Fundamentals of crime mapping basic arcview 9.2

2. The data behind the

graphic

3. Right click the
theme to get this
dialog menu.
Click “Open Attribute Table” to
see the data behind the graphic

4. “Options” button
provides another
dialog menu that
lets you work
with table data
Field Names or Columns
Rows or Records
Add a new field,
that can then be
“calculated” or
manually entered
A table can be added to a layout
or exported as DBF

5. Name of New
Field (10
Characters)
Field Type
Options

6. Symbology properties

are different depending
on if you are working
with points, lines, or
polygons.
The easiest is to work

with is Single Symbol
features where
everything in the layer
is displayed using the
same symbol
Can use nominal,

ordinal, ratio or interval
data

7. Some symbol methods may not be useful (pie

charts for example)
Markers


8. Some symbol methods may not be useful (pie

charts for example)
 Lines or Arcs

9. Nominal (categories), Ordinal, Interval and Ratio

(Quantities) can be used with different methods
Fills and outlines

Nominal data
example
Ratio Data
Example

10. Category data

symbology
comes next
It displays data

by unique values
of a field, or
multiple fields
Nominal, ordinal,

ratio or interval
data

11. Next, comes the

quantities
symbology
method
 It uses a number
field in the table
to display data by
classified values
 Ratio and interval
data

12. Six different ways to classify data, with an

added manual method for infinite freedom

13. Equal Interval

Defined Interval

Quantile

Natural Breaks

Geometrical Interval

Standard Deviation


14. Categorical (Qualitative)

Grouping based on some quality
◦
Labels or categories
◦
E.g.; Sex = Male or Female
◦
Nominal or Ordinal
◦
 Nominal the order is not important
 E.g.: Sex = male or female
 Ordinal the order is important
 E.g.; Rank = Officer, Sergeant, Lieutenant, etc
◦ Can be binary or non-binary
 Binary = only two values (male or female)
 Non-Binary = More than two (red, blonde, brunette, etc)

15. Measurement (Quantitative)

◦ Grouping based on some quantity or value
◦ Always numbers
◦ Discrete or continuous
 Discrete = only certain values are possible and data
could have gaps (1, 2, 3, or 4)
 Continuous = Any value along some interval (any value
between 1 and 4 (ie: 3.24211)
◦ Interval or ratio
 In interval data the interval between values is important
(ie; temperature of 30 compared to 110 means
something)
 Ratio data is the best, and the “0” value can be
informative (ie; a grid can have 0 crimes, or any value
up to infinity)

16. http://www.socialresearchmethods.net/kb

/index.php

17. Number of
Equal Interval (ratio, Interval)
 classes desired
◦ The range between the classifications is thedetermines
interval
same
Take the
high value-low
value and for
each of the 5
classes, the value
is 199.61

18. Defined Interval (ratio, interval)

◦ Similar to the equal interval, but here, we
define what the interval will be and thus
establish the classes
In this case the
interval was set
to 150, and so
the number of
classes is
determined by
the interval

19. Quantile (ratio, interval)

◦ A percentage of the values in the class
falling with the range. Each class contains
an equal number of features.
Each of the 10
classes has the
same number of
features within
each class, or
makes up 10% of
the total records

20. Natural Breaks (ratio, interval)

◦ Breaks the data where there are natural
holes between values
Use test exam score example

21. Geometrical Interval (ratio, interval)

◦ This is a classification scheme where the
class breaks are based on class intervals
that have a geometrical series. This
ensures that each class range has
approximately the same number of values
with each class and that the change
between intervals is fairly consistent.
The interval is
determined by a
geometric
equation (large
and small
changes
depending on
breaks in data)

22. Standard Deviation (ratio, interval)

◦ Classes are determined by mean and
standard deviation of values. Can display
by 1, ½, ¼ standard deviations as needed

23. Right click the theme and choose properties,

then choose the Labels tab
You can
combine fields
for labeling
Can label all
features the
same, or use a
query to label
features
differently
Infinite text
choices
Use a field in the
data for the
labels that is
good
Control over placement options, scale
at which labels draw and styles are
available

24. Use to select data by a SQL query

Click this