REPRESENTING DATA

Chapter 1

VOCABULARY Bar Graph –

uses horizontal or vertical bars to represent data

Line Graph – uses a line to show changes in data over time

Circle Graph – represents data using sections of a circle; sum of the circle adds up to 100%

Pictograph – shows data

using pictures/symbols

Double Bar Graph – compares two sets of data across categories using vertical or horizontal bars

Double Line Graph – uses two lines to represent changes in two sets of data over time

CONTINUED

Interval/Range – The spread between the smallest and the largest numbers in a range of numbers. (i. e. 0, 5, 10, 15, 20 . . . or 0, 2, 4, 6 8 . . .)

Trend – The general direction in which the line graph is going

Distort – to change the appearance or twist the meaning of a graph to mislead the reader.

AXIS

In-Class Assignment #1Create a bar graph using data from our our class,

8E.

OPTIONS: 1) Pets 2) Favourite Colour 3) Favourite Sport

STEPS: Select an option Create three to four categories/options Collect data Design your graph – include titles as shown in the

example Add colour for visual clarity

ExampleTitle your grap

h

Title your Y axis

Title your X axis

Set your intervals/range

Title the

categories you

are compari

ng

1.1 – Advantages & Disadvantages

of Different GraphsCompare information from different graphs

Identify the advantages and disadvantages of different types of graphs

What is each graph the best for?

Bar graphs are best for comparing data across categories.

Circle graphs are best for comparing categories to the whole using percents.

Line graphs are best for showing change over time.

Pictographs are best for comparing data that can be easily counted and represented using symbols.

PG. 14 - #7 a

Examples of a Double Bar & Double Line Graph

Double Line Graph Remember to

label your x and y axis and title your graph. * This graph is missing a title.

Include a key that tells what each line represents. Ex. Blue = Tom Purple = John

Double Bar Graph Remember to

label your x and y axis

and title your graph.

Include a key that tells what each bar represents. Ex. High = red Low = Blue

1.2 Misrepresenting Data Explain how the size of intervals on a graph

could be misleading

Explain how the visual representation of a graph could misrepresent data

Explain how the size of bars on a graph could be misleading

Identify conclusions that do not agree with a given data set or graph and explain the misrepresentation

Misleading Graphs – Three Ways1. Distorting the scale by using a break in the y-axis

Misleading Graphs

2. Distorting the size of the visual by making a symbol appear larger than others

Pg. 21 – Show You Know

Misleading Graphs3. Distorting

the size of the bars in a bar graph by making the bar wider or making a bar appear 3-D

QUESTION You see two

different examples of graphs showing healthy choices sold at the cafeteria.

If you had to

convince Mr. Wight that we should continue selling healthy choices, which graph would you choose?

ANSWER If I had to convince Mr. Wight that we should continue selling healthy choices in the cafeteria, I would choose the line graph because it shows that the trend is increasing and clearly shows that people are buying more healthy foods.

Distort each of the graphs, so that your information looks even MORE impressive. You cannot change the data, but you can change the graphs.

1.3 Critiquing Data Presentation

Explain how the graph is used to represent the data from a given situation

New Vocabulary Terms:

Stacked Bar Graph – has bars stacked instead of side by side

Important Factors When Critiquing a Graph

1) Graph Type: is it the best choice for displaying the data?

2) Graph Format: does its design represent the data accurately? (no distortions)

3) Graph Usefulness: is it informative and does it support a claim/argument?