Transcript BRM 8e
Editing and Coding: Transforming Raw Data into Information (Source: W.G Zikmund, B.J Babin, J.C Carr and M. Griffin, Business Research Methods, 8th Edition, U.S, South-Western Cengage Learning, 2008) 1 Objectives 1. Know when a response is really an error and should be edited 2. Appreciate coding of pure qualitative research 3. Understand the way data are represented in a data file 4. Understand the coding of structured responses including a dummy variable approach 5. Appreciate the ways that technological advances have simplified the coding process 2 Stages of Data Analysis Raw Data Nonrespondent Error The unedited responses from a respondent exactly as indicated by that respondent. Error that the respondent is not responsible for creating, such as when the interviewer marks a response incorrectly. Data Integrity The notion that the data file actually contains the information that the researcher is trying to obtain to adequately address research questions. 3 Editing Editing Field Editing The process of checking the completeness, consistency, and legibility of data and making the data ready for coding and transfer to storage. Preliminary editing by a field supervisor on the same day as the interview to catch technical omissions, check legibility of handwriting, and clarify responses that are logically or conceptually inconsistent. In-House Editing A rigorous editing job performed by a centralized office staff. 4 Editing Checking for Consistency Respondents match defined population Check for consistency within the data collection framework Taking Action When Response is Obviously in Error Change/correct responses only when there are multiple pieces of evidence for doing so. Editing Technology Computer routines can check for consistency automatically. 5 Editing for Completeness Item Nonresponse The technical term for an unanswered question on an otherwise complete questionnaire resulting in missing data. Plug Value An answer that an editor “plugs in” to replace blanks or missing values so as to permit data analysis. Choice of value is based on a predetermined decision rule. Impute To fill in a missing data point through the use of a statistical process providing an educated guess for the missing response based on available information. 6 Editing for Completeness (cont’d) What about missing data? List-wise deletion The entire record for a respondent that has left a response missing is excluded from use in statistical analysis. Pair-wise deletion Only the actual variables for a respondent that do not contain information are eliminated from use in statistical analysis. 7 Facilitating the Coding Process Editing And Tabulating “Don’t Know” Answers Legitimate don’t know (no opinion) Reluctant don’t know (refusal to answer) Confused don’t know (does not understand) 8 Coding Qualitative Responses Coding The process of assigning a numerical score or other character symbol to previously edited data. Codes Rules for interpreting, classifying, and recording data in the coding process. The actual numerical or other character symbols assigned to raw data. Dummy Coding Numeric “1” or “0” coding where each number represents an alternate response such as “female” or “male.” 9 Coding Qualitative Data with Words 10 Data Storage Terminology in SPSS 11 A Data File Stored in SPSS 12 Computerized Survey Data Processing Data Entry The activity of transferring data from a research project to computers. Optical Scanning System A data processing input device that reads material directly from mark-sensed questionnaires. 13 Data View in SPSS Serves Much the Same Purpose of a Coding Sheet 14