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

Question Independent Variable (What I change) Dependent Variables (What I observe) Controlled Variables (What I keep the same) How much water flows through a faucet at different openings? Water faucet opening (closed, half open, fully open) Amount of water flowing measured in liters per minute The Faucet Water pressure, or how much the water is "pushing" "Different water pressure might also cause different amounts of water to flow and different faucets may behave

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