Ch05 Concepts, Operationalization, and Measurement

3,515 views
3,245 views

Published on

Maxfield, Michael G. & Babbie, Earl R. (2011). Research Methods for Criminal Justice and Criminology, 6th Edition. Belmont, CA: Wadsworth Publishing

Published in: Technology, Business
0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
3,515
On SlideShare
0
From Embeds
0
Number of Embeds
12
Actions
Shares
0
Downloads
0
Comments
0
Likes
4
Embeds 0
No embeds

No notes for slide

Ch05 Concepts, Operationalization, and Measurement

  1. 1. 1Concepts, Operationalization,and Measurement
  2. 2. OUTLINE Introduction Conceptions and Concepts Operationalization Choices Criteria for Measurement Quality Composite Measures
  3. 3. 3•Because measurement is difficult andimprecise, researchers try to describe themeasurement process explicitly•We want to move from vague ideas of whatwe want to study to actually being able torecognize and measure it in the real world•Otherwise, we will be unable to communicatethe relevance of our idea and findings to anaudience
  4. 4. 4•Clarifying abstract mental images is anessential first step in measurement•“Crime”•Conception – Mental image we have aboutsomething•Concepts – Words, phrases, or symbols inlanguage that are used to represent thesemental images in communication •e.g., gender, punishment, chivalry, delinquency, poverty, intelligence, racism, sexism, assault, deviance, income
  5. 5. 5•Direct observables – Those things or qualitieswe can observe directly (color, shape)•Indirect observables – Require relativelymore subtle, complex, or indirect observationsfor things that cannot be observed directly(reports, court transcripts, criminal historyrecords)•Constructs – Theoretical creations; cannot beobserved directly or indirectly; similar toConcept
  6. 6. 6•Specifying precisely what we mean when weuse particular terms•Results in a set of indicators of what we havein mind•Indicates a presence or absence of theconcept we are studying•Violent crime = offender uses force (orthreatens to use force) against a victim
  7. 7. 7•Dimension – Specifiable aspect of a concept•“Crime Seriousness” – Can be subdivided intodimensions •e.g., Dimension – Victim harm •Indicators – Physical injury, economic loss, psychological consequences•Specification leads to deeper understanding
  8. 8. 8•Concepts are abstract and only mentalcreations•The terms we use to describe them do nothave real and concrete meanings •What is poverty? delinquency? strain?•Reification – Process of regarding as realthings that are not
  9. 9. 9•Conceptual definition (what is SES?) •Working definition specifically assigned to a term, provides focus to our observations •Gives us a specific working definition so that readers will understand the concept•Operational definition (how will we measureSES?) •Spells out precisely how the concept will be measured
  10. 10. 10 Conceptualization Conceptual Definition Operational DefinitionMeasurements in the Real World
  11. 11. 11•Operationalization – The process ofdeveloping operational definitions•Moves us closer to measurement•Requires us to determine what might work asa data-collection method
  12. 12. 12•Measurement – Assigning numbers or labelsto units of analysis in order to represent theconceptual properties•Make observations, and assign scores tothem•Difficult in CJ research because basicconcepts are not perfectly definable
  13. 13. 13•Every variable should have two importantqualities: •Exhaustive – You should be able to classify every observation in terms of one of the attributes composing the variable •Mutually exclusive – You must be able to classify every observation in terms of one and only one attribute•Example: Employment status
  14. 14. 14•Nominal – Offer names or labels forcharacteristics (race, gender, state ofresidence)•Ordinal – Attributes can be logically rank-ordered(education, opinions, occupational status)•Interval – Meaningful distance betweenattributes (temperature, IQ)•Ratio – Has a true zero point(age, # of priors, sentence length, income)
  15. 15. 15•Certain analytic techniques have Levels ofMeasurement requirements•Ratio level can also be treated as Nominal,Ordinal, or Interval•You cannot convert a lower Level ofMeasurement to a higher one•Therefore, seek the highest Level ofMeasurement possible
  16. 16. 16•The key standards for measurement qualityare reliability and validity•Measurements can be made with varyingdegrees of precision•Common sense dictates that the moreprecise, the better•However, you do not necessarily needcomplete precision
  17. 17. 17•Whether a particular measurement technique,repeatedly applied to the same object, wouldyield the same result each time•Problem – Even if the same result isretrieved, it may be incorrect every time•Reliability does not insure accuracy•Observer’s subjectivity might come into play
  18. 18. 18•Test-retest method – Make the samemeasurement more than once – should expectsame response both times•Interrater reliability – Comparemeasurements from different raters; verifyinitial measurements•Split-half method – Make more than onemeasure of any concept; see if each measuresthe concept differently
  19. 19. 19•The extent to which an empirical measureadequately reflects the meaning of the conceptunder consideration•Are you really measuring what you say youare measuring?•Demonstrating validity is more difficult thandemonstrating reliability
  20. 20. 20•Face validity – On its face, does it seem valid?Does it jibe with our common agreements andmental images?•Criterion-related validity – Compares a measureto some external criterion•Construct validity – Whether your variablesrelated to each other in the logically expecteddirection•Content validity – Does the measure cover therange of meanings included in the concept?•Multiple Measures – Alternative measures
  21. 21. 21•Allows us to combine individual measures toproduce more valid and reliable indicators•Reasons for using Composite Measures: •The researcher is often unable to develop single indicators of complex concepts •We may wish to use a rather refined ordinal measure of a variable, arranging cases in several ordinal categories from very low to very high on a variable such as degree of parental supervision •Indexes and scales are efficient devices for data analysis
  22. 22. 22•“Taxonomy”•Produced by the intersection of two or morevariables to create a set of categories or types•e.g., Typology of Delinquent/Criminal Acts(Time 1 and 2) •None, Minor (theft of items worth less than $5, vandalism, fare evasion), Moderate (theft over $5, gang fighting, carrying weapons), Serious (car theft, breaking and entering, forced sex, selling drugs •Nondelinquent, Starter, Desistor, Stable, Deescalator, Escalator
  23. 23. 23•What is disorder? (Skogan, 1990)•Distinguish between physical presence &social perception• Physical disorder: Abandoned buildings,garbage and litter, graffiti, junk in vacant lots•Social disorder: Groups of loiterers, drug useand sales, vandalism, gang activity, publicdrinking, street harassment•Index created by averaging scores for eachmeasure
  24. 24. 24•A composite index is a more valid measurethan a single question•Computing and averaging across all items in acategory create more variation than we couldobtain in any single item•Two indexes are more parsimonious than nineindividual variables•Data analysis and interpretation can be moreefficient

×