Scientific Principles: lecture 2

1. Scientific Principles: lecture 2

2. 1. How did scientists study nature in the past?  Define bias and naturalist. • Naturalist observe and record nature as they see it. Biased, did not use the scientific method. • Bias = subject, human interpretation

3. 2.  Compare laboratory and field scientists.  How is their work similar?  How isit different? • Naturalist and lab scientists use observation • Field scientists have difficulty controlling variables – temp, light, animal location all change constantly. • Lab scientists easier to control environment. • Both use scientific method

4. 3. What is the scientific method • Science - A process used to solve problems or develop an understanding of nature that involves testing possible answers. • Scientific Method - Method of gaining information about the world by forming possible solutions to questions, followed by rigorous testing to determine if the proposed solutions are valid.

5. 4.  What is the difference between objective and subjective? • Objective = unbiased, multiple test graded by machine example: no human input • Subject = human interpretation, bias, human error likely • Scientific method tries to be objective using controls and a standard method.

6. 5. Steps of scientific method • Observation - Occurs when we use our senses, or extension thereof, to record an event. • Background – literature review, find out what other scientists have discovered.

7. 5. Steps of Scientific Method • Hypothesis - A testable statement that provides a possible answer to a question, or an explanation for an observation. • A good hypothesis must be logical, account for all relevant information, allow prediction of related future events, and be testable. • Given a choice, the simplest hypothesis with the fewest assumptions is the most desirable.

8. 5. Steps of Scientific Method • Experiment - Re-creation of an event enabling an investigator to support or disprove a hypothesis. • Controlled - Separate variables and divide experiment into experimental and control groups, differing by only one variable. • Reproducibility - Experiment is repeated to eliminate unconscious bias. • Independent investigators must be able to reproduce the experiment.

9. 5. Steps of scientific method • Run experiment and record results • Graphs • Data tables • Summarize data and graphs

10. 5. Steps of Scientific Method • Publishing - Results must be publishedfor peers to be able to examine and criticize. • A hypothesis supported by many experiments and by different investigators is considered reliable.

11. 5. Overview Elements of the Scientific Method

12. 6.  What is the difference between inductive and deductive reasoning? • Inductive = insight, intuition used to form a hypothesis • Deductive = conclude, deduce, interprete results

13. 7.  What is the difference between a control and a test variable? • Control = standard, consistant, does not change, • Test variable = changes

14. 8. Development of Theories and Laws • Theory - A widely accepted, plausible generalization about fundamental scientific concepts that explain why things happen. • Kinetic Molecular Theory • Theory is also often used in a much less restrictive sense to describe a vague idea. • Scientific Law - A uniform or constant fact of nature that describes what happens in nature. • Law of Conservation of Mass

15. 9. How do lab reports relate to sci method? • Abstract: brief summary of experiment w/ hypothesis, overview • Intro: observation, background (lit review) and hypothesis • Methods: materials and describe how the experiment was run • Results: data tables, graphs, data and graph analysis • Discussion: was the hypothesis supported? What did other scientists find? • Conclusion: summary • References: cite references used