I am giving a single reference point for CR Prep Summary so that we can revise from a single page :
Strategies for Strengthen and Weaken Questions Summary
Strengthen and Weaken questions typically make up over half of the Critical Reasoning questions that you will see on the GMAT. Therefore it is important that you are familiar with the important strategies summarized below:
• Properly categorize the question using the question stem, making particularly sure that you do not confuse a Strengthen question with an Inference question.
• After deciding that the question type is Strengthen or Weaken, read the argument carefully and isolate the conclusion. Note any gaps or common logical fallacies within the argument.
• Make sure that you are very specific with the conclusion. The correct answer must strengthen or weaken the exact conclusion, not what you think the conclusion is about! Be careful not to “hijack” the conclusion.
• If it is a Strengthen question, consider what piece of information would fill the gap or remove any flaw within the argument. If it is a Weaken question, consider what piece of information would expose or create a flaw within the existing argument.
• After you have read the argument, carefully isolated the exact conclusion, and tried to anticipate the correct answer, look at each answer choice. Pick the one that provides a new piece of information (do not pick a “repackaged premise” from the original argument) that either strengthens or weakens the conclusion.
• Remember that on almost every Strengthen question, at least one of the answer choices will instead weaken the conclusion, and on almost every Weaken question, at least one of the answer choices will instead strengthen the conclusion. This is particularly true when there is confusing negation in the argument. Make sure you are picking the answer choice that follows the goal of the question stem.
Inference Strategies Summary
While not as common as Strengthen and Weaken questions, Inference questions are nearly certain to show up multiple times on your GMAT exam. To succeed with Inference questions, remember these three critical themes:
• Make sure that you properly categorize Inference questions. It is easy to confuse them with Strengthen questions.
• Correct answer choices on Inference questions must be true. Regardless of how the question stem is worded, once you determine that the question is asking for a conclusion, make sure the conclusion you pick must be true.
• Scope is the key to success on Inference questions. Incorrect answer choices always go a little too far—that is, they go outside what can be guaranteed from the information in the stimulus. Be wary of broad, categorical statements that seem reasonable but are not supported by the information in the stimulus.
Method of Reasoning Strategies Summary
To succeed with Method of Reasoning questions, remember the following:
• Method of Reasoning questions are easy to categorize. If the answer choices are describing argument structure or anything is boldface in the stimulus, you know you are dealing with a Method of Reasoning question.
• Boldface questions are the most common type of Method of Reasoning questions.
• Success on Method of Reasoning questions hinges on your ability to:
1. Understand the argument and properly identify the conclusion (or multiple conclusions), premises, and contextual information in the stimulus.
2. Pick the answer choice that is accurately describing the boldface sections. Often the differences in these descriptions are very subtle, but remember that only one answer choice can be correct. Look very carefully at the differences in wording, and figure out what makes one answer choice correct and the other incorrect.
• Your ability to use the “why?” test and properly isolate conclusions is particularly important on Method of Reasoning questions.
Strategies for Subtypes and Advanced Applications Summary
While the strategies for these subtypes are essentially the same as for their broader category, there are a few important differences to consider.
Plan/Strategy
• The objective of the plan takes the place of the conclusion.
• If it is a Weaken question, make sure you are actually weakening the plan, not simply considering what could make it better.
Useful to Evaluate
• These questions are best thought of as Weaken questions. Find the flaw in the argument and you will be able to figure out what missing information is required to better evaluate it.
• Most of these involve the common logical fallacies. Be particular wary of any questionable conclusions formed from data.
Explain the Paradox
• Instead of isolating a conclusion, you must isolate an apparent paradox or contradiction.
• Make sure the answer you pick is new information that completely resolves the apparent paradox.
Assumption
• Assumption questions are very common and generally a difficult type for students.
• The Assumption Negation Technique is particularly helpful in dealing with negatively worded answer choices.
• Remember: These are just Strengthen questions, but usually the correct answer is not advancing the argument but rather removing a flaw or possibility that would break down the argument.
Mimic the Reasoning
• Focus on argument structure, not content.
• The correct answer choice must contain the same logic, but the premises and conclusions do not need to be presented in the same order as the original.
• Any negation needs to be mimicked in the correct answer choice.