Download UNIT E: DATA VISUALIZATION

Scientific and Technical Visualization I
Notes V105.03
Interpreting Data
A. Understand the Cartesian Coordinate System
1. 2D system
a. _____ and ____ coordinates. X is _____________ and y is ____________
b. Identify the number of each quadrant
c. Positive values are ____________and negative values are __________the
center line.
d. Place the correct x any y positive and negative values for each quadrant.
e. Plot the following points in 2D space
-3, 2
4, 5
5, -3
-1, -2
2. The 3D coordinate system
a. X, Y, and ___________ coordinate. Where is the z axis in relationship to the x
and y axis? Draw and explain
b. Where are positive and negative z values?
c. Where is the z-axis origin?
d. Practice plotting these points in 3D space. (1, 2, 3), ( -1,-2,-3), (1, -2, 3),
(-1, 2, -3)
B. Interpret data from charts and graphs
1. What is a direct or positive relationship? Values of related variables move in the
__________ direction. If the points cluster around a line that runs from the lower
left to upper right of the graph area, then the relationship between the two
variables is _____________ or direct. An increase in the value of x is more likely
associated with an _________ in the value of y. The closer the points are to the
line, the stronger the relationship.
2. List 2 other positive relationships?
1.
2.
EXAMPLE:
Income and Consumption
3. What is an Inverse or negative Relationships? Negative Values move in
__________ directions. If the points tend to cluster around a line that runs from
the upper left to lower right of the graph, then the relationship between the two
variables is negative or _____________.
4. Name two other negative relationships.
1.
2.
EXAMPLE
3. Identify trends in data
1. A _____________________________ is a line drawn through a graph of two
variables. The line is chosen so that it comes as close to the points as possible.
This line can show the data trend.
C. Dealing with data
1. ___________ data is categorized into a logical order like 1st, 2nd, and 3rd. A good
example is the Likert scale used on many surveys: 1=Strongly disagree;
2=Disagree; 3=Neutral; 4=Agree; 5=Strongly agree.
2. Name two other examples: 1.
2.
Ordinal data
3.
_________ data are categorical data where the order of the categories is arbitrary.
-Data that is arranged in order, a sequenc e,
A good example is race/ethnicity values: 1=White, 2=Hispanic,
3=American
or a list suc h as the alphabet, or num bers.
Indian, 4=Black, 5=other. (Note that the order of the categories is random.)
4.
Name two other examples: 1.
ABC...
2.
1,2,3,4,5
STUDENT WORK
Ordinal data
-Data that is arranged in order, a sequenc e,
or a list suc h as the alphabet, or num bers.
ABC...
Nominal data
-Data that is not arranged in any particular order
and usually nam es objects.
Dog
Mouse
Cat
1,2,3,4,5
Nominal data
5. ________
quantities -- have magnitude but not a direction and should thus be
-Data that is not arranged in any particular order
and usually from
nam es objects.
distinguished
vectors (i.e. distance, power, speed). Just because you know
Dog
Mouse
Cat
the speed a car is traveling does not mean you know the direction the car is
traveling in.
6. Draw an example of a scalar quanity.
7. _________quantity -- A mathematical concept represented as a line with a
starting point, a length and direction. Vectors can be described with mathematical
equations. Vectors have both magnitude and direction. Most 2D and 3D computer
graphic software packages create shapes using vectors.
8. Draw an example of a vector quantity.
5. ____________ data -- includes information that can be obtained that is not
___________ in nature such as interviews, direct observation, and written
documents like newspapers, magazines, books, and websites.
6. List 2 examples. 1.
2.
7.______________data -- includes information that can be obtained that is numerical
in nature. Examples include the temperature at 12 pm in Charlotte on 4/30/04, the
size of a leaf, and the number of students who passed the VOCATS test.
8. List 2 examples.1.
2.
9. Mean = _________________. To calculate the mean, add all the given numbers,
and then divide by the total count.
10. Find the mean of these numbers: (Add and divide by the number of numbers.)
1, 2, 3, 1, 2, 2, 3
11. _________ = Middle. It is defined as the middle value of several readings, where
all the readings are placed in an increasing or decreasing order. Find the median
of these numbers:
1, 1, 2, 2, 3, 4, 7, 8, 9
12. Mode = _____________. It is defined as the most common value found in a group
consisting of several readings. Find the mode of these numbers:
1, 1, 2, 2, 3, 4, 7, 8, 9
EXAMPLE: A
person wrote down the time he spent on the studying in a
week.
Day
Monday
Study time
60 min.
Tuesday
Wednesday
35 min.
40 min.
Thursday
35 min.
Friday
45 min.
MEAN:
Add all the time together, and then divide by 5.
60+35+40+35+45=215 minutes
215 minutes 5 = 43 minutes per night
MEDIAN:
list all of the values in descending order, and
then look for the value in the middle.
60, 45, 40, 35, 35  40 is the median
MODE:
look for the number that occurs the most.
35 occurs 2 times, all of the other numbers only
once
35 is the mode
10. Independent variable -- is the variable that you believe might influence your
outcome measure. It is the variable that you ____________ It also might represent
a demographic factor like age or gender. It is graphed on the _________
11. _______________ variable -- is the variable that is influenced or modified by
some treatment or exposure (the independent variable). It may also represent the
variable you are trying to predict or the variable that you measure. It is graphed on
the ________________
12. ________________________ -- in an experimental design refers to keeping
outside influences the same for all groups. The goal in experimental design is to
group units in such a way that most unwanted experimental errors would be
removed. A controlled experiment usually results in the most powerful
comparisons and the clearest conclusions.
EXAMPLES:
EXPERIMENT
DEPENDENT
VARIABLE
INDEPENDENT
VARIABLE
POSSIBLE
CONTROL
How do plants
respond to different
colors of light?
Plant growth
(response)
Different colors of light
Same number of
plants in each group
How do different
amounts of salt affect
the boiling point of
water?
Boiling point of water
Amounts of salt
Same amount of water
each time
How does tire
pressure affect gas
mileage?
Gas mileage
Tire pressure
Same grade of gas for
each trial
13. Fill in the chart below for variables.
EXPERIMENT
DEPENDENT
VARIABLE
INDEPENDENT
VARIABLE
POSSIBLE
CONTROL
How do amoebas
respond to different
colors of light?
How do different
amounts of
phosphates affect
oxygen levels in
water?
Does our sense of
smell and sight affect
how food tastes?
14. Empirically derived and computationally derived data
Empirically Derived
Data
Data you can physic ally
measure like length, width, or
height that does not require a
mathematic al formula to find.
Computationally
Derived Data
-Data that requires you to use
a formula and perform a
calculation to get a
measurement such as area,
volume, or c irc umferenc e.
5c m x 9c m = 45c m squared
Wid th = 9 c m
15. List 2 examples of empirically derived data.
1.
2.
16. 15. List 2 examples of computationally derived data.
1.
2.
Length = 5 c m