Tables and Graphing

Displaying Data

• Sometimes it is easier to read data in a visual format. This can come in the form of tables, graphs, charts, etc.

• Recall that there are two types of data:– Qualitative: descriptions– Quantitative: numbers

Tables

• Tables organize data into categories. They can include qualitative or quantitative data.

Grade # ofMales

# of Female

9th 305 298

10th 295 300

11th 298 305

12th 290 310

Trait Before Reaction

After Reaction

Smell Rotten eggs

No scent

Color Yellow White

State Solid Liquid

Pie Charts

• Pie charts use fraction and/or percentages to show portions of a whole.

• All pieces should add up to 100% or 1 whole.

Regions Causing Global Warming

Bar Graphs / Histograms

• Bar graphs / histograms show the frequency of something. – For example, it can show the number of people

who have a certain height, birthday month, age group, etc.

Multiple Bar Graphs / Histograms

• Sometimes multiple bar graphs / histograms can be combined on a single visual for comparison. Each set of data is distinguished by different colors or designs.

Line Graphs

• Line graphs show change over time. You must plot points on a graph and then carefully connect the points. – Line graphs do not necessarily have straight lines.

Sometimes they are curved or even sporadic in shape.

Multiple Line Graphs

• Sometimes multiple line graphs can be combined on a single visual for comparison. Each set of data is distinguished by different colors or designs.

How Do I Plot Points on a Line Graph?

• On a line graph, the independent variable (x) is on the horizontal axis.

How Do I Plot Points on a Line Graph?

• On a line graph, the dependent variable (y) is on the vertical axis.

How Do I Plot Points on a Line Graph?

• You must then determine how much each line / marker on your axes will be worth. – For example, if you are counting up by 1’s, each

line would count as 1 unit.

How Do I Plot Points on a Line Graph?

• The intersection of the x and y axis is called the origin. It means x = 0 and y = 0.

• Positive numbers on the x-axis are to the right of the origin. Negative numbers are to the left.

• Positive numbers on the y-axis are above the origin. Negative numbers are below.

How Do I Plot Points on a Line Graph?

• Since scientists mostly deal with positive numbers, in this class, we will USUALLY focus on the first quadrant.

• You must also determine how much each line will be worth. For example, if each line counts as 1, then every line past the origin will be 1 unit more than the previous one.

How Do I Plot Points on a Line Graph?

• When time is used, it is almost always the INDEPENDENT variable (x), so it is labeled on the horizontal axis. The DEPENDENT variable is on the vertical axis (y). – In science, time is almost ALWAYS on the x-axis!!!

How Do I Plot Points on a Line Graph?

• When you have your data, you may write each point as a coordinate (x,y). The x coordinate tells you how far left or right from the origin while the y coordinate tells you how far up and down.

How Do I Plot Points on a Line Graph?

• After you plot your points, you must connect the dots. MAKE SURE YOU CONNECT THEM IN ORDER! – Sometimes it is easiest to connect the dots AS you

plot each point.