Transcript Document
1
1
An organized set of steps used to solve a problem.
Is there a certain number of sets?
NO!
It is simply a logical way to solve a problem.
Can you form conclusions about something before you test it?
NO!
Can you form conclusions about something before you state a hypothesis?
NO!
3
Clip 4
EXAMPLE
(1) Observation: Something done through the five senses.
- “My shampoo doesn’t clean my hair!” (2)State the problem: - “I need a shampoo that will clean my hair better.”
(3) Form a Hypothesis: - “ If I use “Pert” instead of “Suave,” then my hair will feel cleaner.”
5
(4) Test the Hypothesis through an experiment: -How could I set up this experiment?
Performing a GOOD experiment What makes an experiment a GOOD experiment?
Answer: It truly tests for what it is supposed to test for.
Question: How can we make sure that our experiment is a GOOD experiment?
6
Setting up a Rules: GOOD experiment
7
(1) An experiment usually contains two variables.
What’s a variable?
Something that can change...or have more than a single value.
Two variables: (1) Independent Variable (manipulated) (2) Dependent Variable (responding)
What are the variables in our experiment?
Independent Variable: What the experimenter..YOU.. changes.
Types of Shampoo.
What do think will happen if we change the types of shampoo?
Our hair will be cleaner.
So, the Dependent variable “Feel of our hair.” is the
8
Setting up a GOOD experiment
9
Rules: (2) All experiments need a control.
A control is something to compare the experiment to.
What’s our control?
Our regular shampoo. “Pert”
Setting up the Experiment
10
For two weeks we will use “Pert” and then for two weeks we will use “Suave.” How can we make sure that the shampoo is the only factor affecting how our hair feels?
1.
2.
3.
4.
Use the same shower.
Make sure temp. is the same everyday.
Do not put anything else on hair.
Either blow dry everyday or never blow dry.....
why?
These are called CONSTANTS.
They do not change.
11
Why do we need Constants?
To make sure we are testing for what we said we are testing for.
12
After the Experiment
(5)Analyzing the data “What is the data telling me?” What did we learn?
-”Pert” made my hair feel cleaner.
(6)Draw conclusions.
Was the hypothesis supported?
YES!
What does this data mean for the future?
-I will use “pert”.
13
How can we be sure that the results are real?
14
15
What’s a theory?
Scientific Theories are based on knowledge gained from many experiments.
NOT A GUESS!
16
17
18
19
Redi’s Experiment on Spontaneous Generation 20 OBSERVATIONS: maggots appear on the meat.
HYPOTHESIS: Flies land on meat that is left uncovered. Later, Flies produce maggots.
PROCEDURE: Controlled Variables : jars, type of meat, location,temperature, time Uncovered jars Covered jars Manipulated Variables: gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear
Several days pass
No maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.
Observation vs. Inference
21 An observation is the information gathered using any of your senses.
An inference is an explanation of the data based on facts but not on direct observation.
Inference vs. Observation Statement Object A is round and orange.
Object A is a basketball.
Observation Inference X X Object C is round and black and white.
Object C is larger than Object B.
Object B is smooth.
X X X Object B is a table-tennis ball.
X Object A is a basketball.
Object B is a table-tennis ball.
Object C is a soccer ball.
EOCT Questions
21
22
A B C D a hypothesis an inference an observation a prediction
A student wants to determine the effect of salt on the freezing point of water. A student adds 200 mL of pure water to three identical containers. To one container, 2 g of the salt is added; in the second container, 4 g of the salt is added; and in the third container no salt is added. The three containers are placed in the same freezer. The temperature of the water is measured every 10 min for one hour, and the observations are recorded in a data table. What is the independent variable in this experiment?
A the amount of salt added B the temperature measured C the type of salt used D the type of container used 23