Investigation: What Are the Processes of Science? Part 1: Background Information Often we think of science as something that only happens in laboratories where people where white lab coats and safety glasses. In reality, scientific processes are performed every day, by everyone. It's the process you go through when you try to solve a problem, like "Why isn't my car starting?" The steps you might take to answer this question are similar to the steps scientists might take to answer their questions. Most scientists agree to a common language of problem solving called "The Scientific Method," which is often described as a stepbystep methodology for solving problems. To be fair, there are many different ways to practice science, and not all of them use this procedure. For example, Jane Goodall did not use these exact steps to study chimpanzees in Gombe, but she incorporated many of the practices to help her understand chimpanzee behavior. The following steps outline the general methodology for science process, but it is important to understand that not all research follows this orderly list. There are many different ways to do science! Step 1: Make an Observation Most science starts with an observation or identifying that a problem exists. For example, your first observation might be that your car doesn't start, and that is a problem. Step 2: Ask a Question Often these questions are causal as they try to get to the reason or explanation for why something happened or what caused it to happen. Obviously, in our example, the question is: "Why is my car not starting?" Step 3: Generate a Hypothesis (or hypotheses) A hypothesis is a possible explanation for a phenomenon. It attempts to explain an observation. When doing science, it is acceptable to generate many possible explanations for the observation or problem. Step 4: Design a Test One kind of test, called a controlled experiment is used to test a hypothesis. In its simplest form, a controlled experiment involves two groups treated identically except for the factor identified in the hypothesis. This factor is called the experimental or independent variable. The experimental group is exposed to the experimental variable and the control group is not. Before you carry out your experiment, you should also identify the dependent variable. This is the factor that you will measure as part of the test to confirm or reject your hypothesis. You will also need to decide how many times you will repeat your test to improve reliability and how you will eliminate any other causes for your results. Step 5: Making Predictions Predictions state what you think will happen and are usually framed in "If Then" statements. For example, if my hypothesis is true, then this should happen. Step 6: Analyze Results In this step, you perform your test and collect data from the results. This data is usually presented in tables and summarized as graphs. Graphs generally depict averages and don't show repeated results or every single data point. Step 7: Draw Conclusions To make a conclusion, you must look at the results of the test and decide whether your hypothesis was supported or rejected. Avoid using the word "prove" in your conclusions. All scientific knowledge is based on tentative or provisional knowledge, nothing is final. Claims made by science are considered to be better or more accepted than others based on the evidence. No knowledge or theory (which embodies scientific knowledge) is final.
Part 2: The Task You will use the scientific method to answer a question about human lung capacity. The volume of air in your lungs can be measured with a spirometer, which traps exhaled air and measures the amount in mL (milliliters). Lung volume for an adult human is about 6000 mL, though not all the space is used for gas exchange. The maximum usable capacity of the lungs is called the vital capacity. There are many factors that could explain variations in the vital capacity of any two individuals. Your task is to use the scientific method to study lung capacity and a hypothesis of your choice. Objectives: To observe natural phenomenon To develop scientific reasoning skills To formulate hypotheses and arrive at conclusions To establish that the most reasonable explanations for natural phenomena are those that are supported by evidence Materials: Spirometer and mouthpieces, calculators, meter sticks or tape measures, other lab equipment can be used, just ask Safety considerations: Students who have respiratory issues should not participate. If you at any time feel lightheaded, discontinue tests. 1. Make an observation have several members use the spirometer. Write your observations on the summary sheet. Was everyone's vital capacity the same or were there variations? 2. Ask a question. Discuss wording for a causal question about your observations, write your question on the summary sheet. 3. Form hypotheses. Come up with as many possible explanations (at least 3) as you can that are answers to your causal questions and write on the summary sheet. Share your hypotheses with the class and decide as a class which one you will test. Make your choice based on what can be tested during class time. Your instructor may guide you through this process. 4. Design the experiment. As a group, discuss ways to test the hypothesis. Try to keep the experiment as controlled as possible and consider you may want to repeat your tests. On the summary sheet, describe your test in detail and identify the independent and dependent variables. Your test may or may not have a control group; if it does the people in your experimental group should differ from your control group by the variable that is identified in the hypothesis. 5. Make a prediction. State what your data should show assuming that your hypothesis is correct. 6. Do the experiment and collect data. Record data on the summary sheet and make a bar graph of your data by using the average vital capacity for each group. 7. Draw conclusions. Remember to restate your hypothesis and clearly indicate whether you support or reject the hypothesis. Write this on the summary sheet. 8. Complete the analysis questions. You may need to take these home as homework. Remember that while you worked in a group for much of this activity, the conceptual understanding (LEARNING) of how the scientific method works is an individual activity.
Name(s) _________________________________________________ Date ______ Summary Sheet: Investigation: What are the Processes of Science? 1. State your observation(s). 2. State a causal questions. 3. List the hypotheses suggested by the class, place a star next to the one that the class decided to test. 4. What test did your group decide upon? Describe your test. a) State the independent variable b) State the dependent variable c) Do you have a control group? If so, what is it. If not, how will you test the hypothesis. d) State your control variables (things that stayed the same between groups) e) What additional considerations were made when designing your test? 5. Make a prediction in the form of IF (repeat hypothesis) THEN (state prediction) statement. 6. Construct a data table with appropriate labels and show the data you gathered. If you are testing the entire class, this may be a large amount of data. Attach a page to this one if necessary. 7. After you collect data, graph the data. Your graph will probably be a bar graph with bars representing averages. The X axis is always the independent variable and the Y axis is the dependent variable.
8. State your conclusion in a full sentence using the proper format. "The hypothesis that (repeat hypothesis) was (supported or not supported.)" Analysis 9. The experiment you did today has some flaws in its design. List other factors that may have influenced your results. Discuss how these uncontrolled variables may have affected your results. 10. Based on your answer in #9, are you more confident or less confident in your conclusion. Explain. 11. If you were given another class period to redesign your test, what would you change? 12. Not all experiments have a control group. Provide at least two examples of studies that would probably not have a control group (you can use this project if it applies.) 13. What type of experiments do have a control group? Give an example of research that would likely require a control group in order to draw valid conclusions.
(AP BIO) Feedback mechanisms maintain a living system’s internal conditions, allowing it to remain alive and functional even as external conditions change, a phenomenon referred to as HOMEOSTASIS. For example, if the oxygen levels in the blood drop, feedback mechanisms will send a signal to the brain to increase the rate of respiration. Mountain climbers often have difficulty breathing because the air pressure is low. Pressure from the atmosphere allows humans to fully inflate the lungs. a) How would feedback mechanisms affect a mountain climber's respiration in order to maintain the body's homeostasis? b) Plan an experiment for an investigation into this phenomenon that includes each of the following: How will the change in an external environment be measured? How will the response of the living system be measured? How will the stabilization of the system's internal conditions be measured? c) What data from your test would show that homeostasis was maintained? What are the limitations of the test?
