1. Introduction to Scientific Method: REVIEW:Observation and Data
Honors Biology
Ms. Kim

2. Observation: using your 5 senses to collect information
Data: scientific information
Inference: a logical conclusion or assumption based on your observations

3. Example… Your cell phone is ringing in class  What is an observation?
I hear a ringing sound.
I see the phone light up.
What is an inference?
Someone is calling me.

4. DATA
2 TYPES:
Quantitative: includes observations or data that involves numbers (#’s), amounts or quantities
Qualitative: includes observations that DO NOT involve numbers; Observations or data that is descriptive.

5. Scientific Method

6. **(Initial) Observation : use your 5 senses
What are the steps?
**(Initial) Observation : use your 5 senses
1. State the problem or question:
●What are you trying to solve or research?
2. Form your hypothesis:
an educated or logical prediction to answer your problem question; use your prior knowledge
Not just a “guess”
IT MUST BE TESTABLE!!!
“If…then…because” statement
3. Plan your experiment:
●decide your procedure, control, variables & materials

7. 4. Perform your experiment: 5. Analyze your data (Results):
Collect data (both qualitative and quantitative)
5. Analyze your data (Results):
Make sense of your data
put it in LINE graphs/charts/table, etc.
6. Conclusion:
Sum up your findings (data)
Restate your hypothesis and state whether it is supported or not supported based on your results
CITE your quantitative and/or qualitative data!!! EXPLAIN your numerical data.
State and EXPLAIN any experimental error(s) (called error analysis)

8. Hypothesis Example:
What will happen to Derrick Rose’s shooting points during a Bulls game if he drank Gatorade everyday for 3 months?
IF Derrick Rose drank Gatorade everyday for 3 months, THEN Derrick Rose will score more shooting points BECAUSE the Gatorade will provide him energy and help his endurance last longer.

9. A Controlled Experiment
Experiment = process to collect data
There are 2 groups in an experiment:
Experimental (or test) group
Control group

10. Experimental vs. Control Groups
Experimental (Test) Group
Control Group
1 variable (thing) changes or is tested
Comparison group
No changes
“Normal” conditions

11. + Example: HOW WILL FERTILIZER AFFECT PLANT GROWTH?
WITH FERTILIZER WITHOUT FERTILIZER
(plants normally don’t have fertilizer)
>>>>ONLY CHANGE (test) 1 VARIABLE (thing): THE PRESENCE OF FERTILZER
Conditions (or standard variables) that NEED to remain
the same for a controlled experiment:
AMOUNT OF SUNLIGHT,
SOIL,
TYPE OF POT,
TEMPERATURE,
SPECIES OF PLANT
TEST GROUP + +
CONTROL GROUP

12. GOING BACK TO DERRICK ROSE:
What will happen to Derrick Rose’s shooting points during a Bulls game if he drank Gatorade everyday for 3 months?
Experimental group: Derrick Rose drinking Gatorade.
Control group: Derrick Rose not drinking Gatorade.

13. Independent Variable Dependent Variable
A controlled experiment will have 2 different variables:
Independent variable (“If….then…)
Dependent variable (If…then…)
Independent Variable
Dependent Variable
The thing (variable) that CHANGES in the experiment.
Ask “What variable changed in the experimental group?
“WHAT ARE YOU TESTING or CHANGING?”
Goes on x-axis
The measured outcome in the experiment.
Ask “What is being measured?”
Goes on y-axis

14. + + Independent variable: WHAT ARE YOU TESTING? Fertilizer
Example: HOW WILL FERTILIZER AFFECT PLANT GROWTH?
WITH FERTILIZER WITHOUT FERTILIZER
(plants normally don’t have fertilizer)
Independent variable: WHAT ARE YOU TESTING?
Fertilizer
Dependent variable: WHAT ARE YOU MEASURING?
Plant Growth
TEST GROUP + +
CONTROL GROUP

15. GOING BACK TO DERRICK ROSE’S EXAMPLE:
The independent, or manipulated variable, is (what are you testing?)
*Ex: The amount of Gatorade Derrick Rose drinks.
The dependent, or responding variable, is (what are we measuring/what’s the result?).
*Ex: Shooting points Derrick Rose will score during a game.

16. X- Axis = Independent variable
If time is present, it is usually ALWAYS goes on the x-axis (independent variable)
Y- Axis = Dependent variable

17. T.A.I.L.S for graphs T = Title is present
A = Correctly label x/y-axes (with label & units)
I = Use consistent intervals on axes
L = Label a key (if applicable)
S = Size (BIG graphs/use entire graph paper)

18. Now let’s practice with Spongebob…
Which people are in the control group? What is the independent variable? Patty Power Mr. Krabbs wants to make Bikini Bottoms a nicer place to live. He has created a new sauce that he thinks will reduce the production of body gas associated with eating crabby patties from the Krusty Krab. He recruits 100 customers with a history of gas problems. He has 50 of them (Group A) eat crabby patties with the new sauce. The other 50 (Group B) eat crabby patties with sauce that looks just like new sauce but is really just mixture of mayonnaise and food coloring. Both groups were told that they were getting the sauce that would reduce gas production. Two hours after eating the crabby patties, 30 customers in group A reported having fewer gas problems and 8 customers in group B reported having fewer gas problems.
What is the control group?
What is the independent variable?
What is the dependent variable?
Group B
New Sauce
Amount of gas

19. More practice with Spongebob…

20. Additional Information…
Essential to ALL experiments is:
Replication!!!
You NEED to consider your number of trials
Use the EXACT same conditions in EACH trial
Why?
To determine if the results are consistent  this INCREASES our confidence in the resulting data
BUT…
A certain amount of variation is NORMAL!
Increasing trial # allows us to obtain an AVERAGE RESULT from different trials.

21. Additional Information…
Essential to ALL experiments is:
2) Sample size
You NEED to consider your sample size when drawing conclusions
For example…
You are working with plants and decide to plant 2 control plants and 2 test plants.
1 test plant and 2 control plants die during the experiment
WHAT HAPPENS NOW? 

22. Additional Information…
Essential to ALL experiments is:
3) Clear procedure
Do NOT use pronouns!
Use “directional” language
Example:
Place ______ in _____.
Fill 20 ml of water in a 50 ml graduated cylinder
Someone MUST be able to REPEAT your procedure over and over to produce similar results!!

23. Theory vs. Hypothesis
Scientists test hypotheses MANY times in different ways! (i.e.- w/ new research tools, equipment, etc)
Many “types” of knowing…science-based knowledge based on careful, repeated observations/testable hypotheses.
THEORY = a well-tested explanation that is supported by A LOT of evidence (data)
Much broader than a hypothesis

24. Inductive vs. Deductive Reasoning
INDUCTIVE REASONING:
Derives general principles from specific observations
Ex: All organisms are made of cells – based on years of findings from biologists
DEDUCTIVE REASONING:
Reasoning flows from general to specific
Ex: If all organisms are made of cells, and humans are organisms, then humans are made of cells.