1. Experimental Design Review
Use this information as a study tool.

2. Experimental Design Vocabulary
Hidden Variable
Any constant that changes unexpectedly during an experiment
Level
The degree to which the independent variable is changed
Repeated Trials
Repeating the experiment over and over again, at least 3 trials

3. Homework 8.24.07 Study your notes for the short test on Friday
Read “Refining Experiments”
Complete the Anticipation Guide
We will use the Anticipation Guide to review before taking the test on Friday.
You will begin a lab write up on “The Great Tomato Race.”
This lab will be due on “ ” It will be worth 150 points. Most of it requires you to cut an paste information from the “Experimental Design Ditto into your Journal”
Follow the guidelines for “Keeping a Scientific Journal”

4. Starter: Analyzing Data 8.23.07
Temperature of the Ketchup
The Average speed of the Ketchup
2nd
3rd
4th
6th
7th
Average Temperature
Hot
Cold
Room
There are three levels of change in this experiment. What are they?
If you look at the first level of change, you will notice that the average data for each class period is different. Why do you think the data for each class period or group looks different?

5. Oops: We made a few mistakes
Used different brands of ketchup
Recorded data in inches instead of centimeters
Shook the paper plates
Allowed the ketchup to flow for more than 30 seconds
Forgot to record all of our data
Used room temperature water instead of hot water
Forgot to read the directions very carefully
Measured incorrectly

6. Another Variable
Even though some scientists perform the same experiments, they, often, don’t get the same results as other scientists.
Although their data may look different, they probably notice that the trend or pattern is similar.
The difference in the recorded data could have created a margin of error known as a hidden variable.
A hidden variable is a constant that changed unexpectedly. Sometimes, these hidden variables can really mess up an experiment.

7. Hidden Variables in the Great Tomato Race
The temperature
The same number of ice cubes
Did we check to see if the temperature of all three levels were the same for each group?
Did we really tilt the plate at a 45 degree angle? Do you think this changed the way that our data looked?

8. Experimental Design Vocabulary
Hidden Variable
Any constant that changes unexpectedly during an experiment
Level
The degree to which the independent variable is changed
Repeated Trials
Repeating the experiment over and over again, at least 3 trials

9. Homework
Complete the “Before Reading” column of the “Refining Experiments” anticipation guide.
Read about “Refining Experiments” pages 9-11.
Complete the “Refining Experiments” Cornell Notes
Complete the “After Reading” column of

10. Experimental Design Vocabulary Starter: 8.23.07 (Page 6)
Question is the ___________ you are trying to solve in an experiment
__________ is the predicted answer to the problem
__________ is a factor in the experiment that is changing
_____________ is the one factor that the experimenter changed on purpose
_____________ is the one factor that the experiment did not change on purpose, but can see changing and will measure it somehow
____________ is all of the factors that are kept constant in an experiment
____________ is the degree to which the independent variable is changed
Repeated Trials consist of repeating the experiment over and over again, at least 3 trials

11. More Vocabulary
______________ is observation data, usually gathered by using your 5 senses.
______________ is numerical data usually gathered by either counting or measuring.
Line graphs show a direct relationship between the independent and dependent variable in an experiment.
Analysis or to analyze means to interpret the data
A ____________ is your final thought or answer in an experiment.

12. Experimental Design Vocabulary Starter: 8.23.07 (Page 6)
Question is the problem you are trying to solve in an experiment
Hypothesis is the predicted answer to the problem
Variable is a factor in the experiment that is changing
Independent Variable is the one factor that the experimenter changed on purpose
Dependent Variable is the one factor that the experiment did not change on purpose, but can see changing and will measure it somehow
Constant is all of the factors that are kept constant in an experiment
Hidden Variable is any constant that changes unexpectedly during an experiment
Level of change is the degree to which the independent variable is changed
Repeated Trials consist of repeating the experiment over and over again, at least 3 trials

13. More Vocabulary
Qualitative Data is observation data, usually gathered by using your 5 senses.
Quantitative Data is numerical data usually gathered by either counting or measuring.
Line graphs show a direct relationship between the independent and dependent variable in an experiment.
Bar graphs show an indirect relationship between the independent and dependent variable in an experiment.
Analysis or to analyze means to interpret the data
A conclusion is your final thought or answer in an experiment.
A theory is a well-test explanation (Big Bang Theory)
A scientific law describes a reoccurring pattern in nature