Core Documents

Commentaries to the Guidelines for Practice

Commentary 16 - Justification

  1. Rationale
    • Examination and scientific investigation involve procedures with consequences which are usually known and quantifiable. However, some procedures may have consequences which are not presently known or suspected. Thus, to prevent unnecessary procedures, and therefore, reduce risks, the conservation professional should establish the necessity of all such activities prior to carrying them out.
    • Such procedures are commonly used to:
      • evaluate physical condition or perform a risk asssessment;
      • design a conservation treatment;
      • support art historical, anthropological or historical research aims (e.g., artist's techniques and materials);
      • carry out provenance and authenticity studies;
      • characterize a previous conservation intervention;
      • understand the aging properties or alterations of materials.
  2. Minimum Accepted Practice
    • Conservators routinely carry out examination procedures for condition assessment and for the preparation of a treatment plan. Many of these procedures may have a small physical effect on the cultural property, but are not considered to have sufficient effect to require separate justification. These include:
      • solvent testing of resinous surface coatings;
      • pH testing of paper and textiles;
      • removal of proportionately insignificant samples for visual inspection and microchemical testing;
      • temporary, non-destructive removal of an architectural element to allow inspection.
      • The conservator must exercise discretion especially in these situations.
    • The justification for examination /scientific investigation procedures must be documented in written form when there is a potential for significant alteration of the cultural property. This documentation must include:
      • all items as required in Guideline 24, Documentation;
      • location on cultural property where examination/scientific investigation procedures are to be performed;
      • types of information sought;
      • a description of all procedures to be used, including all personnel involved;
      • sampling strategy;
      • likelihood that selected procedures will provide information sought.
    • If an invasive procedure (e.g., sampling) is to be used, the conservation professional must explain why a non-invasive procedure would be insufficient.
    • If the proposed procedure is not in common use in conservation, a more complete description and justification is required.
    • If any procedure used for examination or scientific investigation influences the validity of a possible subsequent procedure (e.g. effect of x-radiography on thermoluminescence dating), the decision to continue with the former procedure must be justified in light of the hampered subsequent one.
    • Justification for sampling, testing, or scientific investigation must be submitted in writing to the owner/custodian and written permission obtained prior to performance of the work. All justifications for examination and scientific investigation must become components of Documentation.
  3. Recommended Practice
    • Justification for examination and scientific investigation may include references to techniques and protocols, preferably from a literature source.
    • Justification for the use of experimental techniques or those less frequently encountered in the literature should also include a minimum of one second opinion, preferably from an expert in a relevant field.
  4. Special Practice
    • In rare circumstances when physical access is limited to a single opportunity, and unexpected materials are encountered, sampling may be carried out without prior written justification. In these circumstances, the sampling must still be justifiable under the criteria presented above, and a written justification should be prepared after the sampling.


Approved by the AIC Board October 1998.