The Scientific Method Logical & orderly approach to scientific research

Purpose Solve a problem Is there only 1 way to solve a problem?

Parts 5 basic parts 1.State the Problem 2.Form a Hypothesis 3.Conduct a Controlled Experiment 4.Gather and Analyze Data 5.Draw a Conclusion

1. State the problem Observe a certain problem or condition What do you want to know? Put it in question form? EX. Can a radish seed grow into a plant without sunlight?

2. Form a Hypothesis  An educated guess  An idea that can be tested  An if/then statement  EX. If radish germination is tested with & without sunlight then those seeds without sunlight will not sprout.

3. Conduct a Controlled Experiment Design for Solving a Problem Create procedures that others can follow to repeat the experiment The more times an experiment is repeated with the same results the more VALID the results become

Factors of an Experiment Variables 3 Types 1. Dependent Variable:  What is measured (Counts or records)  Y Axis on a graph

2.Independent Variable:  What is varied (changed)  X Axis on a graph *IMPORTANT* CAN HAVE ONLY 1 INDEPENDENT VARIABLE.

3. Control Variables:  What is held constant  Anything that if changed could affect the outcome

Experimental Control:  Where the independent variable is either eliminated or set as a standard value  What you compare your results to

Practice SpongeBob and his Bikini Bottom pals have been busy doing a little research. Read the description for each experiment and answer the questions.

1 - Patty Power Mr. Krabbs wants to make Bikini Bottoms a nicer place to live. He has created a new sauce that he thinks will reduce the production of body gas associated with eating crabby patties from the Krusty Krab. He recruits 100 customers with a history of gas problems. He has 50 of them (Group A) eat crabby patties with the new sauce. The other 50 (Group B) eat crabby patties with sauce that looks just like new sauce but is really just mixture of mayonnaise and food coloring. Both groups were told that they were getting the sauce that would reduce gas production. Two hours after eating the crabby patties, 30 customers in group A reported having fewer gas problems and 8 customers in group B reported having fewer gas problems. Which people are in the control group? (The group that used the mayonnaise mixture) What is the independent variable? (The type of sauce) What is the dependent variable? (Amount of gas problems) What should Mr. Krabs’ conclusion be? (That the new sauce reduces gas problems) Why do you think 8 people in group B reported feeling better?

2 – Slimotosis Sponge Bob notices that his pal Gary is suffering from slimotosis, which occurs when the shell develops a nasty slime and gives off a horrible odor. His friend Patrick tells him that rubbing seaweed on the shell is the perfect cure, while Sandy says that drinking Dr. Kelp will be a better cure. Sponge Bob decides to test this cure by rubbing Gary with seaweed for 1 week and having him drink Dr. Kelp. After a week of treatment, the slime is gone and Gary’s shell smells better. What was the initial observation? (Gary has slimotosis) What is the independent variable? ( cures) (There isn’t one, He had 2) What is the dependent variable? (Amount of slimotosis) What should Sponge Bob’s conclusion be? (The combination of Rx’s works, but not sure if individually they would)

Design a Controlled Experiment  EX. 1. Fill two small cups with soil. 2. Gently bury 3 radish seeds in each cup. 3. Water each cup with 25 mL of water. 4. Place one cup in sunlight (control) and one in a dark place. 5. Water each cup with 25 mL of water every other day. 6. Record results of growth in cm. 7. Record final results after 1 month.

4. Gather and Analyze Data Written records of your data Can be verbal descriptions, drawings, measurements, or numbers Try to find similarities, differences, or patterns about your data Use data tables to organize your results  EX. Sunlight cup grew 2cm, 4 cm, and so on….. Dark cup 0 cm, 0 cm…

Observations vs. Inferences “You can observe a lot just by watching.” - Yogi Berra

Observations An observation is the gathering of information by using our five senses: Sight Smell Hearing Taste Touch There are two types of observations Qualitative Quantitative

Qualitative Observations Qualitative observations describe what we observe. “Qualitative” = quality (descriptive) These observations use adjectives to describe something. Example: The flower has white petals. Example: Mr. M has blue eyes.

Quantitative Observations Quantitative observations measure what we observe. “Quantitative” = quantity (numerical) These observations use numbers to measure something in a quantitative way. Example: The flower has seven petals. Example: Mr. M has two eyes.

Which is better? Both types of observations are valuable in science. In an experiment though, quantitative observations can be precisely and objectively compared. Qualitative: The road is long. (describes) Quantitative: The road is 5 km long. (measures) Some things are easier to quantify than others. Scientists use innovative ways of turning qualitative into quantitative.

Which is better? For example, someone might say that a dead fish is smelly. It is hard to know just how smelly the fish is though. To make this quantitative, the scientist could ask the person to rate the “smelliness” on a scale of 1-5. This would then allow you to compare how smelly the fish is!

Inferences Inferences are an explanation for an observation you have made. They are based on your past experiences and prior knowledge. Inferences are often changed when new observations are made. Again, observations are information we gather directly through our five senses….inferences help explain those observations!

Here are some examples! Observation: The grass on the school’s front lawn is wet. Possible inferences: It rained. The sprinkler was on. There is dew on the grass from the morning. A dog urinated on the grass! All of these inferences could possibly explain why the grass is wet. They are all based on prior experiences. We have all seen rain, sprinklers, morning dew, and dogs going to the bathroom.

Here are some examples! Observation: The school fire alarm is going off. Possible inferences: The school is on fire. We are having a fire drill. A student pulled the fire alarm. Again, these are all logical explanations for why the fire alarm is going off.

Last one! Observation: A student is sitting in the main office. Possible inferences: ? Why might a student be sitting there?

Inference and Observation Activity

On your paper make two columns : ObservationInference

5. Draw a Conclusion Draw inferences from the results of your experiment EX. The researcher believes that radish seeds need sunlight to grow The results are “evidence” not necessarily proof Evidence is a basis for theories Theories are supported by repeated testing Theories that are universally valid & have a high degree of probability are called; Scientific laws or Principles 

Remember…  You should NEVER CHANGE the data you receive -it is OK if your hypothesis is wrong -you may then change the experiment to try to prove your hypothesis again  Be very careful and precise in your measurements, you want your results to reflect the test (experiment) results NOT experimental errors