1. Parts of an Experiment

2. Essential Questions What is the difference between independent and dependent variables? Why do we only test one variable at a time? What are the parts of an experiment? What is the difference between quantitative and qualitative data?

3. Variables Things that can change in an experiment  Only test one variable at a time  Test only 1 variable at a time so that you know what produced your results  Only have 1 independent variable at a time

4. Independent Variable:  Variable being test – manipulated  Variable that experimenter can change  Graphed on x-axis – horizontal  Temperature on this graph

5. Dependent variable:  changes as a result of the changing independent variable  Graphed on y-axis - vertical  Experimenter doesn’t control  Pressure on this graph

6. Constant:  Variables in an experiment that doesn’t change  Something that is the same for all groups in an experiment Control group: ― All variables are kept the same; no independent variable ―Group for comparison with experimental group Experimental group: ― The independent variable is changed

7. Experimental Data - Information Quantitative Data:  Experimental data that includes measurements(numbers) Qualitative Data:  Experimental data that includes color, texture, shape etc.

8. Homework 8/30 Interactive Reader Pgs.1- 7 Reading check questions 1-15 Due Date: 9/1/10

9. What are units and Standards? What is the difference between accuracy and precision? What is the SI System? Why do scientist use the SI System? Scientific Measurement

10. Standards and Units A.Standard 1.Fixed and agreed upon values 2.Actual or accepted value a.Used as a reference for accuracy B. Units 1.Identify the type of measurement for given value a. dollars, miles, gallons, apples

11. Precision and Accuracy A.Precision 1.Getting the same value again and again 2.Number of significant digits in a measurement B. Accuracy 1.How well you use the equipment 2.How close a measurement/value is to the actual or accepted value

12. The International System of Measurement SI – Systeme` International System that scientist use all over the world so that they can share information Modern form of the Metric System

13. Nano n 1 billionth