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Experimental Design Diagrams

Part II: Create an Experimental Design Diagram for each of the following scenarios. Use the format from the notes.

Scenario 1: Compost and Bean Plants

After studying about recycling, members of John’s science class investigated the effect of various recycled products on plant growth. John’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 beans (25 plants / flat) were grown for 5 days. The plants were fertilized as follows: Flat A: 450 g of three-month-old compost, Flat B: 450 g of six-month-old compost, 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 in cm.

Scenario 2: Metals & Rusting Iron

In his science class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with 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 (masses) of the metals, and the same type and size of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large by analyzing the color of the water.

Scenario 3: Perfumes and Bees’ Behavior

JoAnna read that certain perfume esters (odor causing chemicals) would agitate bees. Because perfume formulae are secret, she decided to determine whether 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 about the bees’ behaviors. After a 30 minute recovery period, she tested the second, third, and forth perfumes. All experiments were conducted on the same day when weather conditions were similar – that is air, temperature, and wind.

Scenario 4: Fossils and Cliff Depth

Susan observed that different kinds and amounts of fossils were present in a cliff behind her house. She wondered why changes in fossil content occurred from the top to the bottom of the bank. She marked the bank at five positions: 5, 10, 15, 20, and 25 m from the surface. She removed one bucket of soil form each of the positions and determined the kind and number of fossils in each sample.

Scenario 5: Laughter and Learning

Carter’s objective was to determine if laughter could be proven to be beneficial in a learning environment. The latest research shows it can increase awareness, release tension, commit facts to deeper memory, and enhance the outcome of group activities. With this in mind, Carter hope to prove that laughter can be an important tool to improve learning. In the experiment, Twenty-four students wee tested in various learning skills with and without the use of laughter. Each person received a test that was divided into sections according to the following skills: memory (visual & audio), concentration, team participation, and comprehension. Test score based on a standard test for each. At the end of the project the average test scores were determined and compared.

Scenario 6: Aloe vera and Planaria

Jackie read that Aloe vera promoted healing of burned tissue. She decided to investigate the effect of varying amounts of Aloe vera on the regeneration of planaria. Planaria are aquatic flat worms that regenerate body parts when severed. Jackie bisected the planaria to obtain 10 parts (5 head sections and 5 tail sections) for each experimental group. She 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, Jackie observed the regeneration of planaria parts and categorized the development as full, partial, or none.

Scenario 7: Cartons and Hole Height

Susie wondered if the height of the hole punched into the side of a quart-sized milk carton would affect how far from the container the liquid would spurt when the carton was full of liquid. She used four identical cartons and punched the same size hole in each. The hole was placed at a different height on the same size of each container. The height of the holes varied in increments of 5 cm ranging from 5 cm to 20 cm from the base of the carton. She put her finger over the holes and filled the carton to a height of 25 cm with water. When each carton was filled to the proper level, she placed it in the sink and removed her finger. Susie measured how far from the carton’s base the water had squirted when it hit the bottom of the sink.  

Scenario 8: Music and Concentration

Kim’s project was designed to test whether different genres of music would induce a hamster to run faster through a maze. She reviewed many studies on the Mozart effect. The Mozart effect is the theory that Mozart’s music can raise IQ scores, cut learning time, improve creativity, heal the body faster, etc. Kim then considered the fact that some people think that rock or country music would be better for them and decided to run a hamster through a maze with different types of music to see what effect each type of music has in the Hamster. She predicted that Mozart would be more effective at aiding the hamster through the maze. To conduct the experiment she trained the hamster (Sparky) to go through the maze by putting a sunflower at each corner of the maze. Next, she ran Sparky through the maze with no music and recorded the time it took for complete and she noted the number of times Sparky made an error in the maze. The next day Kim ran Sparky through the maze playing the music for fifteen minutes before she ran him through the maze, then continued to play it until he had finished the maze. Kim repeated this process using Mozart, County, Rock and Rap music. Because of Sparky’s nocturnal habits Kim played the music from around 6-7:00 PM, so that he would be alert at the performing time. Kim only performed the trial once each day so that Sparky would have almost the same alertness every day.

Scenario 9: Spices vs. Bacteria

The objective of this study was to see if certain spices kill bacteria. Five spices were selected for this experiment; they were cinnamon, cloves, garlic, thyme and turmeric. A water extract and an alcohol extract were prepared from each of the spices. The extracts were tested for antibacterial effect using the ring method and the direct method. In the ring method filter papers were soaked with the extracts and dried. The filter papers were then hole punched to get discs. Four of these discs were then put in each of 10 Petri dishes (5 for water extracts of each spice and 5 for alcohol extracts) that contained agar media containing bacteria from my mouth. The dishes were then incubated for 48 hours at 37oC. Ring formation was then observed. In the Direct method the spice extract was already added to the agar medium. Bacteria from the mouth were then added to the Petri dishes. The Petri dishes were then incubated at 37oC for 48 hours. The number of bacteria in each dish was then counted. In both the disk method and the direct method, the control dishes did not have spice extracts.

Scenario 10: Sugar and Bone Density

The objective of this project was to determine if the acid in soda will decrease bone density. Sam hypothized that children who drink more than five cans of soda per week will have a low bone density. To complete thi project, informed consent was given to 200 (11-14 year olds). A questionnaire was given out to all of the students that participated in this experiment. The questionnaire asked about how much soda, water and milk they consume per week, exposure to sunlight, race, vegetable consumption and exercise. Each of the participants were placed into test group based on their usage of water, milk or soda. The subjects then took an ultrasound test to determine their bone denisty.

Scenario 11: Plant Cell Division

Landon designed a project to test onion root tips and how they react to different nutrient solutions. These results were then applied to the principles of mitosis. Landon believes that plants grown with Miracle Gro will have progress through mitosis faster and grow faster. Plants are submerged in 12ml of water, two plants for each of three nutrient solutions (Carbonated Water, Miracle Gro, Salt water and purified water). Each plant was tested for fourteen days, making daily observations of the health and growth of the plant.

Scenario 12: Online or In-Store

When going to find the perfect gift for a friend or relative, have you ever found the prices at stores too high? Or have you ever not even been able to find the gift in-stock at the local stores? The vast world of online shopping may have just what you are looking for. Kasper decided to explore the World Wide Web and what it has to offer for bargain hunters and last minute gift givers. Since the early 1990s, when the Internet developed into the phenomenon it is today, online shopping has been getting bigger and bigger, thanks to it’s factory pricing and calm, relaxed, and at-home atmosphere. Is it really cheaper to shop online? Until now, that question has not been researched or looked into very deeply. Kasper believes that shopping online provides better deals and values than shopping in stores. To test his hypothesis that online would be cheaper, Kasper went to stores with cheap prices, found an item, recorded the price, and then went online to compare that item. He then recorded the online prices of 5 different web stores (listed store A-E) for that one item to see just how much cheaper which would be and why. Kasper recorded the prices of a CD, Polo Shirt, book and a pair of shoes.  

Part II: For each scenarios above, Develop one new testable reserach question and one new hypothesis. Find at least one reference that supports the hypothesis made (use in-text citations and make a Reference list)


Scenario 1:

Improvement: Kim could have used male and female hamsters.

Testable Question: What effect does gender and music have on a Hamsters ability to complete a maze with limited error?

Hypothesis: If Mozart music is played then female hamsters will complete the maze faster and with no error before male Hamsters.

Support: Smith (2009) states that female hamsters are more alert than male hamsters. This makes them more capable of complete complex mazes faster that male hamsters.


Reference list

Scenario 1:

Smith, J (2009). Hamsters. retrieved 02/13/2040, from All About Hamsters Web Site:

Use these examples as the format for completing Part II.