Data Capture Process Stages UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Overview Objective Major Process Stages Factors/Considerations Document Scanning operations Recognizing operations Verifying operations Coding Assistance Factors/Considerations UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008 2

Objective To provide an overview of the major process stages associated with optical data capture and quality assurance considerations UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Major Process Stages Document Scanning Recognizing Verifying Scanner Speeds are dependent on process chosen Recognizing Recognizing is dependent on the sophistication of the recognition engine Automatic Electronic Verification Major Process Stages Verifying Non-Successful Electronic Verification prepare data in a form suitable for entry into computer Coding Assistance UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Document Scanning Stage Key feature: scanning speed Scanning speed will be determined by: Quality of the scanner machines Size of non-drop out color Paper quality, cleanness & weight UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Recognizing Stage Accuracy of interpretation will be determined by: The recognizing process is to interpret images Accuracy of interpretation will be determined by: Recognition engine/memory dictionary; Configuration threshold UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008 6

Verifying Stage Processing can be in geographic order or in random order: Automatic electronic verification Non successful electronic verification: Need to compare the value of the interpreted image with the real image of the form. Image manipulation UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008 7

Verifying Stage (cont.) Image Manipulation: Electronic questionnaires can be sent to specialist operators then back to the original operator if necessary (in some cases, the same questionnaire can be worked on simultaneously by two or more persons) UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Coding Assistance Stage Process in which census questionnaire entries are assigned numerical and/ or alphanumeric values Objective is to prepare data in a form suitable for entry into computer Done by setting up possible responses to each question in the census questionnaire UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Factors to be considered Questionnaire Design & Preparation Data Collection & Processing Considerations Field Operation Staff Training UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Thank You UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Additional material UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Questionnaire Design & Preparation Form Design Advise Consider the number items to be included in a form Pre-print codes near the place where the box for ticks are located Considering the speed of the data capture process - it is advisable to use marks or “ticks” as much as possible Define drop out color properly; use registration marks (allows for quicker recognition) UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Questionnaire Design & Preparation Form Design Advise Maintain consistent pattern in which the information to be collected will be located Do not disturb the visibility of the ticks and marks with titles, labels or instructions Avoid putting "answers" of one field to another page of the questions; Avoid using open ended questions UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008 14

Questionnaire Design & Preparation How to Obtain Good Results of Scanning Select adequate paper quality Select a reliable printing press Use appropriate ink, considering drop out color (for the questionnaires paper heavier than 80 grams per square meter can help avoid paper crashes in scanner) UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008 15

Data Collection & Processing Considerations Field Operation Field Operators should have basic knowledge of the data capture process chosen Staff Training A set-up of required training for staff will ensure quality and effectiveness of the data captured UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Field Operation Considerations Reasons of Error-Reading of OCR: Bad condition of the form because of dirt, folded, crumple, etc Unnecessary lines of characters such as points, decorative strokes, hooks, etc Checking the questionnaires for completeness and consistencies UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Training for Processing Staff Installation and set-up break-down of equipment (e.g. hardware and software) Basic software knowledge Scanner operating procedures Troubleshooting (e.g. solutions to common problems/issues) UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008

Control steps Control steps should be taken if the information image is partial or no information to assure the quality of generated files Value Checking Steps Control for Blank Missing Questionnaire Value Checking Steps: Verify that the information captured is the same with the questionnaire Control for Blank: If the information is blank, what type of control must be taken Missing Questionnaire; Make sure that the entire and all questionnaires are scanned completely, no missing and no duplication as well Therefore control procedures including to produce control tables to compare with manual work UNSD-UNESCAP Regional Workshop on Census Data Processing: Contemporary technologies for data capture, methodology and practice of data editing, documentation and archiving Bangkok, Thailand, 15-19 September 2008