Fieldwork and Sampling

A new collection of rules and procedures for WVS-7 has been elaborated by the Scientific Advisory Committee of the WVSA and can be provided by the WVSA Scerteariat upon the request (for WVS survey teams only). The document comprises requirements towards sampling procedures, sample size, time of survey implementation, questionnaire localization, data submission to the WVS and etc. Excerpts from the collection of rules for WVS-7 are presented below.

Survey Questionnaire

WVS requires implementation of the common questionnaire fully and faithfully, in all countries included into one wave. Any alteration to the original questionnaire has to be approved by the EC. Omission of no more than a maximum of 12 questions in any given country can be allowed.

WVS-7 questionnaire will be availabe in English, Spanish, Arabic and Russian. All the other translations have to be conducted by the national teams. In any given country, the questionnaire must be translated into all languages which serve as the first language for 15 % (or more) of the population.

Sampling

The minimum sample size - i.e. the number of completed interviews which are included into the national data-set in the most of countries is 1200. Samples must be representative of all people in the age 18 and older residing within private households in each country, regardless of their nationality, citizenship or language. Whether the sampling method is full probability or a combination of probability and stratified, the national team should aim at obtaining as many Primary Sampling Units (starting points in case of random route sampling) in the sample as possible. It is highly recommended that a number of respondents per a PSU (or a route in case of random route sample) is not exceeding 10 respondents. It is possible to have several Primary Sampling Units per one settlement; they should be located in quite a good distance from each other. WVSA requires a complete explanation of proposed sampling procedures before the beginning of the survey fieldwork.

Survey method

The main method of data collection in the WVS survey is face-to-face interview at respondent’s home / place of residence. Respondent’s answers could be recorded in a paper questionnaire (traditional way) or by CAPI (Computer Assisted Personal Interview). The approval of the Scientific Advisory Committee in writing is necessary for application of any methods of data collection other than face-to-face interview.

Data collection (Field work)

Following the sampling, each country is left with a representative national sample of its public. These persons are then interviewed during a limited time frame decided by the Executive Committee of the World Values Survey using the uniformly structured questionnaires. The survey is carried out by professional organizations using face-to-face interviews or phone interviews for remote areas. Each country has a Principal Investigator (social scientists working in academic institutions) who is responsible for conducting the survey in accordance with the fixed rules and procedures. During the field work, the agency has to report in writing according to a specific check-list. Internal consistency checks are made between the sampling design and the outcome and rigorous data cleaning procedures are followed at the WVS data archive. No country is included in a wave before full documentation has been delivered. This means a data set with the completed methodological questionnaire and a report of country-specific information (for example important political events during the fieldwork, problems particular to the country). Once all the surveys are completed, the Principal Investigator has access to all surveys and data.

Non response

Non-response is an issue of increasing concern in sample surveys. Investigators are expected to make every reasonable effort to minimize non-response. More specifically,

  • In countries using a full probability design, no replacements are allowed. PIs should plan on as many call-backs as the funding will allow.
  • In countries using some form of quota sampling, every effort should be made to interview the first contact.
  • In any case, and as indicated below, a full report on non-responses is required.

Coverage

WVS surveys are required to cover all residents (not only citizens) between the ages of 18 and 85, inclusive. PI’s can lower the minimum age limit as long as the minimum required sample size for the 18+ population (N=1200) is achieved. WVS requires a complete explanation of proposed sampling procedures before the start of the fieldwork. The sampling plan must be approved by the EC in writing.

Anonymity

All deposited data has been made anonymous at the PI side and the archive deposited files have no means to trace the respondents.