Critical Thinking notes

MDCAT Analytical and Logical Reasoning

Critical thinking is the careful analysis of statements, evidence, assumptions, arguments, patterns and conclusions. It requires separating what is definitely true from what is only possible, identifying weak or strong arguments, and avoiding conclusions that are not supported by the given information.

Meaning and Process of Critical Thinking

Critical thinking means examining information logically before accepting or rejecting it. In analytical reasoning, every answer must be based on the wording of the question and the evidence provided, not on personal guesses or outside assumptions.

A useful method is to read the statement carefully, identify its main claim, check the evidence, and then compare each option with the exact information given. A conclusion is accepted only when it follows with certainty or is clearly supported by the statement.

Fact means information that can be verified or is directly given in the passage.
Opinion means a personal belief, judgment or preference. It may not be proved true or false from the statement alone.
Inference is a conclusion reached from given facts or statements.
Assumption is an unstated idea that must be accepted for an argument or statement to make sense.
Do not add information from personal knowledge unless the question asks for general knowledge.
Words such as all, always, only, never and definitely make a conclusion very strong and therefore require strong evidence.
Words such as some, may, can, often and usually allow a less certain conclusion.

Statements, Conclusions and Inferences

A statement gives information. A conclusion is an idea claimed to follow from one or more statements. To test a conclusion, ask whether it must be true if the statements are true. If it is merely possible, it cannot be called a definite conclusion.

For example, Pakistan is a multilingual country and Urdu is the national language of Pakistan. These statements do not prove that all Pakistanis should learn many languages. They also do not prove any additional conclusion that is not supplied in the question. Therefore, neither conclusion is followed when the evidence is insufficient.

A conclusion follows when it can be drawn directly and definitely from the statements.
A conclusion does not follow when it is only a possibility, recommendation or personal opinion.
A national language does not mean that every citizen speaks only that language.
The statement that a country is multilingual does not prove that all citizens should learn many languages.
Use only the facts provided in the question while judging a conclusion.
If two conclusions are listed, test each one separately.
Possible, desirable and necessary are different ideas. A statement showing possibility does not prove necessity.

Inferences from Short Passages

Inference questions provide a short passage, often about a social or economic issue, followed by possible inferences. The task is to understand the passage and decide whether the inference is definitely true, probably true, definitely false or unsupported by the data.

An inference is definitely true when the passage directly proves it. It is definitely false when it contradicts the passage. If the passage does not contain enough information, the correct judgment is data inadequate. Do not treat silence as proof.

Definitely true means the inference must be correct on the basis of the passage.
Definitely false means the inference conflicts with a fact or condition in the passage.
Data inadequate means the passage does not provide enough evidence to decide.
A conclusion can be reasonable but still not be definitely proved.
A statement such as recycling awareness campaigns were launched supports the inference that a lack of awareness was perceived or suspected.
A statement such as watching documentaries increases awareness supports the inference that documentaries can lead to learning new information.
Do not assume the size, cause or result of a social problem unless the passage gives that information.

Assumptions and Implicit Ideas

An assumption is an unstated belief on which a statement or argument depends. To identify it, imagine that the assumption is false. If the original statement then loses its meaning or purpose, the assumption is implicit.

Consider the statement: Without reforming the entire administrative system, we cannot eradicate corruption and prejudice from society. It assumes that the administrative system can be reformed. It does not assume that corruption and prejudice are good. Therefore, only the assumption about the flexibility or possibility of reform is implicit.

An assumption is not directly written but is necessary for the statement to work.
An assumption must be relevant to the argument.
A statement about removing a problem does not imply that the problem is good.
The phrase without X, Y cannot happen usually assumes that X is necessary for Y.
To test an assumption, use the negation test: suppose it is not true and see whether the argument collapses.
Only assumption I, only assumption II, both assumptions and neither assumption are common answer forms.
An assumption is different from a conclusion because the assumption supports the statement, while the conclusion is derived from it.

Arguments: Strength and Weakness

An argument contains a claim and one or more reasons. A strong argument is relevant, practical, directly related to the issue and supported by reasonable evidence. A weak argument is emotional, vague, extreme, irrelevant or based on an unsupported belief.

For the issue of whether admission to professional degrees should be based only on merit, an argument that merit improves the quality of professional institutes is relevant. If another argument also gives a relevant and logical reason, both arguments may be strong. The strength depends on relevance and reasoning, not on the word yes or no.

A strong argument directly addresses the issue being discussed.
A weak argument may be true in another context but irrelevant to the question.
An argument that STEM fields drive the economy weakens the claim that art education should be prioritized because it gives a competing economic reason.
Emotional language alone does not make an argument strong.
Arguments based on practical consequences are usually stronger than unsupported personal preferences.
A strong argument should be general enough to apply to the issue, but not so broad that it becomes vague.
When two arguments independently support the same side and are relevant, both may be strong.

Cause, Effect and Evidence

Critical thinking requires separating a cause from an effect. A cause produces or contributes to an event. An effect is the result. A statement may show that two events are related, but it does not always prove that one caused the other.

Evidence must be connected to the claim. For example, launching recycling awareness campaigns indicates that authorities or organisations perceived a lack of awareness. It does not prove that every person was unaware or that the campaigns were successful.

Cause answers the question why something happened.
Effect answers the question what happened as a result.
Correlation means two events are related, but it does not automatically prove causation.
The inference that documentaries can lead to learning new information is supported by the statement that they increase awareness.
A campaign being launched proves an intended response, not necessarily its success.
Use the exact strength of the evidence. Do not change may into must or some into all.
Evidence should be relevant, sufficient and free from contradiction.

Classification, Odd One Out and Number Patterns

Classification questions ask you to identify the item that does not follow the common rule. First, inspect category, use, shape, spelling, number properties and relationships. The odd item is the one that cannot follow the same rule as the remaining items.

For word questions, count letters, vowels and consonants exactly. A five-letter word with exactly two vowels and consonants at both ends has a consonant as its first and last letter. In the given group, Plant is different because it contains only one vowel, a, while it has five letters and consonants at both ends.

Rabbit is the odd one out among three birds because rabbit is a mammal, not a bird.
For letter patterns, check total letters, vowels, consonants and the first and last letters.
Plant has five letters, one vowel and consonants at both ends, so it does not meet the rule of exactly two vowels.
In number patterns, test common operations such as addition, subtraction, multiplication, division, squares and digit sums.
Check the same rule against every item before selecting an odd number.
If 34 is the answer, identify the property shared by the other numbers and show why 34 fails it.
Do not select an item merely because it looks unusual. Prove that it breaks the common rule.

Ordering and Comparative Reasoning

Comparative statements can be arranged from greatest to least or least to greatest. Convert every statement into a clear order before checking the conclusion.

For example, blueberries cost more than strawberries, and blueberries cost less than raspberries. The order is raspberries greater than blueberries greater than strawberries. Therefore, the statement that raspberries cost more than both strawberries and blueberries is true.

More than means greater than. Less than means smaller than.
If A is greater than B and B is greater than C, then A is greater than C.
A chain of comparisons can be combined only when the relationships are clear.
The order raspberries, blueberries, strawberries follows from the two given comparisons.
Check whether the third statement repeats or correctly combines the first two statements.
Do not reverse an inequality. If A is less than B, B is greater than A.
When information does not compare two items directly or indirectly, their relative order is undetermined.

Opinion and Self-Assessment Statements

Some reasoning questions present personal statements such as I value my independence and freedom, I handle stress well, or I am comfortable with who I am. These questions test whether the selected response matches the meaning of the statement and remains consistent with the person's overall responses.

Options may include yes or no, agree or disagree, and strongly agree. A student should select the option that honestly represents the statement. In a set where positive self-description is required by the intended response, examples include yes for enjoying intellectual discussions, making decisions quickly, trying unfamiliar experiences, being punctual and being the life of the party, and strongly agree for independence, self-comfort and handling stress well.

Read the statement as a complete sentence before choosing an option.
Yes and no are suitable for direct questions such as Do you enjoy trying new experiences?
Agree or strongly agree are suitable for statements such as I value my independence and freedom.
Keep answers consistent. A person who claims to handle stress well should not usually select an opposite response to a similar statement.
There is no logical proof for a personal preference in the same way that there is proof for a number pattern.
Do not confuse being punctual with being busy, or independence with refusing all help.
Answer self-assessment items according to the meaning of the statement, not according to an unrelated personal quality.

General Knowledge in Reasoning Questions

Some analytical reasoning sets include direct factual questions. These require recall rather than deduction. Read the wording carefully, especially terms such as first, national, year and Ghazwa.

The listed facts include Islamic history, Pakistan history and religious knowledge. These facts should be kept separate from inference rules because a factual question has a specific correct answer, while an inference question depends only on supplied statements.

Prophet Sulaiman (A.S) was able to communicate with animals and jinn by Allah's permission.
The First Indo-Pakistan War was fought in 1947.
The first Ghazwa of Islam was Ghazwa Abwa.
The word first requires the earliest event in the stated sequence.
A direct fact should not be changed into a broad conclusion unless the question asks for an inference.
In religious questions, use the accepted names and respectful form given in the syllabus.
Distinguish historical recall from logical deduction before solving the question.

Key terms

Critical thinking: The process of analysing information logically before accepting a claim or conclusion.
Statement: A sentence or group of words that gives information or makes a claim.
Conclusion: An idea that is claimed to follow from one or more statements.
Inference: A conclusion reached from evidence or information in a passage.
Assumption: An unstated idea on which a statement or argument depends.
Argument: A claim supported by one or more reasons.
Strong argument: A relevant, practical and logically supported reason for a claim.
Weak argument: A reason that is irrelevant, unsupported, emotional or logically insufficient.
Evidence: Information used to support or evaluate a claim.
Definitely true: A judgment that must be correct according to the given information.
Definitely false: A judgment that contradicts the given information.
Data inadequate: A judgment used when the passage does not provide enough evidence.
Cause: An event or condition that produces or contributes to another event.
Effect: The result produced by a cause.
Correlation: A relationship between events that does not by itself prove causation.
Classification: Grouping items according to a shared rule or property.
Odd one out: The item that does not follow the common property of the remaining items.
Comparative reasoning: Using relationships such as greater than or less than to arrange items or test a conclusion.

Test yourself on Critical Thinking

Free Critical Thinking MCQs with an explanation on every answer. No account needed.

Practise Critical Thinking MCQs

One page notes

The whole chapter on one page, for the last days before the exam.

Critical Thinking One Page Notes

Opinion Statements

Opinion questions ask for your personal preference, tendency, or quality.
Choose the option matching your honest view; do not treat personal opinions as factual conclusions.
Common qualities include independence, detail orientation, openness, social preference, and future concern.
Agree or disagree consistently with the exact wording of the statement.

Arguments and Conclusions

An argument contains premises and a conclusion supported by those premises.
A conclusion is supported only when premises are true and logically lead to it.
A conclusion may explain an observed result, but correlation alone does not prove causation.
Reject conclusions introducing information, recommendations, or assumptions absent from the statement.
For arguments, judge relevance, truth, logic, and adequacy of supporting evidence.

Strengthen and Weaken

A strengthening statement provides evidence making the conclusion more likely.
A weakening statement provides evidence reducing the conclusion's probability or exposing an exception.
For cause-and-effect claims, consider alternative causes, opposite evidence, and whether the effect actually follows.
A relevant comparison can weaken a broad claim, such as older phones having better battery life.
Evidence supporting better sleep strengthens delaying school start times.

Inference and Deduction

Definitely true follows directly and certainly from the passage.
Definitely false contradicts information given in the passage.
Do not use outside knowledge unless the question requires ordinary logical meaning.
A universal statement applies to every member of the stated group.
If all hospital doctors attended and Dr Ahsan did not, Dr Ahsan is not a hospital doctor.

Assumptions and Fallacies

An assumption is an unstated idea required for an argument to make sense.
A privacy-right argument assumes personal privacy is threatened or needs protection.
A false dilemma presents only two choices while ignoring other possible alternatives.
Either budget cuts or project failure is a false dilemma if raising funds is possible.
Separate strong arguments from weak claims, irrelevant reasons, and unsupported generalisations.

Statements and Relationships

An opinion expresses judgment or preference, such as calling chocolate the best flavour.
A fact can be checked as true or false; an opinion depends on personal judgment.
Essential parts are indispensable: a city cannot exist without residents.
Always-associated words show necessary relationships; books necessarily contain pages.
A survey percentage describes its surveyed group and supports conclusions within that group.
No conclusion follows when proposed actions are recommendations rather than logical results.

Must remember

Personal-preference questions have no universal answer; select the response matching your view.
Strongening adds relevant support; weakening adds relevant doubt.
Correlation does not automatically prove causation.
Definitely true must follow completely from the passage.
Definitely false must conflict with the passage.
An assumption is necessary but unstated.
False dilemma ignores additional choices.
A conclusion must be logically supported by true premises.
Survey results apply carefully to the stated population.
Recommendations do not automatically follow from facts.

Analytical and Logical Reasoning shortcuts

Choosing the stronger supporting argument

Choose the option that directly explains why the claim is true. Prefer relevant evidence with a clear link to the claim, not a statement that is merely related.

Identify the claim and ask, “Why would this make the claim true?”
Reject personal opinions, unrelated facts and extreme statements.
Example: “Teachers should be paid more” is supported by “They shape future generations.”

This shortcut does not apply when the option gives direct statistical or experimental evidence that is stronger than a general reason.

Finding the pattern in letter and number series

Check letters and numbers separately. Look for equal increases, alternating changes, multiplication, or a repeating pattern.

Convert letters to positions if needed, such as A = 1 and D = 4.
Find the change in the letters and in the numbers independently.
Example: A2, D4, G6, J8 has letters increasing by 3 and numbers by 2, so the answer is M10.

Do not assume a simple addition pattern if alternating or multiplication patterns fit all the given terms.

15 more Analytical and Logical Reasoning shortcuts are in the MDCAT pack. Already have it? See all shortcuts