AN INTRODUCTION TO WHAT GRAPHS ARE AND HOW TO MAKE THEM

Great Graphs

A GRAPH IS A PICTURE OF YOUR DATA

Graphs and charts are great because they communicate information visually. They take lots of data (numbers) and represent it visually

GREAT GRAPHS

Graphs and charts are used very often in newspapers, magazines and SCIENCE to show information

With graphs, data we collect is easily interpreted and makes sense

First we put all the data that is collected into a DATA table.

How do we start?

What does a data table look like?

A data table has 6 parts

Parts of a DATA TABLE

1A descriptive title

2A constant (uniform standard of measure)

3A variable (describing what information is to be collected during the experiment)

4Units identifying how the variable and constant were measured

5Data that has been collected in ordered pairs

6All data herded into neat, little boxes

Time (min) 0 2 4 6 8 10 12 14

Temp (˚C) 0 0 2 2 4 10 20 30

Heating of Water1

2

3 4

5

6Graphs are made from the information

found in the data table!

THEN….

Second, hand drawn graphs are ALWAYS done on graph paper

•You can also make them on a computer

There are three main types of graphs

*Bar Graph*Line Graph* Pie Chart

ALL GRAPHS…

All Graphs have a TITLE The Title should tell us about what kind of data we will

see on the graph The title is centered at the top of the graph

Title

ALL GRAPHS…

X axis: The horizontal axis (across the page)

Usually this shows the independent variable

Y axis: The vertical axis (up and down the page)

Usually this shows the dependent variable

ALL GRAPHS…

Lables: Graphs must have labels on the X axis and Y axis.

All lables must have UNITS for the data (ex: cm, seconds, minutes, meters)

ALL GRAPHS…

Numerical data: is listed on the line of the axis (ex: 0 is ON the bottom line)

BAR GRAPH

 

* Bar Graphs are used to compare different things

* Bar Graphs are used to show discontinuous data (that is data that is not connected (example: graph showing who likes different fruit)

* Bar graphs can be displayed vertically (up and down) or horizontally (side to side)

BAR GRAPH SIDE NOTES

Must have x and y axis labeled

Must have a title Neat, organized bars Appropriate use of

space

ALWAYS READ THE STORY!!!

EXAMPLE: The Purple Martin….. The purple martin is a small bird that

eats mosquitoes and other insects. To catch its favorite meal, the purple martin glides through the air where mosquitoes fly, too. The bar graph below shows the number of insects caught by a group of purple martins one day during the afternoon and evening.

Example

4:00-4:30 4:30--5:00 5:00-5:30 5:30-6:00 6:00-6:300

2,000

4,000

6,000

8,000

10,000

12,000

Y axis

label

TITLE

X axisaxis titleX axis

UNITS

Time of day

(HOURS)

Number of Mosquitoes

MOSQUITOES CAUGHT

EXAMPLE QUESTIONS

1. How many insects were caught during each time period?4:00-4:30 ____________

4:30-5:00 ____________

5:00-5:30 ____________

5:30-6:00 ____________

6:00-6:30 ____________

EXAMPLE QUESTIONS 2. How many more insects were caught between

5:00-5:30 than between 5:30-6:00? ________________  3. How many fewer insects were caught between

6:00-6:30 than between 4:30-5:00? __________________

4. How many insects were caught between 4:30-6:00? ______________

  5. Were more insects caught between 5:30-6:00 or

between 6:00-6:30? ________________  6. How many insects were caught in all? _____________

7. What is the average number of insects caught during each half hour period? ____________

LINE GRAPH

Line Graphs are used to demonstrate change over

time.

•Line graphs are used to demonstrate continuous data

(that is data that is connected, such as over of period of time)

LINE GRAPH

Must label x and y axis

Must have a title Uses a line to

connect points

LINE GRAPH

Line Graphs consist of data points connected together with a line this shows the trends in the data

collected  X axis (independent variable) usually

shows the units of time such as hours, seconds, days, weeks etc.

Y axis (dependent variable) usually shows the units of measurement

UNITS

X axis label

Title

Y axis label

Days of the Week

Feet Traveled

MONDAY

TUES

DAY

WED

NESDAY

THURSD

AY

FRID

AY

SATU

RDAY

SUNDAY

0

500

1000

1500

2000

2500

3000

3500

4000

How Far Casey Skated

EXAMPLE QUESTIONS

1. How much farther did Casey skate on Wednesday than on Thursday? ____________

2. What day did Casey skate the farthest? ___________

3. How many feet did Casey skate in all on Saturday and Sunday? ___________________

4. What was the average number of feet Casey skated each day? (round to the nearest whole number) ______________

5. If Casey skated twice as far as she did on Wednesday, how far will she skate? ____________

CIRCLE OR PIE CHART

•Pie Charts are most often used to compare percentages. The entire “pie” is equal to 100% and the size of each “pie slice” corresponds to a percentage amount

* Pie Charts also show proportions

CIRCLE OR PIE CHART

The whole pie is 100%

Each piece of the pie is a fraction of 100%

All pieces must start in the center or the circle

WHAT’S A LEGEND?

The Legend The legend tells what each slice represents.

Just like on a map, the legend helps the reader understand what they are looking at. This legend tells us that the blue slice represents money spent on non-instruction, the green slice represents money spent on support services, and the orange slice represents money spent on instruction activities.

***A legend can be used in any graph that has more than one set of data.***

EXAMPLE: A large machine at the mall holds 900 gum balls in six flavors. The pie chart shows how many gumballs there of each flavor.

Flavor QuantityBlueberry 153Licorice 297Grape 90Cinnamon apple

180

Green apple 45Spearmint 135

153

90

180

45

135

297

Gumball Flavors

BlueberryGrapeCinnamon appleGreen appleSpearmintLicorice

licorice

blueberry

grape

cinnamon ap-ple

green apple

spearmint

EXAMPLE QUESTIONS 1. How many gumballs taste like green apples?

_________ 2. What is the total number of gumballs that

taste like apples? _____________________ 3. Which flavor has the most gumballs?_________ 4. Why do you think this flavor has the most

gumballs in the machine?________________________ 5. Write a fraction to show how many of the

gumballs are cinnamon apple flavor. (Write the fraction in lowest terms) _____________________________

6. What percentage of the gumballs are cinnamon apple? _____

So what do we do with the information that is on a graph anyway???

We get the information for the graph from the DATA TABLE

We use the graphs to help us DRAW CONCLUSIONS FROM THE RELATIONSHIPS IN THE DATA.

WHAT’S WRONG HERE?

No title or labels!!!!

WHAT’S WRONG HERE?...

No titles, no labels and circle does not equal 100%!!

NOW THAT YOU KNOW WHAT GRAPHS ARE AND

HOW TO CREATE THEM YOU WILL PRACTICE CREATING YOUR OWN! GOOD LUCK!