Chapter 1

How science is done

1. observations lead to questions 2. pick a question and look into scientific literature to see if anyone has asked the question before 3. if the initial question is novel, by itself or is building on research, a hypothesis can be performed 4. test the hypothesis with experiments 5. analyze the results of the experiment 6. decide to support or reject the hypothesis 7. if the hypothesis is supported the data from the experiment could be published to a scientific journal, if not the hypothesis could be revised and retested

Process of science

1. observe, gather data 2. develop an testable/falsifiable hypothesis 3.conduct test/ experiment 5. analyze results, gauge significance 6. if hypothesis if falsified, modify your predictions; if the hypothesis is supported continue with additional tests 7.make conclusions by peer review

Describe the process and features of a controlled experiment

Controlled experiments have two groups: the control group and the experimental group & they differ only in the independent variable. There is also an independent and dependent variable. The independent variable is changed in a deliberate way and is used on the experimental group. The dependent variable is an result of the changes made to the experimental group (IV).

Why does correlation not represent causation?

Correlation between two variables does not necessarily mean causation because it could be a number of other factors causing experiments to sway a certain way. Although, correlation can provide hints to certain relationships, it is not the end all be all. Correlations provide suggestive evidence that merit more investigation. Several factors can influence the strength of conclusions in a scientific study including: bias of researchers, demographics of patients, patients state of health and methods used during studies.

everyday meaning of theory vs. scientific meaning of theory

Everyday: refers to an idea that the would like to follow up on and is based on personal experience and knowledge Ex: You feel more cheerful when you wear bright colors Scientific theory: a hypothesis that that has never been disproved by many years of rigorous testing/thousands of scientific experiments Ex: Cell theory- all living things are made of cells

Explain how seemingly contradictory scientific results may be explained by differences in how the study was performed.

Good scientific studies don't always produce the same results because science is constantly evolving and changing. Conclusions based on evidence can always be modified in the future. Scientists could also have different hypothesis that they test with similar results. Scientists also go about approaching experiments in different ways. For example, health risks associated with certain drugs and food could be affected by other factors like: a individuals overall health, an individuals lifestyle choices, psycho-graphics of individuals and demographics of individuals. Any variable that is unknown could affect the results of an experiment

Explain why popular media may not accurately convey the results of scientific studies.

Popular media may not accurately convey the results of scientific studies because media reports don't have the time, space and expertise to thoroughly explain all information from a scientific studies. During the translation of a complex study to a media headline, some important details and potential limitations of a single-study may not be conveyed. Most media headlines reflect a correlation, not a causation. There may be an important connection between two factors, but no direct evidence that the two relate. Also, certain parts of a population may have been excluded from a study. Scientific study reports provide a large amount of information and the public receives them as isolated media headlines. A skeptical consumer should ask

Why is sample size a concern in designing and interpreting scientific studies?

Sample size can strengthen our confidence in the results of a scientific study. The larger the sample size, the more likely the results will have statistical significance ( not due to chance). Larger sample sizes produce more reliable data because the more data collected in an experiment, the more you can trust the conclusions.

What is science?

Science is a way of knowing, a method of seeking answers to questions through observation and experiments.

compare and contrast conclusions derived from rigorous scientific study and anecdotal studies

The difference lies in the evidence supporting the conclusions about the studies. With rigorous scientific study, many people have studied and performed different experiments based on the initial observation and hypothesis and have all arrived at the same conclusion. . With anecdotal evidence, it is typically the conclusion from one or even a group of people based on no scientific study or testing. Most of the time, anecdotal evidence is based on personal experience, which would be a fine way to start the scientific process—by asking questions about that experience.

experiment

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

correlation

a consistent relationship between two variables

randomized clinical trial

a controlled medical treatment in which subjects are randomly chosen to receive either an experimental treatment or a standard treatment (a placebo)

Science is

a human endeavor, a body of knowledge, systematic process, ongoing and never finishing, a reliable standard for application

testable

a hypothesis is testable if it can be supported or rejected by carefully designed experiments or observational studies

statistical significance

a measure of confidence that the results obtained are "real" and not due to chance

peer review

a process in which independent scientific experts read scientific studies before they are published to ensure that the authors have appropriately designed and interpreted the study

hypothesis

a tentative explanation for scientific observation or question

scientific theory

an explanation of the natural world that is supported by a large body of evidence and has never been disproved; the highest point of scientific knowledge

In a scientific experiment, which group would typically receive a placebo treatment?

control group

falsifiable

describes a hypothesis that can be ruled out by data that show that the hypothesis does not explain the observation

placebo

fake treatment given to control groups to mimic the experience of the experimental group

positive correlation

independent and dependent variable increase

negative correlation

independent increases, dependent decreases

anecdotal evidence

informal personal observations

correlation

is not causation

scientific hypothesis

must be testable and falsifiable

What is typically the order of the scientific process?

observation, question, hypothesis, experiments, data, conclusions

experimental group

the group that experiences the manipulation

control group

the group with no manipulation

sample size

the number of experimental subjects or the number of times an experiment is repeated; in human studies, sample size is the number of participants

Once a scientific hypothesis has been tested and supported by one scientist in one study

the same hypothesis must be tested in different ways by different researchers, both to refine it and to increase our confidence that it is the best explanation for the observations in question.

epidemiology

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