Scientific Method

5 Basic Steps 1. Identify the problem 2. Form a hypothesis 3. Experiment 4. Results 5. Conclusions

I. Identify the problem. AKA: Ask a question Based on observations –What counts as an observation? Anything you can observe - How do we observe things? Use our 5 senses HearTasteTouch SeeSmell

II. Hypothesis AKA: prediction –A good prediction always includes “if” or “because” –This is the reason why you think something will turn out the way you predict. Hmm… If I, then

III. Experiment Has 3 main components –A. List your materials –B. Identify your variables –C. Write out your procedure

III. Experiment A. Materials A list of materials should be very specific. The next person to carry out your experiment should know just what to use. I’m supposed to use ¼ of a flask of water. ---What size flask? ---Should I use tap or distilled water?

III. Experiment- B. Identify variables 1. Independent variable 2. Dependent variable 3. Control

Independent variable AKA— –Manipulated variable –Experimental variable –Experimental group This is actually your “variable.” (this is what you “vary,” change, experiment on, and/or manipulate.) Almost always plotted on a graph’s x-axis. Water will change from a liquid to a solid if I put it in the freezer, because of the lower temperature. Independent variable: Temperature

Dependent variable This is how the independent variable and the effect of that variable is measured. Almost always plotted on the y-axis. Water will change from a liquid to a solid if I put it in the freezer, because of the lower temperature. Dependent variable: temperature & judgement about the state of the water See example >>>>> y :state of the water 0=liquid 1=liquid 2=beginning to form chips of ice 3=somewhat slushy 4=more slushy 5=solid ice

Control This is a variable that is kept constant and/or in its natural state. Ex: Water in the freezer (at reduced temperature) = independent variable or experimental group Water left alone (at normal temperature) = control We keep controls to see what happens if we do not manipulate what we are experimenting on. We must compare to see if our manipulation is making the difference. Other controls: same amount of water in freezer as on countertop same size container that the water is in under both conditions same amount of time for each condition

III.3.c Procedure A very detailed set of instructions explaining how you will carry out your experiment. Someone who knows NOTHING about your experiment should be able to carry out your experiment exactly like you did by following your listed procedure.

IV. Results Has 3 parts –Written explanation of what happened –Data table –Graph

Results-explanation “ The water changed to a solid at 32 degrees F.” –Results are very factual. –Simply tell what happened –Do not offer any reasons why or if this is what you expected.

Results-Data Table X (temperataure) Y (state of matter) 50 degrees0 32 degrees5 -Always include a legend or key explaining your data set. See above. y :state of the water 0=liquid 1=liquid 2=beginning to form chips of ice 3=somewhat slushy 4=more slushy 5=solid ice Water’s temperature versus state of matter

Results-Graph Degrees Farenhiet Water’s temperature versus state of matter -Always title your graph and its axes. -Plot independent variable on x-axis -Plot dependent variable on y-axis

V. Conclusion Has 3 parts –Compare results to hypothesis –Form a theory –Suggest recommendations for future research

V.A. Compare We need to know if your experiment turned out the way that you expected it to. –Somehow restate your hypothesis “ We thought that water would change to a solid if the temperature was lowered to 32 degrees F, and our results matched this hypothesis.”

V.B. Theory Ask yourself– “Why did my experiment turn out this way?” –Your reasoning in answering this question IS YOUR THEORY! “Well, our experiment didn’t turn out as expected. I think that our thermometer was defective. I’m not sure if it was accurate.” “Our experiment turned out just as we expected. From past experience and readings we have observed water change from a liquid to a solid at this temperature. It seems as if this could be a natural law.

Extra note on forming your theory… –Your theory is also known as an inference. This is different from a prediction. You now have some evidence to support what you think. You did not directly observe your conclusion but have a controlled environment with evidence to support your experiment, thus you INFER about what happened (make a conclusion).

V.C. Suggest recommendations Science should never end!!! –Always add to your experiment. –What you find out this time can help you like building blocks or stepping stones for future experiments. –This is also a way for you to correct your mistakes if any were made (like a defective thermometer)…Give it another try.