Plan and prepare
Inventory files that need unusual software, an old device, or an online account to open. Begin with material that would be difficult to replace. Record each format, the software currently used, and any features that matter, such as formulas, captions, layers, page layout, or embedded attachments.
Choose a few representative files for a conversion trial. Keep the originals unchanged and place converted copies in a separate folder. A widely supported format may make access easier, but no conversion should be assumed to preserve every feature. Decide which properties must survive before choosing the output.
Use a clear process
Compare the result with the original while both can still be opened. For a text document, check headings, characters, tables, and page sequence. For a spreadsheet, inspect values and formulas rather than judging only the visible first sheet. Record any features that changed or were intentionally omitted.
Write a conversion note containing source and destination filenames, tool and version, date, settings that mattered, and the review result. Create checksums for both versions where your archive uses them. A changed checksum is expected after conversion; it should be explained by the record rather than treated as accidental damage.
Worked example
Suppose an old project document opens only in software the current team rarely uses. A trial might produce a readable PDF for access while retaining the original editable file. Before conversion, list the properties that matter: all pages, readable text, tables, embedded images, and any comments the archive intends to preserve. Compare those properties deliberately. If comments disappear, the project can retain a separate export or keep the original as the only complete version, documenting the limitation of the access copy rather than describing it as an exact replacement.
Decisions and exceptions
Choose test files that represent the difficult parts of the collection, not only the simplest example. Include a document with unusual characters, one with a complex table, and one with an attachment if those features occur. Record the viewer used during comparison. A file that appears correct in the conversion program may behave differently in the reader intended for future users. Avoid running a large automatic conversion until the trial establishes which features survive and which need separate handling or specialist advice.
Check and improve
Create a migration decision record that explains why the change was made and what was preserved. Link the original and converted identifiers so users can find both versions. Keep the tool settings and review criteria with the maintenance documentation, then check a sample after copying the results to their final location. If the project later repeats the process with a new tool or software version, treat it as another trial rather than assuming identical behavior. The aim is continued understandable access while retaining enough evidence to revisit decisions when better tools, knowledge, or requirements become available.
Solo and community application
Alone, convert a small sample and test it on a second available reader before processing a whole collection. A community archive can assign one person to prepare copies and another to review a sample against agreed criteria. Retain the original files even when the access copies appear satisfactory, subject to the collection's policy.
Reference guidance
Library of Congress preservation guidance includes information about software, formats, versions, and file history. This trial-and-comparison workflow is a practical application. Schedule future review based on actual access problems and software changes, and keep the archive's reading instructions current so migration does not create another undocumented dependency.