16-1 Chapter 16 Data Preparation and Description McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc., All Rights Reserved. 16-2 Learning Objectives Understand . . . • importance of editing the collected raw data to detect errors and omissions • how coding is used to assign number and other symbols to answers and to categorize responses • use of content analysis to interpret and summarize open questions 16-3 Learning Objectives Understand . . . • problems and solutions for “don’t know” responses and handling missing data • options for data entry and manipulation 16-4 Exhibit 16-1 Data Preparation in the Research Process 16-5 Editing Accurate Arranged for simplification Consistent Criteria Complete Uniformly entered 16-6 Field Editing • • • • Field editing review Entry gaps identified Callbacks made Validate results 16-7 Central Editing Be familiar with instructions given to interviewers and coders Do not destroy the original entry Make all editing entries identifiable and in standardized form Initial all answers changed or supplied Place initials and date of editing on each instrument completed 16-8 Exhibit 16-2 Sample Codebook 16-9 Exhibit 16-3 Precoding 16-10 Exhibit 16-3 Coding OpenEnded Questions 16-11 Coding Rules Appropriate to the research problem Exhaustive Categories should be Mutually exclusive Derived from one classification principle 16-12 Content Analysis QSR’s XSight software for content analysis. 16-13 Types of Content Analysis Syntactical Referential Propositional Thematic 16-14 Exhibit 16-4 & 16-5 Open-Question Coding Locus of Responsibility Mentioned Not Mentioned A. Company ________________________ ________________________ B. Customer ________________________ ________________________ C. Joint Company-Customer ________________________ ________________________ F. Other ________________________ ________________________ Locus of Responsibility A. Management 1. Sales manager 2. Sales process 3. Other 4. No action area identified B. Management 1. Training C. Customer 1. Buying processes 2. Other 3. No action area identified D. Environmental conditions E. Technology F. Other Frequency (n = 100) 10 20 7 3 15 12 8 5 20 16-15 Exhbit 16-7 Handling “Don’t Know” Responses Question: Do you have a productive relationship with your present salesperson? No Don’t Know 10% 40% 38% 1 – 3 years 30 30 32 4 years or more 60 30 30 100% n = 650 100% n = 150 100% n = 200 Years of Purchasing Less than 1 year Total Yes 16-16 Data Entry Keyboarding Digital/ Barcodes Database Programs Optical Recognition Voice recognition 16-17 Missing Data Listwise Deletion Pairwise Deletion Replacement 16-18 Key Terms • • • • • • • • • • Bar code Codebook Coding Content analysis Data entry Data field Data file Data preparation Database Don’t know response • Editing • Missing data • Optical character recognition • Optical mark recognition • Precoding • Record • Spreadsheet • Voice recognition 16-19 Appendix 16a Describing Data Statistically McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc., All Rights Reserved. 16-20 Frequencies A Unit Sales Increase (%) 5 6 7 8 9 Total Frequency Percentage 1 2 3 2 1 9 11.1 22.2 33.3 22.2 11.1 100.0 Cumulative Percentage 11.1 33.3 66.7 88.9 100 B Unit Sales Increase (%) Frequency Percentage Cumulative Percentage Origin, foreign (1) 6 7 8 1 2 2 11.1 22.2 22.2 11.1 33.3 55.5 Origin, foreign (2) 5 6 7 9 Total 1 1 1 1 9 11.1 11.1 11.1 11.1 100.0 66.6 77.7 88.8 100.0 16-21 Distributions 16-22 Characteristics of Distributions 16-23 Measures of Central Tendency Mean Median Mode 16-24 Measures of Variability Variance Quartile deviation Standard deviation Dispersion Interquartile range Range 16-25 Summarizing Distributions with Shape 16-26 Symbols Population Sample Mean µ X Proportion p Variance 2 s2 Standard deviation s Size N n Standard error of the mean x _ Sx Standard error of the proportion p Sp _ Variable _ 16-27 Key Terms • • • • • Central tendency Descriptive statistics Deviation scores Frequency distribution Interquartile range (IQR) • Kurtosis • Median • Mode • • • • • Normal distribution Quartile deviation (Q) Skewness Standard deviation Standard normal distribution • Standard score (Z score) • Variability • Variance