Learning Targets Students will be able to describe the characteristics of living things Students will be able to describe the characteristics of living things Students will be able to identify experimental variables Students will be able to identify experimental variables

EXPERIMENTAL DESIGN

Work Time Work with a partner to define the variables/terms on your worksheet Work with a partner to define the variables/terms on your worksheet Also identify the variables/terms from John’s experiment Also identify the variables/terms from John’s experiment In about 15 minutes we will go over these In about 15 minutes we will go over these

Independent Variable Also called: Manipulated variable Also called: Manipulated variable Is the variable you purposely change Is the variable you purposely change The independent variable is the CAUSE of any differences you measure in the dependent variable The independent variable is the CAUSE of any differences you measure in the dependent variable

John’s Independent Variable Fertilizer types Fertilizer types

Dependent Variable Also called: Responding variable Also called: Responding variable The variable that responds to the change, and is due to the effect of the independent variable The variable that responds to the change, and is due to the effect of the independent variable This variable is measured/counted after you set up the experiment This variable is measured/counted after you set up the experiment

John’s Dependent Variable Height of plant (cm) Height of plant (cm)

Constant Factors that remain the SAME for all trials and groups Factors that remain the SAME for all trials and groups

John’s Constant Amount of water and sunlight Amount of water and sunlight

Control (Group) Group that does not contain the independent variable Group that does not contain the independent variable Also called the “No treatment group” or “normal treatment group” Also called the “No treatment group” or “normal treatment group”

John’s Control Group Flat C: no fertilizer Flat C: no fertilizer

Trial The number of organisms/object per group The number of organisms/object per group The number of times the experiment is repeated The number of times the experiment is repeated

John’s Trials 3 flats or 25 plants per flat or 1 time overall 3 flats or 25 plants per flat or 1 time overall

Hypothesis The results you expect to obtain from the experiment The results you expect to obtain from the experiment A written (if/then) statement detailing the expected results A written (if/then) statement detailing the expected results If part: discusses the independent variable and some experimental details If part: discusses the independent variable and some experimental details Then part: discusses the expected results and how the data is collected/measured) Then part: discusses the expected results and how the data is collected/measured)

John’s Hypothesis If flats of bean plants are treated with various fertilizers then Flat A’s plants receiving the commercial fertilizer will show the highest stem growth (in cm) after 5 days If flats of bean plants are treated with various fertilizers then Flat A’s plants receiving the commercial fertilizer will show the highest stem growth (in cm) after 5 days

Variables in data tables Data tables can have several arrangements, but we will look at one example (similar to the example on your homework) Data tables can have several arrangements, but we will look at one example (similar to the example on your homework)

Beth and James HW Due on Friday – use the last part of class to start the homework and ask questions if you have them Due on Friday – use the last part of class to start the homework and ask questions if you have them

Exit Slip On a half sheet of paper: On a half sheet of paper: Write your name and hour Write your name and hour Write down what the object was that you brought in Write down what the object was that you brought in Write a brief explanation of how it demonstrates the characteristics of life (is your object an example of one specific characteristic). Do NOT just say because it was alive…elaborate on the characteristics we went over! Write a brief explanation of how it demonstrates the characteristics of life (is your object an example of one specific characteristic). Do NOT just say because it was alive…elaborate on the characteristics we went over!

James and Gas Mileage 1)Purpose: to determine which gas type obtained the best gas mileage 1)Purpose: to determine which gas type obtained the best gas mileage 2) Independent variable: Type of gas 2) Independent variable: Type of gas 3) Dependent variable: mileage obtained 3) Dependent variable: mileage obtained 4) Constants: driving in city 4) Constants: driving in city 5) Number of trials: 3 5) Number of trials: 3 6) Control? NO 6) Control? NO Why? Why? 7) Data Table (See next page) 7) Data Table (See next page) 8) Type of graph: Bar 8) Type of graph: Bar

Independent Variable Dependent Variable Derived Quantity Octane Concentration Mileage driven on 2 gallons of gas Trials Total Average gas mileage Low Regular High

John’s Experiment 8 points 8 points 1 pt for each question (if data table is not filled in correctly, it is just -1) 1 pt for each question (if data table is not filled in correctly, it is just -1)

Beth and Ants 1) Independent variable: type of food 1) Independent variable: type of food 2) Dependent variable: number of ants 2) Dependent variable: number of ants 3) Constant: time (10 minutes), number of ants (50) 3) Constant: time (10 minutes), number of ants (50) 4) Trials: 3 4) Trials: 3 5) Control: Empty plate 5) Control: Empty plate 6) Purpose: determine ant food preference 6) Purpose: determine ant food preference 7) Data table: (next slide) 7) Data table: (next slide) 8) Type of graph: Bar 8) Type of graph: Bar Why? Why?

Independent Variable Dependent Variable Derived Quantity Type of Food Number of ants Trial Total Average number of ants Bread Onion Sugar Bologna Empty

Beth’s Experiment 8 points 8 points 1 pt for each question (if data table is not filled in correctly, it is just -1) 1 pt for each question (if data table is not filled in correctly, it is just -1) Write a total out of 16 points on this side of the worksheet Write a total out of 16 points on this side of the worksheet

Graphing Criteria Title Title Units (g, cm, etc.) on the X + Y axis Units (g, cm, etc.) on the X + Y axis Label the X + Y axis Label the X + Y axis Create the proper graph Create the proper graph Ex. Line vs. Bar (line shows trends over time, bar compares different items) Ex. Line vs. Bar (line shows trends over time, bar compares different items) Create a Key Create a Key

Key Dependent (units) Independent (units) Title Key

Bubble Gum Lab Chomp Chomp Chomp Chomp