Ensuring the quality of data

The procedure for entering and managing data, whether collected electronically or on paper, should include guidance on:

  • key staff and supervisors responsible for each stage (database design, data entry, cleaning, management, processing and analysis);
  • the process for entering data;
  • software and equipment to be used;
  • developing the data entry screen with appropriate validation checks and skips;
  • the flow and tracking of data from the field to the final format; and
  • data confidentiality and security.

The choice of paper-based or electronic data collection must be made early on in the survey planning process. Electronic data collection is the preferred method, as it reduces time and improves data quality. In addition, electronic data can be backed up every day while teams are still in the field, whereas paper forms risk being lost or misplaced before the data are entered into an electronic database. Further discussion of the advantages and disadvantages of each method can be found in Module 4: Survey design. When paper-based questionnaires are used, sufficient entry staff are needed to perform double data entry (entry of each questionnaire by two independent staff).

Each survey team member, from the interviewers to the Survey coordinator should have a clear task related to data quality in his or her roles and responsibilities. During field work, the responsibility for data integrity and quality starts with the interviewers. Information should be entered in a standardized, legible format onto paper questionnaires and other data collection forms. Ultimately, team leaders are responsible for the consistency and completeness of the team’s data. Team leaders in the field need to review all data on the questionnaires to ensure that they are clear and complete, and check for potential data errors or mismatching between specimens and individual or household questionnaires. See Module 11: Data collection tools, field manual, and database, Module 13, Field logistics for more information on these checks.