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BIOLOGY

Chapter 1 THE STUDY OF LIFESCIENTIFIC METHOD

Publish

Peer

reviewMake

observations

Ask a question

Consult prior

knowledge

Formulate

a hypothesis

Make

predictions

Collect and

interpret data

Draw

conclusions

Consult prior

knowledge

Scientific Method

Figure 1.6

Figure 1.11

a.

b.

•Observations•Questions

Scientific Method

Scientific Method

•Observations•Questions•Hypothesis

•Educated guess – why?•Background research•Testable & falsifiable •Tentative explanation•Null hypothesis = no difference•Alternative hypothesis

Which of these are testable hypotheses?

1. Increasing numbers of deformities such as the extra limbs that have been noted in many frog populations in North America are caused by infection by trematodes (parasitic flatworms).

2. People with strong religious beliefs live more meaningful lives.

3. People are more likely to survive cancer if they have a positive attitude.

4. Humans and chimpanzees diverged from a common ancestor that lived 5–7 million years ago.

5. Corn seedlings grow more quickly when people talk to them.

Scientific Method

• State the Ho:

• State the HA:

Scientific Method

•Observations•Questions•Hypothesis

•Educated guess – why?•Background research

•Tentative explanation•Predictions

•For experimental design•Deductive reasoning If …. Then

•General premise specific results predicted

Scientific Method

•Observations•Questions•Hypothesis•Predictions

•For experimental design•Experimentation

•Qualitative•Quantitative•Control grp•Experimental grp•Sample size

Group 1 Group 2

Experimental group:receives treatment

Control group:receives placebo

Observe or make measurements.

Are blood pressures lowerin the experimental group?

Compare results. Yes No

Hypothesis received support.

Modify hypothesis to fit the new findings.

large numberof appropriate subjects.

Randomly divide the subjects into two groups.

Treat the groups equallyin all ways but one.

Scientific Method

•Observations•Questions•Hypothesis•Predictions

•For experimental design•Experimentation•Analysis – statistics

•Chi square•Student t-test

•Paired or unpaired•Regression•ANOVA

Scientific Method

•Observations•Questions•Hypothesis•Predictions

•For experimental design•Experimentation•Analysis – statistics•Interpretation/Conclusion•Presentation

Publish

Peer

reviewMake

observations

Ask a question

Consult prior

knowledge

Formulate

a hypothesis

Make

predictions

Collect and

interpret data

Draw

conclusions

Consult prior

knowledge

Scientific Method