Sept. 4 Bell work 1. What do you use to make qualitative observations? 2. What do you use to make quantitative observations? 3. Observations need to be ___________ and ______________. 4. What is an inference? 5. What is a prediction?

Scientific Method Problem Research Hypothesis Experiment Data Conclusion Retest

Problem  What do you want to learn?  Keep the problem statement specific and focused.

Research Find out as much about your topic as you can. Information will help you to form a hypothesis and make a guess about the experiment’s outcome. Investigate these sources: Written materials (books, magazines, etc) Experts Conferences or lectures

Hypothesis Predict the answer to the problem. All hypotheses should include: Focus of the experiment What’s being measured Conditions Expected results The hypothesis statement is usually worded as an “if, then” statement. The scientist predicts what he/she thinks the outcome will be if he/she conducts an experiment. Examples: If pitfall traps are set up at GMS, then many different kinds of insects will be caught. If a toy car is rolled down a toy ramp, then the toy car will roll faster when weights have been added to the toy car. (Hint: A good format is: If “this is done”, then “this will happen”.)

Experiment  A test to confirm or disprove your hypothesis.  In an experiment you must:  Use instruments that measure  Decide which controls and variables should be used  Determine the length of the experiment  Use trial and error  Be able to repeat the results  Be a good observer  Measure exactly Control – experiment without the variable Variable – factor being tested

Analysis Data Collected Observations made during the experiment What steps were important to the experiment What did I do that had the greatest effect on the experiment? The least? No effect? Events and any changes throughout the experiment. Errors Tentative conclusions

Conclusion  Ask these questions:  What did I find out?  Did the results of the experiment confirm my prediction?  Did the results deny my prediction?  Are there any questions that remain unanswered?  Are there any changes that could have been made?  As a result of the experiment, are there any suggestions or new questions to test?  Was this experiment important?

Retest In order to verify the results, experiments must be retested.

Variables What is a variable? Variables are factors or conditions that affect the results of a situation or concept and are often tested in an experiment. A variable is a change that can be controlled by the experimenter when doing an experiment or scientific investigation.

Three Kinds of Variables Independent or manipulated variable Dependent or responding variable Controlled variable

Independent or manipulated variable A factor or condition that is intentionally changed by an investigator in an experiment.

Dependent or responding variable A factor or condition that might be affected as a result of a change.

Controlled variable A variable that is not changed.

Control An experiment without the variable. In other words, you do the experiment without changing anything.