2. SUBJECTIVE VS. OBJECTIVE
Subjective: outcomes are based on the tester’s
feelings and opinions. (Used in the arts)
ex: “I don’t like you because I think you’re ugly…”
Objective: a judgment based on fact, not on
personal feelings or opinions. (Science must
use this)
ex: “I’ll buy this car because it gets the best gas mileage.”

3. SCIENTIFIC METHOD
1. Recognize a problem
2. Make and educated guess-a hypothesis-about the answer
3. Predict the consequences of the hypothesis
4. Perform experiments to test predictions
5. Formulate the simplest general rule that organizes your finding based
on your hypothesis, predictions and results of experimentation
We use this general method daily though we may not think of it
“WEAR THE PANTS”

4. VARIABLES IN EXPERIMENTATION
In any experiment, there can be many variables.
The important thing is to only change one
variable in an experiment at a time, if you want
to isolate true cause and effect of
experimentation.

5. THINK-PAIR-SHARE
Give an example of changing one
variable at a time.

6. HOW GOOD IS A MEASUREMENT?
“Mr. Basso, how well do I have to measure?”
(story of the plumb-level)
Accuracy vs. Precision
(Think-pair-share: what’s the difference?)
share your definitions on the board

7. PRACTICING ACCURACY
Think-Pair-Share
A block of brass that weighs 500 grams is weighed on a digital scale.
Students practice their use of a scale. The students report their results:
Student 1: measures 497 grams
Student 2: measures 501 grams
Student 3: measures 503 grams
Student 4: measures 497 grams
Student 5: measures 496 grams
Are these student’s measurements Accurate?

8. PRACTICING PRECISION
Think-Pair-Share
Students measure a length of wood with a measuring tape. It’s known
measurement is 16’ 1-1/16” long:
Student 1: measured 16’ 1-1/8”
Student 2: measured 16’ 1-1/8”
Student 3: measured 16’ 1-1/16”
Student 4: measured 16’ 1-1/16”
Student 5: measured 16’ 1-1/8”
Are these students accurate?

9. EXAMPLE OF ACCURACY AND PRECISION

10. EXAMPLE OF ACCURACY AND PRECISION
Accuracy: How close do you get to the actual measure/mark
Precision: Is the measurement repetitively close to each other

11. In science we need to try to be both accurate and
precise!