Logical Reasoning Flashcards
What two ways can the necessary or sufficient conditions be linked in a sufficient assumption question?
1) Evidence: D->E
Conclusion: D->F
Sufficient assumption: E->F
2) Evidence: A->B
Conclusion: C->B
Sufficient assumption: C->AWhat are the three common sufficient assumption formulas?
1) Restatement or broadening of argument /conclusion
2) Contrapositive of argument/conclusion
3) Linking of necessary or sufficient conditions
What is the 5 step approach to logical reasoning questions?
1) Identify question type by reading QUESTION STEM
2) Determine whether stimulus contains fact set or argument
3) if FACT SET - try to make connections between parts
4) if ARGUMENT - determine reasonability of argument
5) Pre-phrase answer or start by eliminating answer choices
What are some evidence indicator words?
Because, follows, for, since, the reason being
What are some conclusion indicator words?
As such, consequently, demonstrates, establishes, hence, it follows that, so, thus, therefore
What are some sufficient condition (before arrow) indicator words?
All, any, each, every, if, in order to, people who, the only, to be, when, whenever
What are some necessary condition (after arrow) indicator words?
Depends upon, must, only, only if, only when, only where, requires, then, until
What is the unless/except/until/without formula?
Take “unless” or similar word as introducing the necessary condition, negate other part of sentence to make it the sufficient condition
“No X unless Y” = If X -> Y
What is the quantity value of “all”?
100%
What is the quantity value of “most/often/usually”?
More than half. Potentially 100%
What is the quantity value of “several/many”?
More than 2. Potentially 100%
What is the quantity value of “some”?
At least 1. Potentially 100%
What is the quantity value of “few”?
At least 2, context dependent
What is the quantity value of “none”?
0
What are some examples of extreme language (and more likely to be wrong in inference questions)?
All, always, definitely, every, never, none, only
What are some examples of moderate language (and more likely to be correct in inference questions)?
Maybe, not all, not always, not every, perhaps, possibly, some, sometimes
What are two ways of evaluating an argument’s validity?
Invalid argument often:
1) overgeneralize based upon insufficient evidence (draw too strong a conclusion from weak evidence)
2) Fail to consider alternate causes/explanations/possibilities (assume potential cause is THE cause)
How does one identify a necessary assumption question?
“Assumption” with words such as “depends upon”, “requires”, “assumes”, “presupposes”
Eg “Which one of the following is an assumption upon which the argument depends?”
How does one identify a sufficient assumption question?
“Assumption” with words such as “allows”, “enables”, “follows logically/is properly inferred…if assumed”
How does one identify a strengthen question?
“Strengthen”, “most strongly supports”, “most justifies”, “most helps to justify”, “additional support”
Eg “which one of the following, if true, most helps to strengthen the argument?”
How does one identify a necessary weaken question?
“Weaken”, “call into question”, strongest logical counter”, “undermine”, “cast doubt”, “incomplete”
How does one identify a flaw question?
Words such as flaw, error, vulnerable to criticism, questionable, fallacious, unwarranted, weakness
Eg “The argument is vulnerable to criticisms on the grounds that if”
How does one identify an evaluate the argument question?
Eg “Which one of the following would be most useful to know in evaluating the argument?”
How does one identify a method of reasoning question?
Words such as “method of reasoning”, “argument proceeds by”, “responds…by”, “employs…strategies/techniques”
E.g. “The argument employs which of the following reasoning techniques?”
