Biology Chapter 1

Front 1

Anecdotal evidence

Back 1

is an informal observation that has not been systematically tested.

e.g., You may notice that you feel more awake when you drink coffee, and it seems to help you concentrate as you stay all night awake to finish an assignment. Such informal, personal observations are called anecdotal evidence.

Front 2

scientific hypothesis

Back 2

a testable and falsifiable explanation (statement) for a scientific observation or question.

is testable if it can be supported or rejected by carefully designed experiments (experimentation) or non-experimental studies.

The information in peer-reviewed literature can be used to formulate a scientific hypothesis.

Front 3

An experiment

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is a carefully designed test, the results of which will either support or rule out a hypothesis.

Front 4

Peer review

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is a process in which independent scientific experts read scientific studies before their publication to ensure that the authors have appropriately designed and interpreted their study.

Front 5

The scientific method: (The six important steps)

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Observation
Question
Review peer reviewed studies
Hypothesis (hypotheses)
Experiments and data analyzing
Conclusion supported by data

Front 6

Not all explanations are scientific hypotheses.

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Example: Statements of opinion and hypotheses that use supernatural or mystical explanations that cannot be tested, fall outside the realm of scientific explanation.

Front 7

Controlled experiments

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use experimental groups and control groups to test a
hypothesis.

use independent variable and dependent variable for both experimental group and control group.

the control group and experimental group differ only in the independent variable, so the results of the experiment provide evidence-based conclusions.

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experimental group

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is the group in an experiment that experiences the experimental intervention or manipulation.

Front 9

control group

Back 9

is the group in an experiment that experiences NO experimental intervention or manipulation.

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independent variable

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is the variable, or factor, being deliberately changed in the experimental group, e.g., Coffee

Front 11

dependent variable

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is the measured result of an experiment. It is analyzed in both the experimental and control groups, e.g., the memory improvement.

Front 12

Four components of a controlled experiment in a scientific experiment are:

Back 12

Experimental group
Control group
Dependent variable
Independent variable

Front 13

Drawing Conclusions?
Confidence in scientific findings or in the result of study is increased by:

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a) Repetition of an experiment by other scientists (to support a hypothesis)

b) The Sample size (number of subjects) of the experiment
- The larger the sample size, the more likely the results will have statistical significance.

Statistical significance means that the results obtained are “real,” rather than due to a random chance.

Front 14

scientific theory

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A hypothesis that continues to hold up after many years of precise testing

a hypothesis that has never been disproved, even after many years of repeated testing, e.g., Cell theory, theory of evolution, and gravity.

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Epidemiology

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is the study of patterns of disease in populations, including risk factors.

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Correlation

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is a consistent relationship between variables. Data may show correlation between two variables, but it does not prove that one variable causes the other (cause and effect relationship).

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Why is it important to be cautious when making decisions based on a single epidemiological study?

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Complexity of a disease makes it unlikely that every variable can be controlled for.

Small sample sizes can influence accuracy of results.

The specific population of the study may not be representative of the general population.

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Evaluating scientific informationMedia and Public...

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(don't have time to go over lengthy peer-reviewed articles) In peer-reviewed journals the data and information are often very complex and the scientists interpret these data in lengthy discussion; so the general public may not receive important details because the media reports don’t have the time and space to explain all.

Journalists face unique challenges in covering health news since they must:
- cover complex topics
- do it quickly, creatively, accurately,
completely and with balance
- don’t dumb it down too much for
general news audience

can cause great harm to public by reporting incomplete and inaccurately.