Science: What is a Hypothesis "There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery." - Enrico Fermi, American Physicist A Hypothesis can be supported or not supported based on the information gathered in the data.
LAB EXPERIMENTS Every experiment will share certain characteristics. Steps of the Scientific Method. They all must have: Problem or question -usually stated as a hypothesis Variables - factors that will influence the outcome of the experiment
LAB VARIABLES Independent variable (IV) – this is the factor that you are testing Dependent Variable (DV)– this is the factor that you will be measuring (it will change in response to the IV) Constants– those variables that must not change in the experiment. Must be given to both groups to maintain health of organisms.
Parts of a Controlled Experiment Experimental Group – receives the IV Ex. Tomato plants that get the fertilizer Control Group – does not get the IV Ex. Tomato plants that do not get fertilizer
HOW TO BEGIN Questions to ask when beginning an experiment: What are we trying to answer? What is the factor that we are testing? How will we know if that factor influenced the experiment? What other factors could possibly influence the outcome of the experiment?
TESTING LIVING THINGS Living things (organisms) change over time. They grow, mature and become exposed to disease and carry the genetic material that makes all things unique in the world We attempt to control each variable that could influence the life of that organism except the one we want to test (constants) This is a controlled experiment
Steps of an Experiment (order Sensitive) 1. Identify a problem 2. Background Research (has anyone else had the problem) 3. Develop a hypothesis: an educated guess 4. List Materials 5. Describe precisely your procedures: Great scientist should be so thorough so that the experiment could be redone with the exact same results. 6. Gather DATA 7. Present DATA in results section 8. Explain Results in a Conclusion
SUNFLOWER LAB ASSIGNMENT: Using Scientific Method, design a controlled experiment to determine if sunlight is necessary for the growth of sunflowers. Work in groups of 4 and create: 1) Hypothesis 2) List of Materials 3) Procedures (detailed steps) 4) Data tables, charts, graphs (leave them blank) 5) Analysis/Conclusion Questions
DESIGNING THE EXPERIMENT The Hypothesis Does your hypothesis relate to the question or problem? Is this a testable hypothesis? From your hypothesis, can you determine the IV and DV? Have you determined all the variables that should be constants (same for both groups)?
DESIGNING THE EXPERIMENT Have you clearly indicated the control group and the experimental group? Have you designed an effective way to record your data?
SCIENTIFIC METHOD You have just used the scientific method. 1. Observe the situation 2. Ask a question 3. Turn that question into a testable hypothesis 4. Predict the outcome of your experiment 5. Perform your experiment 6. Analyze the results 7. Evaluate your hypothesis
Cookbook Labs vs. Inquiry Labs Cookbook labs – experiment already designed for you Your task is to simply: 1. Follow procedures (directions) 2. Record your results in the tables,charts and graphs provided 3. Then draw your conclusions,usually by answering questions.
INQUIRY LABS Inquiry labs - you are asked to become the scientist, designing an experiment or set of experiments to resolve a problem. As the age old saying goes, you can’t solve the problem until you know what the problem is.
Inquiry labs require you to use the scientific method. Create a Title: Should be unique to YOUR experiment (Ex. “Pumpkin Seed Lab” is not UNIQUE) State the Question: What are you trying to find out? Background Research: Investigate what others have already learned about your question. Gather information that will help you perform your experiment.
State Your Hypothesis: After research, you should have some prediction about what you think will happen in your experiment. You must state your hypothesis in a way that you can measure results.
Develop a procedure for testing your hypothesis. - Number your steps - Include measurements of all materials - Include illustrations ** Remember to control all constants**
RECORDING YOUR DATA Two Types of Data: Quantitative – numbers, time, temperature, length, mass Qualitative – descriptive verbal, drawings Both types of data are important in conducting experiments
Create a Results Paragraph: - Summarize your results/data (tell the reader what is on the tables, drawings and graphs) - DO NOT discuss the hypothesis or conclusion
Draw Your Conclusion: This is your opportunity to explain the meaning of your results. Did your experiment support/not support your hypothesis? Use data to support your claim. Does additional research need to be conducted?
Report Your Results and Conclusion: This is the final product you would publish if you were a research scientist. When performing an inquiry lab, you will turn in your finished lab report detailing each step of the scientific method. Be sure you refer the rubric when writing your report.