An Organized Approach to Solving Problems SCIENTIFIC METHOD An Organized Approach to Solving Problems

Scientific Method Organized problem solving Not a single method

Steps of the Scientific Method Define the Problem Collect Information About the Problem Form a Hypothesis Experiment Collect Results Conclusion Repeat

Step 1. Problem What are to trying to find out? - Usually based on observations - stated as a question Example: I notice that on warm nights crickets seem to chirp more often Problem = Does temperature affect the rate of cricket chirps?

Step 2. Collect Information About the Problem Information can be gathered from: - your own observations - published research textbooks, articles, internet etc…

Step 3. Form a Hypothesis A possible solution to your problem Must make a prediction Must be possible to be disproved - UFOs exist is not a scientific hypothesis because it is impossible to disprove

Formal Hypothesis A formal hypothesis used in an experiment should be stated in If…Then form. - It relates directly to the experiment to be conducted and explains the expected outcome -If I do this…..then that will happen. Example: If I raise the temperature I keep crickets in, then they will chirp more.

Step 4. Test Your Hypothesis-Experiment Experiment must be controlled - tests only one thing at a time A controlled experiment compares a control group with an experimental group The control group provides a normal standard against which the biologist can compare results of the experimental group. The experimental group is identical to the control group except for the one factor being tested - the variable being tested is the independent variable Emphasize that there is only one difference between two groups

Experimental Design Needs to be repeatable Should test a large sample Should be without bias

Variables Variable = anything that can change in an experiment Controlled variables = What do I keep the same? Independent variables = What do I change? aka Manipulated variables Dependent variables = What do I measure? aka Responding variables

Cricket Experiment 20 crickets grown in a 10 gallon aquarium Control Group Experimental Group 20 crickets grown in a 10 gallon aquarium 12 hours of light/day Fed 5 g Acme Cricket Food Kept at 60 degrees F 20 crickets grown in a 10gallon aquarium 12 hours of light/day Fed 5 g Acme Cricket Food Kept at 80 degrees F

Step 5 Data and Results Data = observations or measurements - Quantitative = number data 10 chirps/minute - Qualitative = observations color changed to orange Results = Processed data – makes the meaning of the data more clear. Allows you to see trends or patterns. Calculate an average, graph of data etc..

Graphing Your Data Independent Variable- the factor that is changed before the experiment begins. It goes on the x-axis. Sometimes called manipulated Dependent Variable- the factor that you ran the experiment to measure, sometimes called results. It goes on the y-axis. Sometimes called responding

Sample Graph Dependent Variable: on the Y Axis Independent Variable on the X Axis

Conclusions Was your hypothesis correct? - do the results support your hypothesis What are possible sources of error? What next? – What question could you study next? Why is this important?

Repeat Your Work/Publish Repeat experiment to confirm your results. When scientists have completed their work, they publish their results - this informs other scientists of their findings

Theory A hypothesis that has been tested repeatedly and shown to be correct becomes a theory Theories can explain current observations and predicts new observations A theory is as close to certainty as you get in science

Vocabulary to Know and Love hypothesis experimental group control group variable controlled variables independent/manipulated variable Dependent/responding variable data quantitative data qualitative data Results theory