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Acquisition Policy


This document articulates the Acquisition Policy of the Roper Center for Public Opinion Research at Cornell University within the context of the Center’s mission. The Acquisition Policy is designed to provide general guidance to the staff as they review potential acquisitions. The policy should be viewed not as a static document but one that must be reevaluated against current survey research methodologies, changing technology, and the Center’s overarching mission.

Mission and Purpose

The overall direction and goals of the acquisition program are governed by the Roper Center for Public Opinion Research mission, which is “to facilitate research on public opinion by faculty, staff, and students at many universities, researchers in the public and private sectors, journalists, policymakers, and private citizens.” A major goal of this mission is to acquire, maintain and make accessible to users the largest collection of polling and survey interview data of broad social, political, economic and cultural significance, potential historic or methodological interest.

Institutional Clientele

The Center provides a wide variety of information, tools and services to its public, commercial and academic users. User sophistication in the analysis and interpretation of survey results varies widely among these core constituents. To fulfill its mission the Center provides introductory, aggregated data for student and general public use while providing more sophisticated information and tools to academic researchers and survey research professionals. Journalists and public policy analysts may make use of both types of material.

The diversity of Center users and uses directly affects the desired type (interpretive reports, marginal data), format (aggregate data, respondent-level data), and currency (new data for existing collections, older data collections not yet acquired) of Center acquisitions.

Acquisition Categories

Two broad categories are included in the scope of the Center’s acquisition efforts.

  1. A primary effort is made to acquire respondent-level data from surveys that may or may not have been released publicly by the original data producer or sponsoring organization. This constitutes the Roper Center’s core collection. Studies in this category offer un-rivaled potential for secondary analysis. The Center was founded, principally, on the acquisition and re-analysis of survey data in this format.
  2. A second category includes interpretive survey reports, marginal data and news releases. These collections supplement the respondent-level data referred to above, and in some cases, provide the only preserved record of the survey. These materials are entered into the online polling database for those surveys based on national samples of the United States adult population, regardless of whether respondent level data is acquired.

While the Center was built upon the acquisition of respondent-level data, the importance of acquiring, preserving and making accessible marginal data cannot be underestimated within the context of the Center’s mission and the diversity of its clientele. Moreover, full marginal data constitute essential documentation of the respondent-level data.

Acquisition Criteria

In addition to the type and format of material, potential acquisitions must be measured against a set of broad criteria. Factors to be considered include:

Basic Data Source and Methodology

Survey and poll data must be derived from interviews as the primary source. Interview data cannot be from exclusively self-selected respondents. In addition, sample populations will act as a guide for both acquisition and processing efforts. Material is generally selected in the following descending order of priority:

  • United States national population probability samples
  • Representative subsamples of US national populations (e.g., women, teenagers)
  • US state exit polls or other state representative polls not in ‘national’ collections
  • Representative samples of other countries and regions

Subject Matter

Collections must be of current value or potential historical interest.

Disclosure of Methodology

Polling methodology must meet the basic disclosure criteria as stated in the American Association for Public Opinion Research Code for Professional Ethics and Practices including:

  1. Information about who sponsored the survey, and who conducted it.
  2. The exact wording of questions asked, including the text of any preceding instruction or explanation to the interviewer or respondents that might reasonably be expected to affect the response.
  3. A definition of the population under study, and a description of the sampling criteria used to identify this population.
  4. A description of the sample selection procedure that gives a clear indication of whether or not the researcher selected the respondents or they were self-selected.
  5. The size of samples and, if applicable, completion rates and information on eligibility criteria and screening procedures. For the purpose of this policy statement response rate definition and calculation will be informed by the AAPOR report entitled “Standard Definitions.” The report defines standardized measures for response rates, cooperation rates, refusal rates and contact rates. Each of these rates requires a count of the disposition of all units selected in the sample. The various disposition codes are standardized in the report.
  6. There should be a discussion of the precision of the findings, including, if appropriate, estimates of sampling error, and a description of any weighting or estimating procedures that were used.
  7. A listing of which results are based on parts of the sample, rather than on the total sample.
  8. The method, location, and dates of data collection.

The Use of Innovative Methodology

Surveys that employ innovative or experimental research methodologies could be of interest to researchers within the field. Indeed, today’s conventional telephone polling was once considered both innovative and controversial, as was computer-assisted personal interviewing a few years later. Judgments must be made regarding the comparability of new types of surveys with those employing more traditional and accepted methodologies. The Center must segregate and preserve studies employing methodologies that have not yet proved themselves until the Acquisitions, Standards and Processing Committee can evaluate the research methods in question and make recommendations.

Risk of Data Loss

Material may be acquired to mitigate the risk of data loss.

Availability of Data Elsewhere

Data may be acquired because the information is not available from another reputable, accessible data archive.

Technical Criteria that may Affect Acquiring Material Include:

  • The general condition of the study/collection and whether it requires costly methods to preserve or make it accessible
  • Whether there are any specific restrictions that would not allow the material to be freely accessible to researchers (however, the Center will occasionally accept “embargoes” on certain questions for limited periods of time, and it will accept a restriction that, for a limited period of time, where data may be disseminated only with the academic membership of the Center)
  • Whether the cost of processing materials is higher than normally expected

What Will Not Be Acquired

There are no firm rules concerning the kinds of survey material that will not be acquired. However, the following list represents a compilation of current practices at the Center and may serve as a guide to the staff and to the Committee as it implements this Acquisition Policy. There have been and will again be exceptions to some or all of these customary practices.

  • Surveys without content that is salient to the Center’s Mission and Purpose, such as many marketing studies of single products
  • Surveys with sample sizes that are too small to represent any population
  • Surveys in which the respondents are entirely self-selected
  • Surveys where release of the respondent-level data would pose an unreasonable and uncontrollable risk of violation of respondents’ privacy and confidentiality
  • Data resulting from “push polls” and other uses of survey methodologies to gather data for purposes other than legitimate survey research
  • Surveys for which the data collector will not provide the full questionnaire

Roles and Responsibilities

The Acquisition Policy recognizes that professional judgment is central to making decisions about new acquisitions. The broad criteria described above will serve as a guide for archive staff in their continuing efforts to build unique and valuable data collections. The Center’s Executive Director will provide final approval of all new acquisition efforts to oversee appropriate interpretation of these guidelines and safeguard against over committing Center resources. Beyond this document, the Acquisitions Committee will serve in an advisory capacity to Center staff. To facilitate this role, archive staff will provide a periodic report on recent acquisitions and rejections. In specific cases where there are questions regarding the implementation of this Policy, Center staff will call upon the Acquisitions Committee for its advice and recommendations.


Given the rapid evolution of technology and its implications for survey research methodologies, the Acquisitions Committee and Center staff will review this Policy annually to ensure that it continues to serve the Center’s needs.


Approved by the Roper Center for Public Opinion Research Board of Directors November 19, 2002
Reviewed in June, 2012