Chapter 2
Data in Science

Section 1: Tools and Models

Vocabulary mass amount of matter in an object volume amount of space something occupies measure of the size of an object in a 3D space density amount of a matter in a given volume
D = mass/volume D= m/v

Vocabulary temperature measurement of how hot/cold substance is model representation of object or a system

Vocabulary theory a system of ideas that explains many related observations and is supported by a large body of evidence
Law descriptive statement or equation that reliably predicts events under certain conditions

Tools in Science
Need to be accurate use the proper tool

Making Measurements
International System of Units aka “metric system” based on multiples of 10

Making Measurements
Length meter (m)
Mass kilogram (kg)
1 kg = 2.2 lbs volume liter ( L )
1 mL = 1 cm³

Density ratio of mass to volume amount of matter inside

Models in Science used to simplify complex concepts physical sketch or scale train mathematical weather economics conceptual big bang theory

Models in science
Right size models help to make large items easy to see models brings to life unseen concepts sound waves
Limitations only as good as information put into it

Making Scientific Progress
Models: summarize info tool for communication

Making Scientific Progress
Scientific Theory based upon repeated tests of a hypothesis explains and predicts
Law summary of multiple experiments tells you how things work stronger than theory

Section 2: Organizing Data

Vocabulary independent variable dependent variable axis

Vocabulary independent variable the factor that is deliberately manipulated dependent variable the factor that changes as a result of the independent variable being changed

Vocabulary axis one of two reference lines that mark the borders of a graph.
Dependent Variable
Independent Variable

Creating a Data Table organization is key gather data from research data table with 2 columns independent variable goes on x-axis factor that is changed in an experiment dependent variables goes on y axis changes as a result of the independent variable

Creating a Data Table
Controlled parameter factors that stay constant throughout the experiment variable parameter factors that change in an experiment

Creating a Graph highly visual easy format to see information
Axis x-axis is horizontal x-axis is independent variable y-axis is vertical y-axis is dependent variable

Creating a table
Range the extent of each variable subtract the smallest value from the largest value

Range: x axis:
6 days- 1 days = 5 days y axis
65 deg - 40 deg = 25 degrees

Creating a Table
Scale each axis has its own scale factor
Data Points plot data points first then find line of best fit captures the most data linear

Creating a Table
Labels!
each axis and a title

Patterns Shown by Graphs trend direction or pattern of data straight line = linear curved line = non-linear

Patterns Shown by a Graph
Positive or Negative Relationship

Sec 3: Analyzing Your Data

vocabulary
Mean
Median
Mode
Slope

Vocabulary mean
- the number obtained by adding up the data and dividing by the sum of the occurances.
- aka… AVERAGE
- median
- middle number when data arranged in order from lowest to highest

Vocabulary mode
- most frequently occurring value slope
- measure of the steepness of a line
- ratio of rise over run

Why Mathematics?
• Math is international language
• measures properties
• exact
• patterns can be seen

Accuracy of Data
• make sure tools are functioning correct
• make sure you are using tool properly

Reproducing Data
• data must be reproducible in future experiments
• verifies the results

Describing Data Sets
 mean
 average
 find the mean of
 26, 20, 15, 27

Describing Data Set
 median
 the middle number

Describing Data Set
Mode
➔ number that appears most often

Slope of a Line
➔ rate of change
➔ slant of a line
◆ rise over run
◆ change of y values divided by the change of x values

Slope of a Line
Positive, Negative, or horizontal lines