Scientific Method

What is scientific inquiry? The ways in which scientists study the natural world… …and propose explanations based on the evidence they gather

Scientific Method What is scientific inquiry? If you have ever tried to figure out why your iPod or computer is not working… …you have used scientific inquiry

The Scientific Method Begins with a problem or question about an observation

Scientific Method Some questions cannot be answered by scientific inquiry Why has my iPod stopped working? What kind of music should I listen to on my iPod?

Scientific Method This is a scientific question because it can be answered by making observations and gathering evidence Why has my iPod stopped working?

Scientific Method This question has to do with personal opinions or values and is not a scientific question What kind of music should I listen to on my iPod?

Scientific Method Is running a better sport than swimming? Which of the following questions can be answered by scientific inquiry? Does running make your muscles stronger than swimming? Which brand of running shoes looks best?

Scientific Method It is a really hot summer night You notice that the crickets are chirping louder than usual Questions come from experiences or observations you have

Scientific Method Begin posing questions… Why are the crickets chirping louder tonight? ?

Scientific Method Individual/Group Activity Posing Questions

Scientific Method After choosing a topic to investigate and writing a testable research question Collect Information

Scientific Method Collect Information Determine Variables

Scientific Method What are variables? Variables are all the factors that can change in an experiment, possibly affecting the results

Scientific Method Variables It is important that you test only one variable at a time

Scientific Method Variables This way you can be sure it’s the one thing that caused the results

Scientific Method In any Scientific Investigation there are 3 types of Variables Independent Dependent Controlled

Scientific Method The Independent (Manipulated) Variable The ONE factor or condition that is intentionally changed by the experimenter

Scientific Method The Dependent (Responding) Variable The factor or condition that is affected by the independent variable

Scientific Method The Controlled Variables All the factors or conditions that must be kept the same in an experiment

Scientific Method The M&M Example Will M&M color dissolve faster in water or in vinegar?

Scientific Method The M&M Example What is the Independent Variable? Type of liquid

Scientific Method The M&M Example What is the Dependent Variable? Time it takes for color to dissolve

Scientific Method The M&M Example What are the controlled variables? Color of M&M Amount of liquid Type of M&M

Scientific Method Individual/Group Activity Variables in Experiments

Scientific Method Forming a Hypothesis What is a Hypothesis?

Scientific Method Forming a Hypothesis A hypothesis is a special type of prediction that is a possible explanation for a set of observations or an answer to a scientific question

Scientific Method Forming a Hypothesis When you form a hypothesis you are trying to answer your research question BEFORE you experiment

Scientific Method Then you carry out investigations and gather evidence to prove or disprove your hypothesis Forming a Hypothesis

Scientific Method

Developing a Hypothesis Pose question - Do crickets chirp more when the temperature is higher? Hypothesis – cricket chirping increases at higher air temperatures

Scientific Inquiry Developing a Hypothesis Remember - A hypothesis is a possible explanation for a set of observations or answer to a scientific question

Scientific Inquiry Developing a Hypothesis Important! A hypothesis is not a fact. It is one possible way to explain a group of observations

Scientific Inquiry Developing a Hypothesis Maybe you had more windows open that night so the crickets sounded louder Maybe there were more crickets around that night

Scientific Inquiry Designing an Experiment to test your hypothesis Hypothesis – cricket chirping increases at higher air temperatures How will you design your experiment?

Scientific Inquiry Designing an Experiment to test your hypothesis Counting how many times crickets chirp when the temperature is high How will you know how many times the crickets would chirp at a lower temperature?

Scientific Inquiry Designing an Experiment to test your hypothesis You need to observe crickets at different temperatures – the temperature is a variable

Scientific Inquiry Designing an Experiment to test your hypothesis What is a variable? Variables are factors that can change during an experiment

Scientific Inquiry Designing an Experiment to test your hypothesis Examples of Variables in your experiment would be… Type of crickets Type of container ?

Scientific Inquiry To test your hypothesis you purposely change one variable and make sure all other variables stay the same Controlling Variables What variable are you purposely changing in this experiment?

Scientific Inquiry Controlling Variables The temperature You need to observe crickets at different temperatures

Scientific Inquiry Controlling Variables The one variable that is purposely changed to test a hypothesis is called… The Manipulated Variable (also known as the independent variable)

Scientific Inquiry Controlling Variables The factor that may change in response to the manipulated variable is called… The Responding Variable (also known as the dependent variable)

Scientific Inquiry Controlling Variables In this experiment the manipulated variable is… The air temperature In this experiment the responding variable is… The number of cricket chirps

Scientific Inquiry Controlling Variables By keeping all variables the same (CONTROLLED) except for temperature… Identical containers Identical thermometers Identical leaves Identical crickets (type and number)

Scientific Inquiry Controlling Variables …and manipulating only the variable of temperature… Container 1 = 15 C Container 2 = 20 C Container 3 = 25 C o o o

Scientific Inquiry Controlling Variables …you will know that any difference in cricket chirping must be due to temperature

Scientific Inquiry An experiment in which only one variable is manipulated at a time is called… A Controlled experiment Controlling Variables

Scientific Inquiry Setting up a Controlled Experiment Suppose we decide to test the crickets at 15 C in the morning and the crickets at 20 C and 25 C in the afternoon… Is this a controlled experiment? o o o

Scientific Inquiry Setting up a Controlled Experiment No! This experiment would have 2 manipulated variables – temperature and time of day Would increased chirping be due to… Temperature difference? Time of day?

Scientific Inquiry Forming Operational Definitions A statement that describes how to measure a particular variable or define a particular term is called… An Operational Definition

Scientific Inquiry Forming Operational Definitions For our experiment we need an operational definition of how we are going to time and count the “chirps”

Scientific Inquiry Collecting and Interpreting Data Data – the facts, figures, and other evidence gathered through observations

Scientific Inquiry Forming Operational Definitions A statement that describes how to measure a particular variable or define a particular term is called… An Operational Definition