Human Anatomy & Physiology (Human Body Systems)

Unit 2: Unit 2: Communication (Nervous & Endocrine)HBS 2.2Human Body Systems: research methods

Read scientific literature

Find the claim, find the evidence, and judge how strong the study really is.

Builds on (2 levels back)inferred · high confidence

Claim vs. evidence: Reading a paper means separating what the authors say from the data that backs it up.
Reading a simple data table: Evidence in a paper is usually numbers in a table or figure you have to read correctly.

Prerequisites are inferred: pending teacher review.

Re-learn the skill with worked practice and clear examples.

Use the abstract, methods, and results to find the claim and its evidence, then judge strength using sample size and whether a control group was used.

Step 1: Know the sections

The abstract is a short summary at the top, the methods section says exactly what the scientists did, and the results section holds the data.

Step 2: Separate claim from evidence

The claim is what the authors say is true; the evidence is the data in the results that supports it. A claim with no data behind it is just an opinion.

Step 3: Judge the strength

A study is stronger when it tested many subjects (a bigger sample size) and used a control group, because both make it harder for chance or other factors to explain the result.

Practice

Two papers test the same drug. Which study gives the stronger evidence?

Reviewed

Study	Subjects tested	Untreated comparison group?
Study 1	6	No
Study 2	400	Yes

A.Study 1, because fewer subjects is simpler
B.Study 2, because it has a larger sample size and a control group
C.They are equally strong
D.Study 1, because it has no comparison group

Show the worked solution ▾

Answer: B. Study 2, because it has a larger sample size and a control group

Step 1: Compare sample sizes: Study 2 tested 400 subjects versus only 6, so its result is less likely to be a fluke.
Step 2: Check for a control group: Study 2 also has an untreated comparison group, so it can show the drug, not something else, caused the change.

Why it's right: A bigger sample size plus a control group both reduce other explanations, so Study 2 gives the stronger evidence.

Why the others miss:

A: Fewer subjects is weaker, not stronger, evidence.
C: They differ in sample size and control group, so they are not equal.
D: Having no comparison group makes Study 1 weaker, not stronger.

Aligned to HBS 2.2: sample size and controls · reading level ~grade 9

Where you'd see this

When two news stories disagree, checking each study's sample size and control group tells you which to trust.

Careers that use this

Clinical Research Coordinator: Screens published studies, favoring ones with large samples and control groups before citing them.

Video library

Watch: Read scientific literature

How to Read a Scientific Paper Efficiently and Critically

Scientific Writing with Karen L. McKee · 15 min

Guided notes

Fill these in as you work through the lesson.

Big idea: A research article has a part that tells you what they did (methods), a part with the data (results), and a claim; your job is to separate the claim from the evidence and judge how strong it is.

Key terms: write the meaning

Abstract (the short summary at the top):
Methods (the section that says what they did):
Results (the section with the data):
Claim (what the authors say is true):
Sample size (how many were tested):

The rule

To read a paper, find the they make, find the that supports it, and remember that a bigger size and a group make the study stronger.

Check yourself

Which section of a paper tells you what the scientists actually did?
What is the difference between a claim and the evidence for it?
Why is a study of 500 people usually stronger than a study of 5?

Work one example

An abstract says: 'In 8 worms, the drug raised signaling speed, so the drug works in people.' Find the claim, find the evidence, and give two reasons to be cautious.