Identification Guidelines


These Guidelines link the Standards for Identification with more specific guidance and technical information. The Guidelines outline one approach to meet the Standards for Identification. Agencies, organizations and individuals proposing to approach identification differently may wish to review their approaches with the National Park Service.

The Guidelines are organized as follows:
Role of Identification in the Planning Process
Performing Identification
Integrating Identification Results
Reporting Identification Results
Recommended Sources of Technical Informtion [Note: The technical information is outdated and not included here.]

Role of Identification in the Planning Process

Identification is undertaken for the purpose of locating historic properties and is composed of a number of activities which include, but are not limited to archival research, informant interviews, field survey and analysis. Combinations of these activities may be selected and appropriate levels of effort assigned to produce a flexible series of options. Generally identification activities will have multiple objectives, reflecting complex management needs. Within a comprehensive planning process, identification is normally undertaken to acquire property-specific information needed to refine a particular historic context or to develop any new historic contexts. (See the Guidelines for Preservation Planning for discussion of information gathering to establish plans and develop historic contexts.) The results of identification activities are then integrated into the planning process so that subsequent activities are based on the most up-to-date information. Identification activities are also undertaken in the absence of a comprehensive planning process, most frequently as part of a specific land use or development project. Even lacking a formally developed preservation planning process, the benefits of efficient, goal-directed research may be obtained by the development of localized historic contexts, suitable in scale for the project ares, as part of the background research which customarily occurs before field survey efforts.

Performing Identification

Research Design

Identification activities are essentially research activities for which a statement of objectives or research design should be prepared before work is performed. Within the framework of a comprehensive planning process, the research design provides a vehicle for integrating the various activities performed during the identification process and for linking those activities directly to the goals and the historic context(s) for which those goals were defined. The research design stipulates the logical integration of historic context(s) and field and laboratory methodology. Although these tasks may be performed individually, they will not contribute to the greatest extent possible in increasing information on the historic context unless they relate to the defined goals and to each other. Additionally, the research design provides a focus for the integration of interdisciplinary information. It ensures that the linkages between specialized activities are real, logical and address the defined research questions. Identification activities should be guided by the research design and the results discussed in those terms. (See Reporting Identification Results.)

The research design should include the following:

1. Objectives of the identification activities. For example: to characterize the range of historic properties in a region; to identify the number of properties associated with a context; to gather information to determine which properties in an area are significant. The statement of objectives should refer to current knowledge about the historic contexts or property types, based on background research or assessments of previous research. It should clearly define the physical extent of the area to be investigated and the amount and kinds of information to be gathered about properties in the area.

2. Methods to be used to obtain the information. For example: archival research or field survey. Research methods should be clearly and specifically related to research problems.

Archival research or survey methods should be carefully explained so that others using the gathered information can understand how the information was obtained and what its possible limitations or biases are. The methods should be compatible with the past and present environmental character of the geographical area under study and the kinds of properties most likely to be present in the area.

3. The expected results and the reason for those expectations. Expectations about the kind, number, location, character and condition of historic properties are generally based on a combination of background research, proposed hypotheses, and analogy to the kinds of properties known to exist in areas of similar environment or history.

Archival Research

Archival or background research is generally undertaken prior to any field survey. Where identification is undertaken as part of a comprehensive planning process, background research may have taken place as part of the development of the historic contexts (see the Guidelines for Preservation Planning). In the absence of previously developed historic contexts, archival research should address specific issues and topics. It should not duplicate previous work. Sources should include, but not be limited to, historical maps, atlases, tax records, photographs, ethnographies, folklife documentation, oral histories and other studies, as well as standard historical reference works, as appropriate for the research problem. (See the Guidelines for Historical Documentation for additional discussion.)

Field Survey

The variety of field survey techniques available, in combination with the varying levels of effort that may be assigned, give great flexibility to implementing field surveys. It is important that the selection of field survey techniques and level of effort be responsive to the management needs and preservation goals that direct the survey effort.

Survey techniques may be loosely grouped into two categories, according to their results. First are the techniques that result in the characterization of a region's historic properties. Such techniques might include "windshield" or walk-over surveys, with perhaps a limited use of sub-surface survey. For purposes of these Guidelines, this kind of survey is termed a "reconnaissance." The second category of survey techniques is those that permit the identification and description of specific historic properties in an area; this kind of survey effort is termed "intensive." The terms "reconnaissance" and "intensive" are sometimes defined to mean particular survey techniques, generally with regard to prehistoric sites. The use of the terms here is general and is not intended to redefine the terms as they are used elsewhere.

Reconnaissance survey might be most profitably employed when gathering data to refine a developed historic context—such as checking on the presence or absence of expected property types, to define specific property types or to estimate the distribution of historic properties in an area. The results of regional characterization activities provide a general understanding of the historic properties in a particular area and permit management decisions that consider the sensitivity of the area in terms of historic preservation concerns and the resulting implications for future land use planning. The data should allow the formulation of estimates of the necessity, type and cost of further identification work and the setting of priorities for the individual tasks involved. In most cases, areas surveyed in this way will require resurvey if more complete information is needed about specific properties.

A reconnaissance survey should document:

  1. The kinds of properties looked for;
  2. The boundaries of the area surveyed;
  3. The method of survey, including the extent of survey coverage;
  4. The kinds of historic properties present in the surveyed area;
  5. Specific properties that were identified, and the categories of information collected; and
  6. Places examined that did not contain historic properties.
Intensive survey is most useful when it is necessary to know precisely what historic properties exist in a given area or when information sufficient for later evaluation and treatment decisions is needed on individual historic properties. Intensive survey describes the distribution of properties in an area; determines the number, location and condition of properties; determines the types of properties actually present within the area; permits classification of individual properties; and records the physical extent of specific properties. An intensive survey should document:
  1. The kinds of properties looked for;
  2. The boundaries of the area surveyed;
  3. The method of survey, including an estimate of the extent of survey coverage;
  4. A record of the precise location of all properties identified; and
  5. Information on the appearance, significance, integrity and boundaries of each property sufficient to permit an evaluation of its significance.

Reconnaissance or intensive survey methods may be employed according to a sampling procedure to examine less-than-the-total project or planning area.
Sampling can be effective when several locations are being considered for an undertaking or when it is desirable to estimate the cultural resources of an area. In many cases, especially where large land areas are involved, sampling can be done in stages. In this approach, the results of the initial large area survey are used to structure successively smaller, more detailed surveys. This "nesting" approach is an efficient technique since it enables characterization of both large and small areas with reduced effort. As with all investigative techniques, such procedures should be designed to permit an independent assessment of results.

Various types of sample surveys can be conducted, including, but not limited to: random, stratified and systematic. Selection of sample type should be guided by the problem the survey is expected to solve, the nature of the expected properties and the nature of the area to be surveyed.

Sample surveys may provide data to estimate frequencies of properties and types of properties within a specified area at various confidence levels. Selection of confidence levels should be based upon the nature of the problem the sample survey is designed to address.

Predictive modeling is an application of basic sampling techniques that projects or extrapolates the number, classes and frequencies of properties in unsurveyed areas based on those found in surveyed areas. Predictive modeling can be an effective tool during the early stages of planning an undertaking, for targeting field survey and for other management purposes. However, the accuracy of the model must be verified; predictions should be confirmed through field testing and the model redesigned and retested if necessary.

Special survey techniques

Special survey techniques may be needed in certain situations.

Remote sensing techniques may be the most effective way to gather background environmental data, plan more detailed field investigations, discover certain classes of properties, map sites, locate and confirm the presence of predicted sites, and define features within properties. Remote sensing techniques include aerial, subsurface and underwater techniques. Ordinarily the results of remote sensing should be verified through independent field inspection before making any evaluation or statement regarding frequencies or types of properties.

Integrating Identification Results

The results of identification efforts must be integrated into the planning process so that planning decisions are based on the best available information. The new information is first assessed against the objectives of the identification efforts to determine whether the gathered information meets the defined identification goals for the historic context(s); then the goals are adjusted accordingly. In addition, the historic context narrative, the definition of property types and the planning goals for evaluation and treatment are all adjusted as necessary to accommodate the new data.

Reporting Identification Results

Reporting of the results of identification activities should begin with the statement of objectives prepared before undertaking the survey. The report should respond to each of the major points documenting:
  1. Objectives;
  2. Area researched or surveyed;
  3. Research design or statement of objectives;
  4. Methods used, including the intensity of coverage. If the methods differ from those outlined in the statement of objectives, the reasons should be explained.
  5. Results: how the results met the objectives; result analysis, implications and recommendations; where the compiled information is located.

A summary of the survey results should be available for examination and distribution. Identified properties should then be evaluated for possible inclusion in appropriate inventories.

Protection of information about archeological sites or other properties that may be threatened by dissemination of that information is necessary. These may include fragile archeological properties or properties such as religious sites, structures, or objects, whose cultural value would be compromised by public knowledge of the property's location.

Part of a series of articles titled Secretary of the Interior's Standards and Guidelines for Archeology and Historic Preservation.

Last updated: May 13, 2020