Transcript Document

Weather - it’s all
around us and it’s
always changing.
This makes it a
great resource for
gathering and
organizing data
with graphs.
Graphs help us organize information and data in
an understandable way. In today’s “New Times”
we are surrounded by data, from sports statistics
to politics to numbers presented in science
textbooks.
Graphs “are the visual
representations that
focus on the relations
between the ‘objects’
of representation in
terms of a part-whole
structure.” Koulaidis (p.1998)
What are we trying to teach our students?
1. Collect and organize
appropriate data
2. Represent the data graphically,
by selecting the appropriate
graph
3. Read and interpret graphs
4. Evaluate and analyze
information presented in graphs
that are found in textbooks,
newspapers, digital media, etc.
Look for intent behind the
graphic representation of the
data.
When students make graphs from data they collect,
graph interpretation is easier and more interesting
because it is based on actual experience with the
numbers involved.
The experience of interpreting their own graphs gives
students the skills to interpret graphs made by others.
Children begin by
• recording data,
• computing the range of data (the difference between
• two sets of data to give a sense of how “spread out” they are), and
• finding the central tendency (mean) to get an idea of a typical value.
Day
Outside
Temp
(ºF)
Inside
Difference
Temp (ºF) (Out minus In)
(ºF)
1
80ºF
72ºF
8ºF
sunny
2
71ºF
71ºF
0ºF
cloudy & rain
3
86ºF
73ºF
13ºF
windy
4
89ºF
70ºF
19ºF
sunny
5
79ºF
69ºF
10ºF
cloudy
6
95ºF
80ºF
15ºF
broken a/c
Notes
How do we help students decide which type of
graph is best for the data?
In the same way that educators use
concept maps or graphic
organizers, chapter outlines,
webbing, and structured overviews
to help students navigate text, so
can graphs and charts be used as
tools to organize and present data.
•
•
•
•
Circle map
Double bubble
Tree map
Flow map
Dealing with Data
Line Graphs
Pie Charts
Bar Graphs
Organizational Charts
Column Graph
Bar Graph
100
7
90
6
70
60
Series 1
Series 2
50
40
30
Temperature
Temperature
80
5
Series 2
Series 1
4
3
20
2
10
1
0
1
2
3
4
5
6
7
0
20
40
Days
80
100
Days
Line Graph
Area Graph
100
100
90
90
80
80
70
70
60
S eries 1
S eries 2
50
40
30
Temperature
Temperature
60
60
40
30
20
20
10
10
0
S eries 1
S eries 2
50
0
1
2
3
4
Days
5
6
7
1
2
3
4
Days
5
6
7
Vocabulary Needed for
Decoding Graphs
•Key/legend (symbols)
•Axes (X, Y and Z)
•Gridlines
•Scale
•Data Labels
•Data Table
•2 Dimension
•Variables and their relationships to each other
Does the scale make a difference
in how you react to the data?
Do the graphs below show the same information?
Do the pictures suggest the same idea?
Is one graph misleading?
Temperatures Plummet
100
96
90
94
80
92
70
60
50
Series 1
40
30
20
Temperature (ºF)
Temperature (ºF)
Temperatures Stable
90
88
Series 1
86
84
82
80
10
78
0
1
2
3
4
Days
5
6
7
1
2
3
4
5
6
Days
Does the line graph tell you anything about the temperatures in between
the times the readings were taken?
7
Where in the
World is All the
Water?
Students were
asked to guess
what part of the
total amount of
water on Earth
(unchanged since
when the Earth
was formed) is in
the oceans, ice,
groundwater,
atmosphere
(clouds) and
lakes & rivers.
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
The students then graphed
their predictions against
the actual amounts,
dramatically illustrating
their misconceptions about
Earth’s water sources.
Pie Charts
Distribution of Water in the World
Where in the World is all the Water?
1000
900
mls of Water
800
700
600
1
S eries 1
S eries 2
500
400
2
3
4
300
5
200
100
0
1
2
3
4
5
Location of W ater
1 = Oceans
3 = Groundwater
2 = Ice water
4 =Atmospheric water
5 = Lakes & River
Back to temperature…
From simple
to…..
… complex!
Note: a example of nominalization used in the context of analyzing this type
of data is “rate of change of temperature”
Clues that something is “fishy” about a graph:
1. The axis should begin
with zero so that the
measurement scale is
shown whole.
2. If one of the axes is not
labeled, you do not
really know what is
being displayed.
3. The numbers are
identified by their units.
4. The X to Y axis scaling
is not fair, i.e. one axis
has been stretched out.
Proportion of Page comprised of Images
versus Words
High
Image
High Image.
Low Word
Elementary
School
High Image.
Moderate
Word
Middle
School
Moderate Image.
High Word
High
School
Low
Image
Low
Word
High
Word
Juggling 2 variables at once
What does this graph tell us?
Do you believe the data?
Who collected the data?
Where and how were the temperatures taken?
Predicting the Future
Importance of titles and captions
•
Human activities are changing the
environment. Global temperatures have
risen by 0.6 degrees Celsius in the last
200 years.
Does scale make a difference in this
graph?
•
This graph shows carbon dioxide
emissions increasing the last 130 years.
What kind of impact does the image
have on the reader?
Reader Beware!
1.
Graphs have more impact
than the raw data because
they are visual.
2.
Graphs represent
interpretations of data. If
the data has been specially
selected, then the
interpretation is only of the
selected data.
3.
Data can be plotted to create an impression of (or hide) a dramatic trend
when in fact the data does not support such an apparent change.
4.
The creator of the graph can influence the impact of the information and
therefore influence the viewer.
“What is the social cost of “innumeracy” and
illiteracy?
The inability to deal rationally with large numbers,
or with the probabilities [and their graphic
representations] associated with
them, results in misinformed
government policies, confused
personal decisions, and an
increased susceptibility to
pseudo-sciences of all kinds.”
Paulos (1988)
There “are cases where there is no dishonesty
involved, but where people are tricked into false
results by a lack of understanding about what human
beings can do to themselves in the way of being led
astray by subjective efforts, wishful thinking or
threshold interactions.”
Cromer (1993)
Why do we care about visual literacy?
If our students do not understand and get meaning from visual
information, they will be excluded, their point of view not
considered, or they may even manipulated into believing
something not in their best interest.