Data Preparation for Analysis Chapter 11

Editing “The inspection and correction of the data received from each element of the sample.” “The inspection and correction of the data received from each element of the sample.”

Editing Incomplete Answers Incomplete Answers What to do? What to do? General rule General rule Wrong Answers Wrong Answers Dog food example Dog food example Bookstore example Bookstore example Answers that Reflect Lack of Interest Answers that Reflect Lack of Interest Examples Examples

Coding “Transforming raw data into symbols” “Transforming raw data into symbols” Closed-ended items Closed-ended items Genders Genders Scales Scales

Coding Open-ended items Open-ended items Factual Factual Examples Examples Exploratory open-ended Exploratory open-ended Use more than one coder Use more than one coder Go through questionnaire and highlight responses Go through questionnaire and highlight responses Specify the categories in which responses are to be placed Specify the categories in which responses are to be placed Code responses into categories Code responses into categories Compare results between coders Compare results between coders

Coding Building the data file Building the data file The Codebook The Codebook Variable name Variable name How coded How coded How to treat missing data How to treat missing data

Cleaning the Data Blunders Blunders An error that arises during editing, coding, or data entry An error that arises during editing, coding, or data entry How to find How to find Checking Checking Double-entry Double-entry Optical scanning Optical scanning

Handling Missing Data Item Nonresponse Item Nonresponse What to do? What to do? Eliminate entire case Eliminate entire case Eliminate case from analysis with that variable Eliminate case from analysis with that variable Substitute missing values Substitute missing values Contact the respondent Contact the respondent