Aggregate Data

Research Methods

Collecting and Preparing Quantitative Data

Where does a researcher find data for analysis and interpretation?

Existing data collection or archives

Original collection of data and archive for use by other researchers

Aggregate data or individual-level data

Coding Scheme

Monday: “Determine the coding procedure and detailed codebook”

Coding: assigning of numerical values to observations

Preserve level of measurementMutually exclusive & ExhaustiveAllow sensible comparisons for theoryParsimony & DetailAccount for Missing Data

Maintaining a Coding Scheme

Codebook – study and data collection description; location (of data), variable, values, codes (include description, source, survey question, etc. as appropriate)

Codebook created prior to coding and (perhaps) revised as necessary for consistent coding

Verification of coding (intercoder reliability) as well as data entry for coding reliability

Processing error increases for vague instructions, open-ended questions or non-structured material, lack of coder interaction

Coding Devices

Coding Sheets (transfer sheets)Edge codingOptical scanningDirect data entry

1. What is your class standing? a) Freshman b) Sophomore c) Junior d) Senior e) Graduate f) Non-degree g) Other

2. What is your family income level? a) none-$14,999 b) $15,000-34,999 c) $35,000-64,999 d) $65,000-124,999 e) $125,000 or more f) Don’t know

3. How would you describe your party identification? a) Strong Democrat b) Weak Democrat c) Independent, but lean Democrat d) Independent; lean toward neither party e) Independent, but lean Republican f) Weak Republican g) Strong Republican h) Apolitical, I am disinterested in politics

Best Coding/Entry Practices

Data editing and codebook revisionDouble coders a/o Double entry (and

resolution of inconsistencies)Data cleaning

wild or illegitimate codesfilter or contingency questions

Six Stagesof the Research Process

Formulation of TheoryOperationalization of TheorySelection of Appropriate Research

TechniquesObservation of Behavior (Data Collection)Analysis of DataInterpretation of Results

Reporting Results:Writing and Evaluating Reports

TitleAbstractIntroductionMethodsFindingsConclusion

Tips on Style

Work from an outlineBe simple (parsimonious) and preciseUse words and phrases you know Revise, revise, revise (reread, revise, rewrite)Seek others’ opinionsDo not overstate a pointDistinguish observation and opinionUse proper citation & documentation of

sources

Critical Reading: Is there…

Clearly specified research question?Demonstrated value and significance?Clear concepts? Clear explanations?Identified dependent and independent

variables?Hypothesis(ses) empirical, general, &

plausibleValid and reliable measures?Specified unit of analysis and observations?Identified sample selection problems?

Good checklist (pp.384-385)

Aggregate Data

Categories of aggregate indicatorsSummative indicators—Additive group

characteristicsSyntality indictors—Group or system

characteristicsTypes of groups

Geographic groupsDemographic groups

Six Types (and Sources) of Aggregate Data

Census data (US and other)Organizational data (government and private)Sample surveysPublications’ contentEvent dataJudgmental data

Challenges for Data Collection and Manipulation

Variable precisionStandardizationData transformation Index constructionEcological fallacy Reduction or Individualistic Fallacy