Key Takeaways
- Arguments consist of claims, evidence, and reasoning connecting them
- Strong evidence is relevant, sufficient, credible, current, and verifiable
- Common fallacies include ad hominem, hasty generalization, and false dilemma
- Facts can be verified; opinions are subjective judgments
- Bias is indicated by emotional language, one-sided presentation, and omitted evidence
Last updated: January 2026
Evaluating Arguments and Evidence
The TEAS tests your ability to analyze the strength of arguments and evaluate whether evidence adequately supports claims. These critical thinking skills are essential for evaluating medical research and patient information.
Components of an Argument
| Component | Definition | Example |
|---|---|---|
| Claim | The main point the author wants you to accept | "Hand sanitizers should be mandatory in all hospitals" |
| Evidence | Facts, data, or examples supporting the claim | "Studies show 40% reduction in infections when sanitizers are available" |
| Reasoning | The logical connection between evidence and claim | "Since sanitizers reduce infections and infections harm patients, they should be required" |
| Counterargument | Acknowledgment of opposing views | "Some argue alcohol-based products cause skin irritation..." |
| Rebuttal | Response to the counterargument | "...however, new formulations have addressed this concern" |
Types of Evidence
| Type | Description | Strength |
|---|---|---|
| Statistical data | Numbers from research or surveys | Strong if from reliable source |
| Expert opinion | Views from qualified authorities | Strong if expert is credible |
| Anecdotal evidence | Personal stories or examples | Weak—not generalizable |
| Research studies | Formal scientific investigations | Strong if peer-reviewed |
| Logical reasoning | Deductive or inductive arguments | Varies by validity |
Evaluating Evidence Quality
Questions to Ask:
- Is it relevant? Does it directly support the claim?
- Is it sufficient? Is there enough evidence?
- Is it credible? Is the source reliable and unbiased?
- Is it current? Is the information up-to-date?
- Is it verifiable? Can it be confirmed by other sources?
Logical Fallacies
Logical fallacies are errors in reasoning that weaken arguments. Recognizing them helps you evaluate arguments critically.
| Fallacy | Description | Example |
|---|---|---|
| Ad hominem | Attacking the person, not the argument | "You can't trust his research—he's not even a real doctor" |
| Hasty generalization | Conclusion from too little evidence | "Two patients recovered quickly, so this treatment works" |
| False cause | Assuming causation from correlation | "Crime increased after the law passed, so the law caused crime" |
| Appeal to authority | Citing unqualified experts | "A famous actor says vaccines are harmful" |
| False dilemma | Presenting only two options when more exist | "Either you support this bill or you don't care about patients" |
| Circular reasoning | Using the claim as evidence for itself | "This treatment is best because it's superior to others" |
| Straw man | Misrepresenting an opponent's argument | "They want to reduce costs, so they must not care about quality" |
| Bandwagon | Claiming something is true because many believe it | "Most people agree, so it must be correct" |
Bias in Writing
Bias is a preference or prejudice that affects objectivity.
Signs of Bias:
- Loaded or emotional language
- One-sided presentation of issues
- Omission of contradictory evidence
- Unsubstantiated opinions stated as facts
- Personal attacks on opposing viewpoints
Fact vs. Opinion
| Fact | Opinion |
|---|---|
| Can be verified | Cannot be proven true/false |
| Objective | Subjective |
| "The normal body temperature is 98.6°F" | "This is the best hospital in the state" |
| Based on evidence | Based on belief or feeling |
| Uses neutral language | Uses evaluative language (best, worst, should) |
TEAS Strategy for Argument Questions
- Identify the claim - What is the author trying to prove?
- Find the evidence - What support is provided?
- Evaluate the connection - Does the evidence actually support the claim?
- Look for weaknesses - Are there fallacies, bias, or missing evidence?
- Consider alternatives - Could the evidence support a different conclusion?
Test Your Knowledge
Which type of evidence is generally considered the weakest for supporting a scientific claim?
A
B
C
D
Test Your Knowledge
"If you don't support increasing hospital funding, you obviously don't care about patient safety." What logical fallacy does this represent?
A
B
C
D
Test Your Knowledge
Which statement is a fact rather than an opinion?
A
B
C
D