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pdfSUPPORTING STATEMENT
B.
STATISTICAL METHODS
1.
Universe and Respondent Selection
The Geospatial Capabilities Survey is the first data collection of its kind in fifteen years.
The data collected in this survey will provide the updated data required for the
government to make perceptive investments to meet the needs and enhance the
effectiveness of geospatial capabilities to improve public safety.
The universe is the nation’s law enforcement agencies (LEAs). For this study, we will be
inviting a selection of the law enforcement agencies. We will base the selection on the
1997-1998 survey of police departments sponsored by the NIJ Crime Mapping Research
Center (CMRC). We first updated the classification of the LEAs that were invited to take
the 1997-98 survey by grouping the LEAs into two categories according to the number of
sworn officers (100 or more sworn officers or less than 100 sworn officers). Based on
data from the 2008 Census of State and Local Law Enforcement Agencies (CSLLEA),
the latest agency size statistics available, we identify the current agencies with at least
100 or more sworn offices. Using this updated agency size classification scheme,
agencies that responded to the 1997-98 survey that had at least 100 or more sworn
officers were compared to the 2008 CSLLEA agencies to identify agencies that either did
not respond to the 1997-1998 survey, or that have subsequently become 100 or more
sworn. A breakdown of all respondents to the 1997-98 survey was then conducted. The
results show that there were 217 agencies with at least 100 or more sworn officers that
indicated they had computerized crime mapping as of the 1997-98 survey, 373 agencies
did not, and 19 did not respond to this question. For agencies with less than 100 sworn,
49 had computerized crime mapping at the time of the 1997-98 survey, 1317 did not, and
57 did not respond to the question. These numbers were then used to identify the
sampling frame for the current survey, and to identify the number of agencies to be
selected in each category (please see Table 5 below). It should be noted that the original
sampling frame from 1997-98 is no longer available and as such we reduced the sampling
frame for agencies of 100 or less to those that responded to the original survey1.
1
This
will
limit
the
generalizability
of
the
current
study
in
two
ways.
First
agencies
that
have
recently
formed
will
not
have
been
in
either
sampling
frame.
Second
agencies
that
have
become
100
or
more
sworn
(since
2008)
and
that
did
not
reply
to
the
original
survey
will
also
not
be
in
either
sampling
frame.
The
findings
of
this
survey
will
not
be
applicable
to
these
two
groups.
Table 5: 1997-98 CMRC Survey
199741998-Computerized-Crime-Mapping-Question
Did-not-return1997498-Survey
Yes
No
Missing**
Agency-Size*
Total
100#or#more
217
373
19
465 1074
Cannot#be#
Less#than#100
49
1317
57
1423
determined
Total
266
1690
76
465 2497
*Based#on###sworn#officiers#in#2008#Census#of#State#and#Local#Law#Enforcement#Agencies#(CSLLEA)
**Did#not#answer#computerized#crime#mapping#question#in#1997L98#survey
Based on the sampling frame shown in Table 5, we doubled the probability of selection
for LEAs with 100 or more sworn officers. This action is not based on scientific
deductions, but rather on the fact that past studies have shown lower use of computerized
crime mapping by LEAs with fewer than 100 sworn officers.2 This step results in the
sampling that we will use for the 2014 Geospatial Capabilities Survey. That sampling
frame will include 546 LEAs with 100 or more sworn officers based on 110 that replied
“Yes” in the 1997-98 survey, 190 that replied “No”, 9 that did not answer the crime
mapping question in the 1997-98 survey, and 237 that either did not return the 1997-98
survey or became 100 or larger between the 1997-98 survey and the 2008 CSLLEA. In
addition, the 2014 Geospatial Capabilities Survey sampling frame will include 361 LEAs
with less than 100 sworn officers based on 12 that responded “Yes” to the 1997-98
survey, 335 that responded “No”, and 14 that did not answer the crime mapping question.
The number or agencies to be selected from each category in the sampling frame for the
2014 Geospatial Capabilities Survey is shown in Table 6.
Table 6: 2014 Geospatial Capabilities Sampling Frame
Did'not'return'
Agency'Size*
Yes
No
Missing** 1997998'Survey
100#or#more
110
190
9
237 546
Less#than#100
12
335
14
0 361
Total
122
525
23
237 907
*Based#on###sworn#officiers#in#2008#Census#of#State#and#Local#Law#Enforcement#Agencies#(CSLLEA)
**Did#not#answer#computerized#crime#mapping#question#in#1997K98#survey
2
For
example,
the
1997-‐1998
survey
of
2004
police
departments
sponsored
by
the
NIJ
Crime
Mapping
Research
Center
(CMRC)
found
that
36%
of
the
large
departments
used
computerized
crime
mapping
and
only
3%
of
the
small
departments
used
crime
mapping
(Mamalian
and
LaVigne
1999).
Other
studies,
such
as
Chamard’s
examination
of
the
CMRC
data
shows
that
diffusion
of
crime
mapping
was
much
more
rapid
in
large
department
than
those
with
fewer
than
100
sworn
officers.
Moreover,
data
such
as
that
from
the
Law
Enforcement
Management
and
Administration
statistics
surveys
conducted
from
1997
and
1999
show
that
the
extent
of
discontinuing
the
use
of
crime
mapping
is
much
more
prevalent
in
smaller
departments
(48.3%
discontinuance)
than
in
larger
departments
(2.7%
discontinuance).
2.
Procedures for Collecting Information
Data collection will involve a series of mailings, non-response follow-ups, and retrieval
of inconsistent items. RAND is skilled at using the “classic” non-response conversion
techniques. There is a delicate balance between strongly encouraging non-respondents to
complete a survey and over-pressuring them. RAND staff recognizes that most law
enforcement agencies are supportive of research but are burdened with competing
demands on limited time resources. RAND staff members have a great deal of
experience in tactfully persuading non-respondents to complete surveys and at the same
time recognizing that the Geospatial Capabilities Survey is completely voluntary in
nature. RAND’s approach to data collection and non-response follow-up is based on
previous project experience and recommendations made by Dillman and colleagues
(Dillman, Smyth et al., 2009).
Although Dillman et al. recommend that researchers implement five distinct contacts,
RAND recognizes that surveys may have different requirements. RAND staff will use
five contacts (i.e., pre-notification letter, initial survey mailing, initial thank-you/reminder
letter, second reminder letter survey, and final reminder letter). Since RAND has no
access to e-mail addresses or direct telephone numbers of the heads of law enforcement
agencies, U.S. postal service letters are deemed to be the best method to solicit responses.
NIJ has spoken with representatives of the International Association of Chiefs of Police
(IACP) and the IACP leadership has agreed to support the survey by posting a notice on
its website to encourage participation once the invitations have been mailed.
The Geospatial Capabilities Survey can be completed electronically or by paper. The
pre-notification letter will serve as the letter of invitation. That letter will include a
website address, login, and password information for the invited participant to download
the electronic version of the survey questionnaire.
RAND’s offer of electronic and paper versions of the questionnaire will allow each law
enforcement agency to choose the means most convenient for it to participate in the
survey. Electronic versions can be returned by e-mail and paper versions can be returned
by mail in a pre-addressed postage-paid envelope that will be mailed out with each paper
questionnaire. It is estimated that completion of the geospatial capabilities questionnaire
will take about 50 minutes to complete.
The electronic version of the questionnaire will be in the form of an Excel workbook.
Participants will need access to Microsoft Excel 2007 or more recent for Windows
computers (PC) or Microsoft Excel 2011 for Apple computers (Mac) to use the electronic
version of the survey. Since Excel is included in the Microsoft Office suite commonly in
use throughout government and business enterprises, we believe that most, if not all, of
the nation’s largest law enforcement agencies will have access to Excel. The Excel
workbook with the survey questionnaire will have two worksheets. The first worksheet
will provide written instructions and contact information for further assistance. The
second worksheet will be the electronic form of the questionnaire. The Excel workbook
will be posted on a website. For security purposes, invited participants will receive the
website address, login name, and password on their invitation letters. Once logged in, the
invited participant can download the Excel workbook, request or decline a paper version
of the questionnaire, or decline the invitation to participate. Those invited participants
who do not decline the paper version will receive a paper version by mail regardless if
they have downloaded the Excel version. If an invited law enforcement agency elects to
decline the invitation, that agency will not receive a paper version of the questionnaire. If
a participant declines the invitation to participate, but later decides to participate, that
agency can log in again at the website with the login and password provided in the
invitation letter and download the questionnaire or request a paper copy by mail. The
option to rescind a declination to participate will be available until the last day of the
survey, TBD date here.
Those agencies that have not declined the invitation to participate, but have not submitted
responses by approximately the three-week, five-week, and seven-week marks will
receive thank-you/reminder letters, as appropriate. The agencies that have declined the
invitation will not receive any subsequent mailings after declination unless specifically
requested by the agency.
RAND will rely on experienced reviewers and coders to ensure that hardcopy surveys are
free of errors prior to data entry. If clarifications are required, RAND will follow-up
using the contact information provided on the submission to obtain clarified responses.
The Geospatial Capabilities Survey is completely voluntary. Therefore, some agencies
will elect to not provide responses to some questions. Blank responses will be interpreted
as declinations to provide responses. RAND will not make further contact in attempt to
fill blanks in a submission.
To ensure high-quality data, RAND will employ a standard, integrated set of software
tools that encompass the entire data processing and delivery mechanism, including
receipt control, data entry, data quality review, and data delivery. All hard copy surveys
will be entered directly into a database upon receipt. Electronic surveys are entered by
the respondents and are checked for consistency within the controls built into the Excel
based questionnaire system. The data submitted in an electronic version will be
transferred to the database upon receipt. Both the electronic and paper versions of the
survey will clearly display contact information for assistance in completing the survey.
RAND will also review the frequencies from data entry as well as frequencies from early
electronic survey responses. Any issues noted will be investigated and resolved. The
data will also be subjected to rigorous automated cleaning.
3.
Methods to Maximize Response
RAND staff recognizes the importance of achieving a high response rate to ensure the
usefulness and credibility of the proposed data collection. RAND is highly skilled in
getting practitioners to complete agency surveys. RAND recognizes though that despite
planned efforts to achieve a high response rate (e.g., training the data collection staff and
working with NIJ to secure support of key organizations such as the IACP), it is
reasonable to expect that non-response will occur. To maximize response rates we will
provide both a traditional paper option and an electronic means for the respondents to
complete the survey. Participants can return the paper survey questionnaires by mail in
an enclosed pre-addressed stamped envelope or use the electronic version and return that
be e-mail. Both the paper and electronic versions of the questionnaire have been
designed to facilitate ease of completion. The follow-up plan is based off of best
practices while balancing the need for response and the agency’s right to decline and is
comprised of letters to the head of the law enforcement agency.
RAND will provide NIJ with the website address for the electronic version of the
questionnaire for forwarding to the IACP for posting on the IACP website along with a
message from IACP leadership encouraging its members to participate in the Geospatial
Capabilities Survey.
4.
Testing of Procedures
Multiple rounds of review by RAND and NIJ staff and feedback from BJA, BJS, the
Navy Research Laboratory (NRL), Department of Homeland Security (Science and
Technology Office), and Community Oriented Policing Services (COPS) has attempted
to minimize the complexity and length of the survey in order to lower the burden on
respondents. Only those items of direct relevance and deemed critical by the project team
and NIJ were kept in the survey. The level of effort necessary to complete the survey
was assessed during a pilot test in 2013. Please see Attachment 3 which contains the
Pilot Test Report.
Key elements of the pilot testing and the results are summarized here. A convenience
sample was used for the pilot test based on recommendations from NIJ. Participants
were asked to complete and return the survey questionnaire and complete a pilot test
evaluation that solicited pilot test participant responses on their experience with the
survey questionnaire. Nine law enforcement agencies completed the pilot test and all
selected the electronic format.
Feedback provided by pilot test participants has been incorporated into the survey forms.
Questions that were not easily answered by the pilot test responders were removed from
the survey. Questions reported to be ambiguous were clarified.
5.
Contacts for Data Collection
Person to contact for information on methodology, conducting the survey, and analyzing
the data:
Carolyn Wong, Ph.D.
Senior Operations Researcher
The RAND Corporation
1776 Main Street
Santa Monica, CA 90401
Phone: (310) 393-0411
Joel Hunt
C.
National Institute of Justice (DOJ)
Room 7324
810 Seventh Street NW
Washington, DC 20531
Phone: (202) 616-8111
ATTACHMENTS
Attachment 1: Geospatial Capabilities Survey
Attachment 2: Geospatial Capabilities Electronic Format (Excel) Example
Attachment 3: Pilot Test Report
Attachment 4: Geospatial Capabilities Pre-notification Letter
Attachment 5: Geospatial Capabilities Survey Electronic Format Introduction
Attachment 6: Geospatial Capabilities Thank You Reminder 1
Attachment 7: Geospatial Capabilities Thank You Reminder 2
Attachment 8: Geospatial Capabilities Last Chance Reminder
REFERENCES
Charmard, S., (2006). “The History of Crime Mapping and Its Use by American Police
Departments,” Alaska Justice Forum, Fall 2006, Vol. 23, No. 3.
Dillman, D. A., J. D. Smyth, et al. (2009). Internet, Mail and Mixed-Mode Surveys: The Tailored
Design Method, 3rd edition. Hoboken, NJ, John Wiley.
Mamalian, C. A, N. G. LaVigne, et al (1999). The Use of Computerized Crime Mapping by Law
Enforcement: Survey Results, United States Department of Justice, Office of Justice Programs,
National Institute of Justice, Washington, D. C., FS 000237.
File Type | application/pdf |
File Title | OMB ICR 1121-NEW_Supporting_Statement_B_010614 Rev 3.1 |
Author | Wong, Carolyn |
File Modified | 2014-05-01 |
File Created | 2014-05-01 |