The Scientific Method. The Scientific Method. The Scientific Method. The Scientific Method 10/28/2010

Transcription

1 The scientific method is the only scientific way accepted to back up a theory or idea. This is the method on which all research projects should be based. The Scientific Method is used by researchers to support or disprove a theory. Thanks to and Dr. Paul Brooks involves 6 steps: Observation Question Hypothesis Method Result Conclusion Observation- You observe something in the material world, using your senses or machines which are basically extensions of those senses. AH Look at this! 1

2 Question- You ask a question about what you observe. State the problem or question. Hypothesis- You predict what you think the answer to your question might be. Steps of the Scientific Method 3. Formulate a Hypothesis: Predict a possible answer to the problem or question. Example: If soil temperatures rise, then plant growth will increase. Method - You figure out a way to test whether the hypothesis is correct. The outcome must be measurable (quantifiable). Record and analyze data. 2

3 Steps of the Scientific Method 4. Experiment: Develop and follow a procedure. Include a detailed materials list. The outcome must be measurable (quantifiable). Do you know the difference between the independent and dependent variables? Independent Variable The independent, or manipulated variable, is a factor that s intentionally varied by the experimenter. Dependent Variable The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable. 3

4 Constants The constants in an experiment are all the factors that the experimenter attempts to keep the same. Control Group In a scientific experiment, the control is the group that serves as the standard of comparison. The control group may be a no treatment" or an experimenter selected group. Control Group The control group is exposed to the same conditions as the experimental group, except for the variable being tested. All experiments should have a control group. Result- You do the experiment using the method you came up with and record the results. You repeat the experiment to confirm your results by retesting. 4

5 Steps of the Scientific Method 5. Collect and Analyze Results: Modify the procedure if needed. Confirm the results by retesting. Include tables, graphs, and photographs. When Does Correlation Imply Causation? Yellow cars have fewer accidents People who sleep less live longer Ice-cream sales are strongly (and robustly) correlated with crime rates. Scientific research finds that people who use cannabis (A) have a higher risk of developing a psychiatric disorder (B) State Conclusion- You state whether your prediction was confirmed or not and try to explain your results. X mean = 9.0, variance = 11.0 Y mean = 7.5, variance =

6 Steps of the Scientific Method Scientific Method 6. Conclusion: Include a statement that accepts or rejects the hypothesis. Make recommendations for further study and possible improvements to the procedure. 10/27/2010 By W. Ribbeck Basic Steps (The Rattlesnake Experiment) Definition Scientific method: basic steps that scientists follow in uncovering facts and solving scientific problems Basic Parts of Scientific Method Stating the problem (Question) Gathering information (Observation) Suggesting an answer for the problem (Hypothesis) Performing an experiment to see whether the suggested answer makes sense (Methods) Recording and analyzing the results of experiments or other observations (Results) Stating conclusions (Conclusions) 6

7 Stating the Problem What invisible trail does a rattlesnake follow in tracking down its bitten prey? Gathering Information A rattlesnakes eyes are only sensitive to visible light A pair of organs located under the eyes detect invisible light in the form of heat A rattler s tongue smells certain odors in the air The sight or smell of an unbitten animal does not trigger the rattler s tracking action Hypothesis After the snake wounds its victim, the snake follows the smell of its own venom to locate the animal Experiment Drag a dead mouse that has been struck and poisoned by a rattlesnake along a curved path on the bottom of an empty cage Place the snake in the cage The snake follows the exact trail that has been laid out Control Drag an unbitten dead mouse along the path The snake seems disinterested 7

8 Recording and Analyzing Data Do the experiment many times Record the data Conclusion The scent of venom was the only factor that could cause a rattlesnake to follow its bitten victim. Four golden lessons Steven Weinberg, Nature November 2003 The Assignment! No one knows everything, and you don t have to; Search out the unknown, the challenging; You won t always be right or on target when pursuing creative work (new knowledge); Learn something about the history of science. 8

9 How is a research article organized? Introduction Background information and observations Justification for new research Research questions Hypotheses to be tested Where? When? How? Methods Results Quantitative report of the data Statistics Figures and graphs 9

10 Discussion and Conclusions Conveys the importance of the results Does data support hypotheses? Puts results in context of other research Summarizes the key findings of the research 10