.e. 97%). This statement only tells you about the quantity of something not whether a proposition should be believed based on any evidence. Again, do not be persuaded by how many people believe something. Be persuaded by good arguments.
The best way to point out someone’s fallacy is by using the Columbo tactic as laid out in the Funsized Tactics series. There are plenty of excellent resources available in book, e-book, or PDF format. Two good places to start, with regard to formal and informal fallacies, are A Preface to Philosophy by Mark B. Woodhouse and Schaum’s Outlines: Logic by John Nolt, Dennis Rohatyn, and Achille Varzi.
 John Nolt, Dennis Rohatyn, and Achille Varzi, Schaum’s Outlines: Logic, 2nd ed. (New York: The McGraw-Hill Companies, 2011), 199.
 Ibid, 201.