The Four Weighing Mechanisms
Magnitude, probability, timeframe, and scope are the four standard tools PF debaters use to compare impacts. You will be able to apply each mechanism to compare two competing impacts.
Magnitude and Scope
Magnitude compares how severe an impact is (a small economic dip vs. a recession), while scope compares how many people are affected (a policy affecting a single industry vs. one affecting the entire national workforce). These are often confused, but they answer different questions: magnitude asks 'how bad,' scope asks 'how many.'
Probability and Timeframe
Probability asks how likely an impact actually is to occur given the evidence (a near-certain outcome vs. a speculative worst-case scenario), while timeframe asks how soon the impact happens (an immediate harm vs. one that might occur decades from now). A common weighing move is arguing your impact should come first because it is both more probable and happens sooner, even if the opponent's hypothetical impact is larger in magnitude.
Pro argues a policy prevents a rare but catastrophic event; Con argues an opposing policy causes a smaller but near-certain harm.
Con's weighing: 'Pro's catastrophic scenario is high magnitude, but their own evidence puts the probability below 2% and the timeframe decades out. Our harm is smaller in magnitude, but it is happening right now with near certainty, to millions of people today — you should weigh probability and timeframe over a speculative, low-likelihood magnitude claim.' This directly names and applies multiple weighing mechanisms.
1. Which weighing mechanism asks 'how many people are affected'?
Answer all 1 to check.
Use magnitude, scope, probability, and timeframe by name to give the judge concrete comparison tools.