4.3
lanny.wilson
Chapter12.ppt© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
Class Name,
Instructor Name
Date, Semester
Hagan, Research Methods in Criminal Justice and Criminology, 9/e
Chapter 12
Data Management: Coding, Tabulating, and Simple Data Presentation
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Variables List
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A variables list is a list of variables being measured that is keyed to the question number that is designed to measure each variable.
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
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Simple Data Presentation
Ratios
Percentages
Proportions
Rates
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
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The Frequency Distribution
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Frequency Distribution
In addition to the calculation of summary statistics, it is standard procedure for researchers to summarize and group data into a form that is more easily interpreted by the reader.
Graphs or pictorial presentations of data are an attractive means of capturing the reader’s attention as well as of summarizing data, particularly information from frequency distributions.
- Pie charts
- Bar graphs
- Frequency polygons
Software programs such as SPSS aid considerably in the process of selecting and constructing highly useful graphic displays.
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
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Crime clocks are highly inaccurate means of depicting crime change that fails to control for population growth.
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Table-Reading
Tables are presentations of quantitative data in a summary or uniform fashion.
The first step in systematically reading a table
is to carefully read the title. A good title will inform the reader of exactly what is being presented. Table 12.3, for instance, tells us that we are examining personal crimes as opposed to crimes committed against commercial establishments.
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
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Presentation of Complex Data
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One-variable tables are only the first and simplest step in reporting research findings.
It is not unusual to find errors in the presentation of data caused by the improper percentaging of raw information.
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Elaboration
Elaboration refers to the process of introducing or controlling for third variables (control or test factors) by subclassifying original tables.
In discussing the resolution of the causality problem in Chapter 3, we described three steps:
Control for or exclude rival causal factors
Specify the time order (which is X and which is Y)
Demonstrate a relationship between the variables
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Lying with Statistics
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Zeisel (1957) describes how to lie with
statistics.
- Illustrates the misuse of graphic displays that exaggerate or underplay statistical findings by drawing figures out of scale or using calibrations of the horizontal or vertical axes that are misleading
Zeisel, Hans. Say It with Figures. 4th ed. New York: Harper, 1957.
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© 2014 by Pearson Higher Education, Inc Upper Saddle River, New Jersey 07458 • All Rights Reserved
Simple data presentation begins with the re- porting of one-variable frequencies, tallies, or marginals.
Three-variable tables involve the introduction of a third (control) variable to assess its impact (elaborate) on the original relationship.
Elaboration refers to the process of introducing or controlling for third variables by subclassifying tables (creating partial tables).
CHAPTER SUMMARY
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