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