Scientific Method

What is the scientific Method? Science is about solving problems Scientists use a sequence of steps when solving a problem Uses a combination of reasoning and observation.

Steps of scientific method 1.Define the problem you are trying to solve 2.Make observations and formulate a hypothesis a.Gather information (research) b.Make observations using your five senses c.Based on gathered information and your observations, you would make a hypothesis— possible explanations for the problem.

Steps of scientific method 3.Experiment a)Design an experiment that will test your hypothesis b)Experiment must be repeatable i.e. other scientists must be able to repeat your experiment 4.Observe and collect data a.Take detailed notes so other scientists will know what happened in the experiment.

Steps of scientific method 5.Repeat the experiment a)Repeat steps #3 and #4 several times. Experiment must be done exactly the same. b)This ensures that the results are reproducible, there are no other external factors affecting the results and your theory has a solid basis. You have to do the experiment exactly the same as before 6.Formulate a theory/make conclusions a.Compare the results of the experiments b.Decide if your hypothesis is correct

EXAMPLE Olivia has a new plant that needs sunlight to grow. After a few weeks, the leaves start turning brown Olivia is concerned that the plant might be getting too much light. We can use to scientific method to find out why the plants leaves are turning brown

EXAMPLE 1. Define the problem: The leaves of the plant are turning brown 2. Make observations & formulate a hypothesis: The leaves are turning brown because they are getting too much sunlight.

EXAMPLE 3. Set up experiment to test hypothesis: Let’s take three pots of the same plant (pot A, pot B and pot C) and keep them in the following conditions for two weeks. Pot A—put in sunlight for the whole day, treated the same way as Olivia has been already doing Pot B—put in complete shade for the whole day Pot C—put in partial sun light, where it gets sun for only half of the day

EXAMPLE 4. Make observations & collect data from experiment: After two weeks, observe the leaves of each plant and see if they are brown or green. Pot A—the leaves are brown, dry and the plant seems unhealthy Pot B—the leaves are droopy, looking wilted and the plant seems unhealthy Pot C—the leaves are green and the plant looks healthy

EXAMPLE 5. Repeat the experiment several times: Olivia repeated the experiment 4 times and got the exact same results 6. Formulate a theory and conclude. Based on the experiments and the observations, it seems that Olivia’s hypothesis was correct and that the leaves are turning brown due to too much sun.

Scientific Method Questions 1.It is a method important for researchers to find answers to their questions. It uses a scientific approach to determine testable experiments in order to formulate a theory and answer a specific problem.

Scientific Method Questions 2.Only B can be tested with the scientific method. Scientists cannot design a repeatable experiment for A and C

Scientific Method Questions 1. Define problem: The cheese disappeared from the counter 2. Make observation & formulate hypothesis: No one in the family ate the cheese and there was a mouse found in the house the previous week. The hypothesis is that a mouse ate the cheese. 3. Set up experiments to test hypothesis: Set up a camera that attaches to the mousetrap with the cheese, so that if there is a mouse it will be caught and the camera will take a snap shot of the thief. 4. Make observations & collect data: Look at the snapshots and check the mousetrap and see if there are any mice in the picture or the trap. 5. Repeat experiments & data collection: Repeat this experiment for three nights. 6. Formulate a theory: If the camera shots or the mousetrap shows a mouse eating the cheese, than our hypothesis is true.

Variables and Controls The 2 types of variables are the independent variable and the dependent variable – The independent variable is what is being manipulated or changed in the experiment. – The dependent variable is the expected outcome from changing the independent variable. Controls or control groups are the subjects that are not being changed in the experiment.

Example for Variables and Controls A company wants to test how effective their new fertilizer is: – They will test the new fertilizer against their older fertilizer. The independent variable is the – new fertilizer. The dependent variable is – how well the new fertilizer works The control group will be the same plants that are – untreated