The Scientific Method

1. The Scientific Method Susan Baker Associate Professor of Science

2. Methods of Science • How do scientists learn about the natural world? • Discovery science – attempts to describe nature • Darwin’s work as a naturalist • Human genome project • Hypothesis-based science – attempts to explain nature • Experiment based • Focus of today’s presentation

3. Hypothesis-based Science • The scientific method describes a framework by which hypothesis-based science is conducted. • Scientific method has been described as organized common sense. • It’s a methodical approach to problem-solving.

4. Scientific method is based on a belief that there is underlying order to the natural world. • Goal of science is to understand and explain that order.

5. Scientific Method • Make observations • or consider the observations/research of others • From observations come questions • Develop hypotheses to explain the observations or to answer the questions raised • Use inductive reasoning to develop hypotheses

6. Scientific Method 4. Test hypotheses • Deductive reasoning • Make predictions, if hypothesis is true then…. • Test accuracy of the prediction • Repeat the process, test new hypotheses… • Analyze results and draw conclusions • Share findings and conclusions

7. Observations • Observations must be recordable and repeatable

8. Hypothesis • Hypothesis – tentative explanation of observations • Hypothesis development requires creativity and an open-mind

9. Hypothesis • Hypothesis development uses inductive reasoning • From specifics  general • Hypotheses are supported by limited data • More data/observations the better the hypothesis

10. From Hypothesis to Experiments • Use deductive reasoning to make a prediction based on the hypothesis • If the hypothesis is true what else will be true? • Deductive reasoning…general  specific • Test the prediction(s) under controlled conditions • Goal is to confirm or falsify the hypothesis

11. Common Research Design Set up two groups: • An experimental group • A control group as a standard for comparison • The control group is Identical to experimental group except for the variable being studied • Easier said than done with human research!

12. Research Variables • Independent variable – condition being studied • Researcher controls/set this variable • Dependent variables – ones that change due to the independent variable • Data taken • Controlled variables – conditions held constant

13. Interpreting Results • Outcome of the experiment(s) will either support or disprove the hypothesis • Never prove a hypothesis is 100% correct! • Always alternate hypotheses. • A hypothesis gains credibility when many experiments fail to disprove it.

14. Your Papers for Jon! • Observations • Hypothesis • Prediction • Testing the hypothesis – the experiment

15. Share Findings • Important to publish or present the research to the wider community • Shares new knowledge and adds to the observations of a discipline • This leads to new questions, new hypotheses… • Research and conclusions stand open to verification and new interpretations • Research stands open to criticism • Good research can withstand this!

16. Scientific Theory • A hypothesis is elevated to a scientific theory when it is supported by a significant amount of data and it explains a broad range of observations • Theories are subject to rigorous testing and revision when needed • Darwin’s theory of evolution by natural selection is an example of a theory

17. Research Sources • Primary sources • Report on research conducted by the author • Secondary sources • Report on research conducted and published by others

18. Format for Primary Journal Articles • Abstract – summary/overview of all components below • Introduction • Why the research was conducted • The research question/hypothesis stated clearly • Methods • What was done • Results • What was found • Discussion • What the findings mean, limitations of the research • New questions raised from this research • References

19. “The intellectual labor of scientists consists of constructing a coherent picture of the world from what they sift out as noteworthy and significant.” Ruth Hubbard