S CIENTIFIC M ETHOD How we solve problems

S CIENTIFIC M ETHOD The scientific method is a way to ask and answer questions by making observations and doing experiments. Science is the process of doing this.  Observation: An act of noticing a fact or occurrence What senses do we use to notice facts and occurrences?

O BSERVATIONS V S. I NFERENCES We use our five senses to observe things in nature. We use our brain to make inferences based on these observations.  Inference: A conclusion reached based on evidence (observations) and reasoning

W HAT OBSERVATIONS CAN YOU MAKE ?

S CIENTIFIC M ETHOD It is important for your experiment to be a fair test. A "fair test" occurs when you change only one factor ( variable ) and keep all other conditions the same.  Variable: a factor or item that is changed during an experiment

O VERVIEW OF THE S CIENTIFIC M ETHOD Scientists use the scientific method to search for cause and effect relationships in nature. In other words, they design an experiment so that changes to one item ( the independent variable ) produces a measurable change in another item ( dependent variable ).  Constants: factors that are NOT changed during an experiment  Independent variable: the variable changed by the scientist during an experiment  Dependent variable: the variable being measured that changes as a result of changes to the independent variable

T HE D EPENDENT VARIABLE DEPENDS ON THE INDEPENDENT VARIABLE !!! Example: Various plant foods are applied to tomato plant seedlings. The growth of the tomato plants depends on the plant food used. What are the variables in this experiment? Independent: _______________________________ Dependent: ________________________________ What other factors could affect plant growth? In order for this to be a fair test of plant foods, these other factors must be held constant.

B RAIN P OP V IDEO C LIP Scientific Method Video Clip

S TEPS OF THE SCIENTIFIC METHOD Ask a Question The scientific method starts when you ask a question about something that you observe. This may be identifying an effect (or problem) that has a yet to be identified cause. In order for the scientific method to answer the question it must be about something that you can measure, preferably with a number.  Control : A standard to which your results may be compared

S TEPS OF T HE SCIENTIFIC METHOD Do Background Research Rather than starting from scratch, scientists use library and Internet research to help find the best way to do things and to avoid mistakes from the past.

S TEPS OF T HE SCIENTIFIC METHOD Construct a Hypothesis: A hypothesis is an educated guess about how things work. "If _____ [I do this] _____, then _____ [this] _____ will happen.”  Hypothesis: a prediction about cause and effect based on research.

S TEPS OF T HE SCIENTIFIC METHOD Test Your Hypothesis by Doing an Experiment Your experiment tests whether your hypothesis is true or false. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions constant (the same). You should also repeat your experiments several times to make sure that the first results weren't just an accident.

S TEPS OF T HE SCIENTIFIC METHOD Analyze Your Data and Draw a Conclusion Once your experiment is complete, you collect your observations and analyze them to see if your hypothesis is true or false. Scientists often find that their hypothesis was false, and in such cases they will construct a new hypothesis starting the entire process of the scientific method over again. Even if they find that their hypothesis was true, they may want to test it again in a new way.

S TEPS OF T HE SCIENTIFIC METHOD Report Your Results To complete your experiment you will communicate your results to others in a final report and/or a display board. Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster at a scientific meeting.

Draw this in your notebooks with colors!

S CIENTIFIC THEORIES AND LAWS  Scientific theory: An explanation or model backed by results from many experiments. A hypothesis becomes a theory if it is supported by evidence over time.  Scientific law: A rule that describes the behavior of something in nature that just “is.” An example is the law of gravity.

E ARTH S CIENCE Geology Meteorology Oceanography Astronomy

GPS (G LOBAL P OSITIONING S YSTEM ): A system that triangulates a person’s position on Earth by receiving signals from orbiting satellites. By comparing how far the person (receiver) is from each satellite, the person’s location is determined and displayed. VIDEO!!!

V OCABULARY R EVIEW  Observations  Inference  Constant  Independent Variable  Dependent Variable  Control  Hypothesis  Scientific Theory  Scientific Law  Global Positioning System Define and turn in using the paper cut method!