Scientific Method

Scientific Method Steps

• State the problem.• Research the problem• Make a hypothesis.• Conduct the experiment.• Collect/analyze data.• Draw a conclusion.• Share your results

State the problem

• Problems arise from observations we make

Observations

• Observations: We use our senses to gather information about the world around us.

Hypothesis

• An educated guess• A prediction• Use “If”, “then” format

– We predict that if we drop a ball from a higher height, then it will bounce higher.• “If” is the Independent variable.• “Then” is the Dependent variable.

Experiment

• Must have a procedure– Step by step directions

• Must have only one variable– Thing that changes in experiment

• Everything else must be kept the same – Controls

Collect/Analyze Data

• Make a data table to collect results of experiment

• Make a graph (if possible)

Draw a Conclusion

• Use the data to either prove or disprove your hypothesis

Theory

• Has a very different meaning in science than in everyday life.

• “The detective has a theory about who robbed the bank.” This is a guess.

• When scientists use the word theory it is not used as a guess.

Theory defined

• An explanation based on many observations during repeated experiments that is valid only if:– it is consistent with observations – makes predictions that can be tested – It is the simplest explanation.

• A logical, time tested explanation for events that occur in nature.

Graphing

• The visual characteristics of a graph make trends in data easy to see.

• One of the most valuable uses for graphs is to "predict" data that is not measured on the graph.

Graphing Steps

• Identify the Variables

INDEPENDENT VARIABLE

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Graphing Steps

• Identify the Variables• Determine the scale

INDEPENDENT VARIABLE

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Graphing Steps

• Identify the Variables

• Determine the scale

• Number and label each axis

• Plot the points• Draw the graph

INDEPENDENT VARIABLE

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Graphing Steps

• Identify the Variables

• Determine the scale

• Number and label each axis

• Plot the points• Draw the graph• Give graph a title

INDEPENDENT VARIABLE

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TITLE

Identify the Variables

– Independent Variable - (the thing you changed)

Goes on the X axis (horizontal) Should be on the left side of a data

table.

– Dependent Variable - (changes with the independent variable)

Goes on the Y axis (vertical) Should be on the right side of a data

table.

Scale

– Determine a scale,(the numerical value for each square),that best fits the range of each variable.

– Spread the graph to use MOST of the available space.

Label Axis's

• You need to tell everyone reading your graph what the graph means.

• Be sure to include units.

Plotting

• Plot each data value on the graph with a dot. You can put the data number by the dot, if it does not clutter your graph.

Drawing

–Draw a curve or a line that best fits the data points.

–Most graphs of experimental data are not drawn as "connect-the-dots".

Title• Your title should clearly tell what

the graph is about.

• If your graph has more than one set of data, provide a "key" to identify the different lines

Interpolation

• Interpolate: predicting data between two measured points on the graph.

Extrapolation

• Extrapolate: extending the graph, along the same slope, above or below measured data.