Aim: How to plot or graph data
What is the Scientific Method? “The Road to Knowledge”
•The Scientific Method is a method of procedure scientist use consisting in observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
•It is a way to ask and answer scientific questions by making observations and doing experiments
•It is a dynamic process; meaning, there is no definite order to the steps in the scientific method. Scientist jump from one step to another when testing a hypothesis, even formulating a new one.
Steps to the Scientific Method•Making observations
•Coming up with a hypothesis and testing it. A hypothesis involves developing an idea or set of ideas that might explain our observations
•Collect and analyze data.
•Check results in experiment against your hypothesis: “Do your results agree with your hypothesis?”
•Start over if you need to.
Graphing and Analyzing Data•Identify dependent and independent variables•Dependent variable – the variable that is being observed during an experiment. •Independent variable – the variable that is being changed during an experiment
Graphing and Analyzing Data Cont.•Labeling the graph• Title the graph• Label the y-axis (dependent variable) and x-axis (independent variable)
•Direct relationship; “as one variable increases, the other variable increases” or “as one variable decreases, the other variable decreases”•Indirect or inverse relationship; “as one variable increases, the other variable decreases” or “as one variable decreases, the other variable increases”
Determining slope of best-fit line 1. Prepare a scatter plot of the data. 2. Using a ruler, draw a straight line (best-fit line) so that the plotted points are as close to the line as possible.
3. Find two points that you think will be on the "best-fit" line.
4. We are choosing the points (1.4, 100) and (3.4, 300). You may choose different points.
5. Calculate the slope of the line through your two points. , x1= 1.4 and x2= 3.4
Y1 = 100 and Y2= 300
Length (cm)Mass (g)5.25 0.48.25 0.6
18.75 1.222.25 1.424.75 1.6
24.8 1.616 1.1
9.2 0.723 1.4
11.5 0.83.2 0.12.5 0.05
0 5 10 15 20 25 300
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Length (cm)
Mas
s (g)
Mass versus Length of Spaghetti