Upload
kovit
View
57
Download
0
Embed Size (px)
DESCRIPTION
Experimental Design and Science. Designing an Experiment. Can you name the 6 concepts of experimental design?. independent variable. dependent variable. constants. control group. experimental group. repeated trials. You will be divided into lab table groups - PowerPoint PPT Presentation
Citation preview
Experimental Design Experimental Design and Scienceand Science
Designing an Experiment
Can you name the 6 concepts of experimental design?
Can you name the 6 concepts of experimental design?
independent variableindependent variable
dependent variabledependent variable
constantsconstants
control groupcontrol group
experimental groupexperimental group
repeated trialsrepeated trials
Experimental DesignExperimental Design
You will be divided into lab table groups Each table will analyze a different
experiment for the design parts. Use the form in front of you to answer all
the questions.
Experimental Design DiagramExperimental Design DiagramTitle: The effect of ...IV... on ...DV...
Hypothesis: If the ...IV... is modified in this way,then this will happen to the ...DV...
Independent variable:
these boxesshow how theIV is modified
_____trials _____trials _____trials _____trials _____trials
Dependent Variable:
Constants:
Control:
Scenario 1: Compost and Bean PlantsScenario 1: Compost and Bean Plants
After studying about recycling, members of Jessica's biology class investigated the effect of various recycled products on plant growth. Jessica's lab group compared the effect of different aged grass compost on bean plants. Because decomposition is necessary for release of nutrients, the group hypothesized that older grass compost would produce taller bean plants Three flats of bean plants (25 plants/flat) were grown for 5 days. The plants were then fertilized as follows: (a) Flat A: 450 g of three-month-old compost, (b) Flat B: 450 g of six-month-old compost, and (c) Flat C: 0 g compost. The plants received the same amount of sunlight and water each day At the end of 30 days the group recorded the height of the plants (cm).
Experimental Design DiagramExperimental Design DiagramTitle: The effect of different aged compost on beanplant growth.
Hypothesis: If older compost is applied, then plantgrowth will be increased.
Independent variable: Age of Compost
these boxesshow how theIV is modified
3 month oldcompost
6 month oldcompost No compost
# trials 25 trials 25 trials 25 trials
Dependent Variable: Height of plants (cm)
Constants: amount of light, water, compost
Control: no compost
Scenario 2 Metals & Rusting Iron Scenario 2 Metals & Rusting Iron
In chemistry class, Erza determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Ezra read that a utilities company was burying lead next to iron pipes to prevent rusting Ezra hypothesized that less rusting would occur with the more active metals. He placed the following into separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water.
Experimental Design DiagramExperimental Design DiagramTitle: The effectiveness of various metals in preventing the rusting of iron.
Hypothesis: I f the chemical activity of the metallic wrapper is increased, then less rusting of iron will occur.
Independent variable: Type of metal wrapping strip these boxes show how the IV is modified
Iron nail with no metal
Iron nail with magnesium
Iron nail with aluminum
Iron nail with lead
# trials 1 trial 1 trial 1 trial 1 trial
Dependent Variable: amount of rusting , color of water
Constants: amount of water, mass of metal, type of nail
Control: nail with no metal
Perfumes & Bee's BehaviorPerfumes & Bee's Behavior
Evelyn read that certain perfume esters would agitate bees. Because perfume formulas are secret, she decided to determine if the unknown Ester X was present in four different perfumes by observing the bees' behavior. She placed a saucer containing 10 ml of the first perfume 3 m from the hive. She recorded the time required for the bees to emerge and made observations on their behavior. After a 30-minute recovery period, she tested the second, third, and fourth perfumes. All experiments were conducted on the same day when the weather conditions were similar, e.g., air, temperature and wind.
Experimental Design DiagramExperimental Design DiagramTitle: The effect of various perfumes on the behavior of bees.
Hypothesis: I f the perfume contains Ester X, then the bees will display agitated behavior.
Independent variable: Type of perfume these boxes show how the IV is modified
Perfume 1 Perfume 2 Perfume 3 Perfume 4
# trials 1 trial 1 trial 1 trial 1 trial
Dependent Variable: time to emerge , behavior of bees
Constants: amount of perfume, weather, distance from hive
Control:
Fossils and Cliff DepthFossils and Cliff Depth
Kenzie observed that different kinds and amounts of fossils were preset in a cliff behind her house. She wondered why changes in fossils content occurred from the top to the bank. She marked the bank at five positions: 5,10,15, 20, and 25m from the surface. She removed 1 bucket of soil from each of the positions and determined the kind and number of fossils in each sample.
Experimental Design DiagramExperimental Design Diagram
Title: The effect of depth on the different types and amounts of fossils.
Hypothesis: If depth increases in a fossil bank, then different fossils will occur.Independent Variable: Depth of soil
Modifications 5 10 15 20 25# of Trials1 1 1 1 1
Dependent Variable: Amount and type of fossils.Constant: 1 bucketControl ?
Aloe vera and PlanariaAloe vera and Planaria
James read that Aloe vera promoted healing of burned tissue. He decided to investigate the effect of varying amounts of aloe vera and regeneration of planaria. He bisected the planaria to obtain 10 parts (5 heads and 5 tails) for each experimental group. He applied concentrations of 0%, 10%, 20%, and 30% Aloe vera to the groups. Fifteen ml of Aloe vera solutions were applied. All planaria were maintained in a growth chamber with identical food, temperature, and humidity. On day 15, James observed the regeneration of the planaria parts and categorized developed as full, partial, or none.
Experimental Design DiagramExperimental Design Diagram
Title: The effect of aloe vera on regeneration of planaria.
Hypothesis: If more aloe vera is used then there will be an increased amount of planaria regeneration.
Independent Variable: Percentage of Aloe VeraModifications10% 20% 30%# of Trials 10 10 10
Dependent Variable: amount of regenerationConstant: food, temperature, humidityControl : 0% aloe vera
Experimental Design Experimental Design and Scienceand Science
Are you a design expert?