How do we do Science?

Reminder: What is Science? The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions Science is an organized way of using evidence to learn about the natural world

Reminder: What is Science? Science involves gathering data through observation ◦ We create a research question about the natural world inspired by observation Scientists propose hypothesis (a scientific explanation for a set of observations) ◦ Hypothesis must be able to be tested ◦ New hypothesis must be considered if observations and data demand it

The Scientific Method Scientists use the scientific method to answer questions about the natural world ◦ State the Problem ◦ Form a Hypothesis ◦ Design and conduct controlled experiments to test the hypothesis ◦ Make observations and collect data ◦ Draw conclusions based on results

Scientific Method Science involves gathering data through observation ◦ We state the problem we wish to learn more about Scientists propose hypothesis (a scientific explanation for a set of observations) ◦ Hypothesis must be able to be tested ◦ New hypothesis must be considered if observations and data demand it

Testing a Hypothesis How do we commonly test a hypothesis? Experiments that generate data ◦ The factors that can change are variables ◦ One item is changed (the manipulated variable) while everything else is controlled to be the same ◦ The variable that is observed is the responding variable Which one of us is changing?

Gather Data, Make Conclusion Gathering data usually involves measuring (results of the experiment) Data should either refute or support your hypothesis- conclusion ◦ Both are valuable ◦ Disproving your hypothesis is not “bad” Experiments are then typically replicated to ensure the results/conclusions are accurate

Is One Experiment Enough to Prove Something? If we give 10 people a flu vaccine and none of them become sick, does that prove that you can’t get the flu after the vaccine? A key part of proving something scientifically is being able to replicate your experiment with the same results (or at least the same conclusions)

What if we can’t do an experiment? Can we do an experiment to study how animals interact with one another in the wild? ◦ Can we control everything in the wild? ◦ Researchers observe the animals without disturbing them with field studies

What if we can’t do an experiment? Can we do an experiment on whether a chemical causes cancer in humans? ◦ Study those who were exposed versus people who were not Futurama TM and © 2011 Twentieth Century Fox Film CorporationFuturama TM and © 2011 Twentieth Century Fox Film Corporation. All Rights Reserved

Developing a Theory As evidence piles up, scientists may begin considering a hypothesis a theory ◦ A theory is not considered absolute truth, but it does have a large amount of evidence supporting it ◦ If new evidence begins to be uncovered that a theory is incorrect it can be replaced or altered (Spontaneous generation versus life comes from life)

Spontaneous Generation Experiment

Scientific Method Video GQmDqY GQmDqY