King Fahd University of Petroleum & MineralsDepartment of Management and Marketing

MKT 345 Marketing ResearchDr. Alhassan G. Abdul-Muhmin

Editing and Coding Reference: Zikmund, Chapter 19

Learning ObjectivesAt the end of this discussion you should be able to:Explain the concepts of editing and coding List the important considerations in editing and codingList and explain the key issues in error-checking and data transformationExplain the contents and uses of a code bookEdit and code completed questionnaires

Overview of the Stages of Data Analysis

EDITINGThe process of checking and adjusting responses in the completed questionnaires for omissions, legibility, and consistency and readying them for coding and storage

Types of Editing1. Field Editing 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.2. In-house EditingEditing performed by a central office staff; often dome more rigorously than field editing

Purpose of EditingFor consistency between and among responsesFor completeness in responses to reduce effects of item non-responseTo better utilize questions answered out of orderTo facilitate the coding process

Editing for CompletenessItem NonresponseThe technical term for an unanswered question on an otherwise complete questionnaire resulting in missing data.Plug ValueAn 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.ImputeTo fill in a missing data point through the use of a statistical algorithm that provides a best guess for the missing response based on available information.

Facilitating the Coding ProcessData Clean-upChecking written responses for any stray marksEditing And Tabulating Dont Know AnswersLegitimate dont know (no opinion)Reluctant dont know (refusal to answer)Confused dont know (does not understand)

Editing (contd)Pitfalls of EditingAllowing subjectivity to enter into the editing process. Data editors should be intelligent, experienced, and objective.Failing to have a systematic procedure for assessing the questionnaires developed by the research analystAn editor should have clearly defined decision rules to follow. Pretesting EditEditing during the pretest stage can prove very valuable for improving questionnaire format, identifying poor instructions or inappropriate question wording.

CODINGThe process of identifying and classifying each answer with a numerical score or other character symbol The numerical score or symbol is called a code, and serves as a rule for interpreting, classifying, and recording dataIdentifying responses with codes is necessary if data is to be processed by computer

Coding - ContinuedCoded data is often stored electronically in the form of a data matrix - a rectangular arrangement of the data into rows (representing cases) and columns (representing variables) The data matrix is organized into fields, records, and files:Field: A collection of characters that represents a single type of dataRecord: A collection of related fields, i.e., fields related to the same case (or respondent)File: A collection of related records, i.e. records related to the same sample

Key Issues in CodingPre-Coding Fixed-Alternative Questions (FAQs) -Writing codes for FAQs on the questionnaire before the data collectionCoding Open-Ended Questions - A 3-stage process:(a) Perform a test tabulation, (b) Devise a coding scheme, (c) Code all responsesTwo Rules For Code Construction are:Coding categories should be exhaustiveCoding categories should be mutually exclusive and independent

Issues in Coding - ContinuedMaintaining a Code Book - A book that identifies each variable in a study, the variables description, code name, and position in the data matrixProduction Coding - The physical activity of transferring the data from the questionnaire or data collection form [to the computer] after the data has been collected. Sometimes done through a coding sheet ruled paper drawn to mimic the data matrixCombining Editing and Coding

AFTER CODING .. Data Entry - The transfer of codes from questionnaires (or coding sheets) to a computer. Often accomplished in one of three ways:On-line direct data entry e.g. as for CATI systemsOptical scanning for highly structured questionnairesKeyboarding data entry via a computer keyboard; often requires verification

After Coding - ContinuedError Checking Verifying the accuracy of data entry and checking for some kinds of obvious errors made during the data entry. Often accomplished through frequency analysis.

After Coding - ContinuedData Transformation Converting some of the data from the format in which they were entered to a format most suitable for particular statistical analysis.Often accomplished through re-coding, to:reverse-score negative (or positive) statements into positive (or negative) statements; collapse the number of categories of a variable