The scientific method consists of four important steps: hypothesis, experimentation, observation and conclusion. The hypothesis is the question and how you think it will be answered; the experimentation is the procedure you use to test your hypothesis; the observation is the data you gather during your experimentation; and the conclusion is what you deduct from your data. When presenting a project using the scientific method, include your procedure, materials used and data collected along with your hypothesis and conclusion.
Oil Spill Effects on Aquatic Plants
Write a hypothesis, such as, "I think oil will negatively affect aquatic plants." Conduct your experiment by placing a hyrdilla plant in each of two beakers, one-half to two-thirds full of water. Place a funnel, wide side down, around each hydrilla plant. Fill a test tube with water and invert it, slipping the mouth of the test tube over the narrow opening of the funnel so that the plant is completely encased in water. Set both beakers in a well-lit location so that both beakers receive the same amount of light and are exposed to the same temperature. Pour an ounce of motor oil into one beaker. Observe the effects of the oil on the health of the plants as well as the amount of oxygen that forms within the test tubes. Record your data and write a conclusion based on your observations. Alternatively, try using different species of aquatic plants and different amounts of oil.
Plant Growth Enhancers and Fertilizers
Decide on a hypothesis, such as, "I think plant enhancers increase plant growth," or, "I think plant enhancers have no effect." Fill two pots with potting soil. Plant one bean (mung bean, green bean or pea) in each pot. Place the pots in a location so that both are exposed to the same amount of sunlight and the same temperature. Add a fertilizer or growth stimulant to one pot. Apply the same amount of water daily to each pot. Measure the plants and observe their health each day. Record your data and conclude whether fertilizers have a positive, negative or no effect on plant growth. Try conducting this experiment with different species of beans and different fertilizers or growth enhancements. The light, water, soil and temperature variables should be constant for each experiment. Conclude as to whether fertilizers and growth enhancements are beneficial or not.
Water Displacement and Flotation
Write a hypothesis regarding why heavy objects can float while small objects can sink. Test your hypothesis by cutting out five equally-sized squares of aluminum foil. Roll each square into a ball of a different size. Measure and record the diameter of each ball, ranging from the ball being largely air-filled to the ball being compact. Place each ball in a tub of water. Record which balls float, which sink and how far each ball that doesn't sink is immersed in the water. Write a conclusion as to why some objects sink and others float, based on your data. Alternatively, try the experiment with differently-shaped objects, objects made of different materials or floating the objects on salt water as opposed to fresh water.
Ingredient Substitutes in Food
Hypothesize as to whether sugar alternatives result in finished products of the same quality and taste. Test your hypothesis by creating three batches of lemonade: one using sugar, one using honey and one using artificial sweetener. Use the same amount of water and lemon juice or extract for each batch. Have at least 10 people taste the three batches and comment on their flavor. Record your data. Write a conclusion stating whether the opinions of your volunteers led you to believe that all sweeteners result in a similar product or if there are differences. Try your experiment with other foods, such as cookies, cakes or ice cream. Another option is to compare identical items, such as sugar cookies or ice cream (both with natural sweeteners and with artificial sweeteners) that are pre-made and determine if volunteers can taste a difference.
- ScienceStuff.com: The Scientific Method
- Science Buddies: Steps of the Scientific Method
- All Science Fair Projects: Effects of Oil Spills on Aquatic Plants
- All Science Fair Projects: The Usefulness of Plant Growth Enhancers
- Science Buddies: Archimedes Squeeze: At What Diameter Does an Aluminum Boat Sink?
- Science Buddies: Sugar vs. Sugar Substitutes: Are They Just as Sweet?
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