Coding PracticesCoding Practices

February 4, 2011February 4, 2011

ObjectivesObjectives

By the end of this meeting, participants By the end of this meeting, participants should be able to:should be able to:

a)a) Define a coding scheme for an open Define a coding scheme for an open or closed-ended question.or closed-ended question.

b)b) Explain the logic of recoding survey Explain the logic of recoding survey data.data.

Closed-Ended QuestionsClosed-Ended Questions

a)a) Coding scheme needs to be:Coding scheme needs to be:• Mutually exclusiveMutually exclusive• ExhaustiveExhaustive

a)a) CandidatesCandidates

b)b) IssuesIssues

• Recorded preciselyRecorded precisely

Open-Ended QuestionsOpen-Ended Questions

a)a) Generally harder to code, two Generally harder to code, two general waysgeneral ways

• ManifestManifesta)a) Theoretical/a priori methodTheoretical/a priori method

b)b) Context methodContext method

c)c) MixtureMixture

• LatentLatent

b)b) Responses need to be recorded Responses need to be recorded preciselyprecisely

Creating a codebookCreating a codebook

a)a) Needs to be clear and specificNeeds to be clear and specific

b)b) Frequently coding will change over Frequently coding will change over the course of a project, need to the course of a project, need to record updatesrecord updates

c)c) If changes are made in coding, the If changes are made in coding, the data must stay specificdata must stay specific

Codebook ExampleCodebook Example

StateState

1-Alaska1-Alaska

2-Alabama2-Alabama

3-Arkansas3-Arkansas

4-Arizona4-Arizona

5-California5-California

6-Colorado6-Colorado

7-Conneticut7-Conneticut

8-Delaware8-Delaware

9-Florida9-Florida10-Georgia10-Georgia11-Hawaii11-Hawaii12-Iowa12-Iowa13-Idaho13-Idaho14-Illinios14-Illinios15-Indiana15-Indiana16-Kansas16-Kansas17-Kentucky17-Kentucky

Codebook ExampleCodebook Example

PartyParty

2=Republican2=Republican

1=Democrat1=Democrat

Codebook ExampleCodebook Example

TermsTerms

The number of times the incumbent has The number of times the incumbent has been elected, t/f special election been elected, t/f special election count as a whole termcount as a whole term

Codebook ExampleCodebook Example

MoneyMoney (in thousands) (in thousands)

Money is the amount of total receipts in thousands Money is the amount of total receipts in thousands as reported by the FEC website. Numbers were as reported by the FEC website. Numbers were rounded up or down to the nearest thousand. rounded up or down to the nearest thousand.

ChallengersChallengers

The total number of challengers reconciled The total number of challengers reconciled between the National Journalbetween the National Journal’’s Almanac of s Almanac of American Politics and the FEC website. When American Politics and the FEC website. When discrepancies arose, the Almanac was given discrepancies arose, the Almanac was given primacy. primacy.

Methods of CodingMethods of Coding

a)a) Coding sheetsCoding sheets

b)b) Direct data entryDirect data entry

Coding PracticesCoding Practices

a)a) Errors are important to avoid in Errors are important to avoid in coding data because they can coding data because they can change the resultschange the results

b)b) Some errors are largely impossible to Some errors are largely impossible to correct but there are some methods correct but there are some methods to avoid errorsto avoid errors

• Wild code checkingWild code checking• Consistency checkingConsistency checking

Coding and Recoding Coding and Recoding PracticePractice

a)a) Most of the time we will not be creating our own surveys but Most of the time we will not be creating our own surveys but changing existing ones.changing existing ones.

b)b) R can accommodate us in this process. (logical statements)R can accommodate us in this process. (logical statements)c)c) Examples: Examples:

• Missing data codesMissing data codes• Smaller number of categoriesSmaller number of categories

• Ordered (positive v. neutral v. negative)Ordered (positive v. neutral v. negative)• Binary (positive v. negative)Binary (positive v. negative)

• Create a Scale (I.e., how knowledgable?)Create a Scale (I.e., how knowledgable?)

d)d) Recommendations:Recommendations:• Save R input code. (Why reinvent the wheel?)Save R input code. (Why reinvent the wheel?)• Tabulate new variables and old variables.Tabulate new variables and old variables.

For Next TimeFor Next Time

a)a) Read WKB chapter 7Read WKB chapter 7

b)b) Answer questions 1-3 on pp.169-170Answer questions 1-3 on pp.169-170