Scientific Method Scientific Method Step 1 Pose a question or a problem. The research question is the single most important part of the scientific method. Every part of your project is done to answer this question. The research question is sometimes formed as a statement and is called the "Problem" or "Problem Statement." Does temperature affect how many times a cricket chirps? Step 2 Develop a Research Plan A research plan involves finding background information about your topic. Why do crickets chirp? Step 3 Hypothesis A hypothesis is a answer or prediction about the outcome of an experiment. A hypothesis is written in an “If..., then..., because...” statement Example If we increase the temperature of a crickets environment, then the crickets will chirp more because…….. Step 4 Design an Experiment An experiment is a series of trials that are done to support or refute (disprove) a hypothesis. Design a controlled experiment • In a controlled experiment, only one condition is changed at a time. • All variables are kept constant except the one you are testing. How to Design an experiment with two groups. The experimental group is the group that contains the variable being tested. The control group is the group that is the normal, or does not contain the variable being tested. Constants Constants are factors in an experiment that are kept the same and not allowed to change. Examples 1. 2. 3. 4. 5. Age of crickets humidity Gender of crickets Environment Food Two Types of Variables Independent variables that are purposely changed or manipulated in an experiment the factor that you wish to test usually expressed after the word “if” in the hypothesis could be thought of as the “cause” in a cause and effect relationship Example Change in temperature Dependent the factor you measure to gather results variables that may change as a result of the independent variable usually expressed after the word “then” in the hypothesis could be thought of as the “effect” in a cause and effect relationship Example Number of chirps Identify the Variables independent variable 1. If a student chooses to not study, then they will earn a poor grade. dependent independent variable variable 2. If you drink Gatorade before a soccer game, then you will score more goals. dependent variable independent variable 3. If you increase the mechanical advantage of a pulley system used to move an object, then the input force becomes less. dependent variable 2 Types of Data Quantitative data consisting of numbers Example Sunlight leaves held on average 21 more pennies than leaves that were in the shade. Qualitative data consisting of verbal descriptions or information gathered using scales without numbers Examples Leaves that were in the shade were a lot stronger than leaves that were in the sun. Conclusion Based on the Data collected during the experiment, you can draw conclusions about the outcome of your experiment. Was your hypothesis correct? Some characteristics of a good experiment are: Can be repeated by anyone and get the same results. Have a large sample size. Are peer reviewed. Does not have to agree with the hypothesis. Is objective (unbiased). Mnemonic Devices Q ueen - question R achel - research H opes - hypothesis E very - experiment C oward - collect data G ains - graph/analyze data C ourage - conclusion