magnifying glass on a desk of scattered letters.

Data Tools and Methodology

Data series

The collection of data characteristics of the target population repeated over time.


Reference information about a data series, responding unit, or single observation. Dimensions are characteristics used to group data into distinct groups such as race, gender, or fields of study.


A summary (mean, mode, total, index, etc.) of variable values for the responding units, such as the total number of doctorate recipients, median salary, and average annual R&D expenditures. In a dataset, the instance of a measure is often referred to as an observation.

Statistical significance

Attained when statistical procedure applied to a set of observations yields a p value that exceeds the agreed level of probability which determines the null hypothesis will be rejected.

Statistical survey

A data collection whose purposes include the description, estimation, or analysis of the characteristics of groups, organizations, segments, activities, or geographic areas. This type of survey may be a census or may collect information from a sample of the target population. Examples of population characteristics that may be explored in NCSES surveys are people, universities, or government entities.


The subject or area of analytical interest for users exploring data or conducting research. Example topics may include fields of study, research and development activity, or college or university enrollment.

Unweighted count

The actual number of responding units found in a particular dataset, table, or measure before any necessary weighting has been applied to the table.


A characteristic of an object of study in a dataset that may take on more than one of a set of values to which a numerical or categorical measure can be assigned. Examples of common variables include occupation, sex, age, and industry.

Weighted count

A weighted count represents the proportion of the target population that the responding unit in a survey represents. Users should use the weighted count when creating measures about the larger population from a sample survey.

Standard Application Process

Advisory Committee on Data for Evidence Building. Established by the Evidence Act to review, analyze, and make recommendations to the Office of Management and Budget (OMB) on how to promote the use of federal data for evidence building. Consists of experts from federal, state, and local governments and the private sector who represent multiple areas of expertise, such as privacy, technology, and research methods.

An individual with approval to use confidential data to perform exclusively statistical activities on an approved project, subject to appropriate control, supervision, and agreement to comply with all relevant legal provisions.

Allowed use
Use that is consistent with the privacy notices or informed consent statements used when the data were collected or acquired.

Authorization level
A four-tiered framework for evaluating applications for access to confidential data assets. Agencies are required to provide the authorization level necessary for access to every confidential data asset.

Confidential Information Protection and Statistical Efficiency Act. Establishes uniform confidentiality protections for information collected for statistical purposes by U.S. statistical agencies and allows some data sharing between agencies.

Confidential data; also, sensitive data or confidential data assets
A data asset held under confidentiality that may be accessed only by an agent designated by a statistical agency or unit for an exclusively statistical activity. Such data include surveys of businesses and households, linked employer-employee data, and administrative records from federal and state agencies.

Data asset
A collection of data elements or data sets that may be grouped together.

Information produced as a result of statistical activities conducted for a statistical purpose.

Evidence-building activity
Use of data to assess conditions, characteristics, and behaviors of the public and operations and outcomes of public programs and policies. SAP applications for access to confidential data should be in the service of evidence building.

Evidence Commission  
Established in 2016 by Congress to develop a strategy for increasing the availability and use of data in order to build evidence about government programs, while protecting privacy and confidentiality.

Federal data ecosystem; also, federal statistical system 
A decentralized statistical system with some coordination focused on agency-specific missions.

Federal Statistical Research Data Centers. A network of secure physical and virtual enclaves that allow authorized users to link data from multiple sources; oversight by Census Bureau.

Interagency Council on Statistical Policy. Entity with statutory role in advising OMB on SAP development. Chaired by OMB’s Chief Statistician and comprises the heads of all 16 principal statistical agencies and a rotating member from one of the statistical programs within other federal agencies.

Lead agency
Statistical agency or unit that coordinates the review of an application requesting confidential data from multiple statistical agencies or units or commingled data.

Linked data
Data assets that result from joining two or more data assets across common elements.

Nonstatistical purpose
Use of data in identifiable form for any purpose that is not a statistical purpose, including any administrative, regulatory, law enforcement, adjudicatory, or other purpose that affects the rights, privileges, or benefits of a particular identifiable respondent.

National Secure Data Service. Recommended for establishment by the Evidence Commission and ACDEB as a new entity that could facilitate data access, enable data linkages, and develop privacy-enhancing techniques in support of increasing data availability for evidence building across the entire evidence-building ecosystem.

Principal statistical agency
One of 13 federal agencies or agency components that have statistical work as their principal mission.

Project proposal
Scope of statistical activities proposed by an agent or potential agent using confidential data.

Public data asset
A data asset, or part of an asset, maintained by the federal government that has been, or may be, released to the public, including any data asset, or part thereof, subject to disclosure under the Freedom of Information Act.

SAP metadata asset inventory and agency content pages for 16 federal statistical agencies and units. This online portal houses the SAP; also called “metadata repository.”

Restricted use; restricted access    
Data security protocols and access restrictions governing use of confidential government data for evidence-building purposes.

Standard application process. A common application for applying for access to confidential government statistical data sets for authorized uses.

Statistical activity
Collection, compilation, processing, or analysis of data for the purpose of describing or making estimates concerning the whole, or relevant groups or components within, the economy, society, or the natural environment.

Statistical agency or unit
Agency or organizational unit of the executive branch whose activities predominantly consist of the collection, compilation, processing, or analysis of information for statistical purposes.

Statistical purpose
Description, estimation, or analysis of the characteristics of groups, without identifying individuals or organizations that make up such groups.