# Scientific Method.

## Presentation on theme: "Scientific Method."— Presentation transcript:

Scientific Method

Scientific Method This lab is designed to make you more familiar with the process of scientific investigation. The scientific process of inquiry is outlined by steps. These steps are collectively called the Scientific Method. The steps are: Observation Question Hypothesis Experiment Results Conclusion

Step 1 -Observation Observation and description of a phenomenon or group of phenomena. Must be detectable and measurable .

Step 2- Question Formulation of a question to explain the phenomena
Looking at cause and relationship to other phenomena

Step 3 - Hypothesis Formulation of an hypothesis to explain the phenomena .

Step 3 - Hypothesis How do you think you can solve the problem? The hypothesis step is always written in the form "If ___________, then ___________. The blank after the "if" is called the independent variable. The independent variable is just whatever you are going to do to solve the problem.

Step 3 - Hypothesis How do you think you can solve the problem? The hypothesis step is always written in the form "If ___________, then ___________. The blank after "then" is the dependent variable. The dependent variable is what you think will happen when you do whatever the independent variable is. For example, if your hypothesis is that "If I take an aspirin, my headache will go away," your independent variable is "taking an aspirin" (this is what you do) and your dependent variable is "the headache will go away" (what happens as a result of your having done something).

Step 4- Experiment Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments.

Step 5 - Results When you did the experiment, what happened? What did you see, hear, smell, etc? You should give a complete accounting of all data that you take (sometimes this is referred to as the "Data" section). There's an old saying among chemists: "If you didn't write it down, then it didn't happen." Make sure you write everything down!

Step 6 - Conclusion What do the results mean? Was your hypothesis correct? This section should be only one sentence long. Don't make this any longer than it has to be!

Scientific Method The experiment must consider all possible variables. Variables are things which could be changed during the of the experiment. Independent (experimental or test) variable is manipulated by the experimenter and does not change throughout the course of the experiment. Dependent variable is likely to change as a result of the independent variable. This the variable that is measured. Control (standardized) variables are those that are held constant throughout the experiment.

Scientific Method We want our experimental results to be reproducible. Our confident level will be set at 95%, which means that for every 100 times that the experiment is performed, 95 of those will have the same conclusion.

Scientific Method To test our hypothesis ( Ha) , we attempt to contradict another hypothesis called the null hypothesis ( Ho). The Null hypothesis states that there are no differences ( “null” effect) between treatment.

Scientific Method Research hypothesis (Ha ) states that there is a significant difference between the treatments. Null hypothesis (Ho) states that there is no significant difference between the treatments.