How to compare asserted works with disputed materials for Copyright Infringement Matters

Compare asserted works with disputed materials by fixing the exact versions, identifying the asserted right, and mapping each disputed passage, image, sequence, or code segment to its alleged source. Record differences alongside similarities, distinguish potentially protected expression from excluded subject matter, and keep permissions and use context visible. The deliverable is a source-linked work comparison matrix: counsel’s analytical record showing what corresponds, what differs, which conclusions remain uncertain, and what evidence or legal analysis is needed before advancing or challenging an infringement position.

When to use this workflow

Use this workflow when litigation counsel or an in-house team receives an infringement demand, evaluates produced materials, prepares an infringement position, or tests an expert’s proposed comparisons. It is particularly useful when a demand identifies an entire work but alleges copying of selected elements, or when revisions make the comparison baseline uncertain.

This guide addresses US copyright law and references federal evidence rules. Those procedural references do not automatically govern state proceedings, arbitration, or Copyright Claims Board matters. Identify controlling authority for the work category, forum, and procedural posture before applying a similarity test.

Keep the assignment bounded. Ownership, registration, remedies, and discovery may require separate analysis; this deliverable concerns identifiable comparisons and their supporting evidence.

What you need

Collect these inputs before substantive comparison:

• Asserted works: complete copies, native creative files where available, relevant revisions, registration deposits if supplied, and publication records identifying the claimed version.
• Disputed materials: complete files or captures, surrounding pages or sequences, distribution context, collection information, and available version history.
• Allegations: demand letters, pleadings, schedules of works, identified defendants, alleged acts, dates, and asserted rights.
• Context records: permissions, licenses, attribution, source acknowledgments, creation communications, and evidence concerning access or independent development.
• Review instructions: work categories, disputed issues, controlling-authority questions, confidentiality restrictions, and the lawyer responsible for decisions.

Maintain untouched originals and separate working copies. An annotated or cropped comparison must not silently replace its source. Assign stable document IDs and maintain a source inventory recording filenames, versions, custodians or collection sources, and known dates. Distinguish a capture date from the date the depicted material allegedly became available.

Use the template

The companion template is Copyright Infringement Matters — Work comparison matrix. You can copy this table into your working document or spreadsheet. Keep the source inventory and linked legal notes alongside it.

Create separate rows for meaningful comparisons within each asserted-work, defendant, act, and right combination. Repeat the combination identifier when several passages require separate treatment. This prevents one conspicuous match from obscuring weaker allegations elsewhere.

The source columns need document IDs, versions, and precise locations: page and paragraph, timestamp range, frame number, or file path and line range. The expression field identifies the feature requiring legal analysis, not a conclusory “protected” label. The context field captures permissions, surrounding use, competing explanations, and unavailable evidence. The final field states the current decision, its reason, and an accountable owner; link longer reasoning by note ID.

Step by step

1. Define the allegation and comparison unit

Translate the allegation into a specific proposition: which defendant allegedly did what, to which work, through which disputed material? Separate reproduction from alleged adaptation, distribution, public performance, or public display. Record the allegation’s period so later versions or permissions do not silently change the baseline.

Section 106 enumerates exclusive rights, subject to statutory limitations; § 102(b) excludes ideas, procedures, systems, and similar subject matter from protection. Resemblance alone therefore identifies neither the implicated right nor protectable material. These provisions do not supply a universal substantial-similarity test. See 17 U.S.C. §§ 102 and 106. (copyright.gov)

Enter the defendant, act, and right in the matrix. If the allegation is unclear, label counsel’s proposed characterization as a working hypothesis and assign clarification.

2. Fix versions and verify the comparison sources

Determine whether each file is the alleged original, a later revision, a publication copy, or an incomplete extract. Check identifiers against the allegation and supporting records. A registration deposit, website capture, and editable source file may contain different material; compare them before treating them as interchangeable.

Record provenance and identify who can explain each item. In federal proceedings, Evidence Rule 901(a) requires sufficient evidence that an item is what its proponent claims; Rule 602 generally requires a foundation for a witness’s personal knowledge. Authentication does not resolve hearsay or other admissibility questions. See Federal Rules of Evidence, Rules 602 and 901. (uscourts.gov)

Enter the identified version and pinpoint in each source field. Put unresolved provenance questions in “Context / gaps.” Record what was verified rather than treating possession of a file as verification of its history.

3. Map corresponding material without losing context

Review complete works before selecting candidate correspondences. For prose, map passages and their surrounding argument. For photographs or illustrations, identify composition, placement, and depicted elements. For audiovisual material, record sequences and timestamps. For software, identify files, functions, and line ranges rather than isolated terms alone.

Use side-by-side working copies, but disclose cropping, resizing, transcription, speed changes, or other transformations. Check OCR against the source image and timestamps against the identified media version. Retain enough surrounding material for another reviewer to reproduce the comparison.

Record similarities and differences in the same row: omitted passages, altered wording, changed sequence, different visual treatment, or changed functionality. Describe observable features first. A matching segment and an inference about how it arose belong in distinct analytical statements.

4. Separate expression questions from raw resemblance

Identify precisely what counsel contends is expressive: particular wording, visual arrangement, a sequence, or another specified feature. Separately flag ideas, procedures, systems, and other potentially excluded material for analysis under § 102(b). See 17 U.S.C. § 102(b). (copyright.gov)

Do not assume every difference defeats an allegation or every repeated element supports it. Assign narrow research questions concerning the identified feature and work category rather than importing a test from an unrelated medium. Keep any feature-level assessment provisional until counsel checks the governing approach and appropriate comparison scope.

Record the proposed expressive feature, competing characterization, and authority question. If automated similarity scores are used, retain them only as review aids; they are not substitutes for this analysis.

5. Test context, permission, and alternative explanations

Read beyond the matched segment. Identify commentary, attribution, surrounding content, and the disputed use’s purpose. Link asserted permission to its supporting records, covered work, relevant right, and period. Do not assume that the absence of a formal license document resolves every possible authorization argument.

Where fair use is raised, organize evidence around purpose and character, nature of the copyrighted work, amount and substantiality used in relation to the whole, and effect on the potential market or value. These statutory factors require contextual analysis; a checklist or listed example does not automatically establish fair use. See 17 U.S.C. § 107. (copyright.gov)

Record supporting and adverse context, including common-source or independent-development explanations. Identify the evidence behind each explanation. Distinguish unavailable records from records affirmatively contradicting a position.

6. Challenge the comparison and assign remaining work

Have another reviewer reconstruct significant rows from cited sources without relying on the first reviewer’s annotations. Ask whether excerpts exaggerate resemblance, contrary portions were omitted, or a version mismatch changes the result. Check the complete-work context as well as individual rows.

Separate observed correspondence, an inference of copying, and a proposed legal conclusion. Assign targeted follow-up: obtain the complete animation, investigate authorization communications, verify a publication copy, or research treatment of an identified feature. Avoid turning every uncertainty into an unrestricted collection request.

Update the decision field with the current position, reason, reviewer, and remaining task. Preserve superseded decisions in linked notes when new evidence materially changes the analysis.

7. Prepare a reviewable analytical deliverable

Provide the matrix, source inventory, annotated working comparisons, and a short list of unresolved decisions. Classify rows as supporting further investigation, a proposed argument, or exclusion from the current position. Do not force unresolved comparisons into binary infringement findings.

Keep the internal matrix distinct from a proposed court exhibit. Federal Evidence Rule 1006 addresses summaries of voluminous admissible materials that cannot conveniently be examined in court, whether or not the underlying materials are introduced. It requires access to originals or duplicates for examination or copying. A chart functioning only as an illustrative aid falls under Rule 107 instead. See Federal Rules of Evidence, Rules 107 and 1006. (uscourts.gov)

Record the intended use and assign separate evidentiary review where needed.

Worked example

Fictional scenario: Alder Finch Studio alleges that Meridian Skills copied portions of its illustrated warehouse-training guide into an online course. All parties, documents, and quoted language below are fictional. The demand identifies guide version 2, but the review folder initially contains version 3. Counsel obtains version 2 and assigns it document ID A01 before comparing content.

The disputed sources are a complete course PDF, D01, and a short animation capture, D02. Correspondence C01 records permission discussions but does not establish their outcome. Counsel records reproduction allegations for the PDF and a provisional public-display allegation for the animation; the capture alone does not establish the circumstances of display.

AF-01 supports focused review of wording, but its brevity makes the protection question important; exact correspondence alone does not resolve it. AF-02 directs counsel away from the shared safety procedure and toward any specific visual arrangement actually alleged. AF-03 cannot support a conclusion about the unseen sequence or the circumstances of public display.

C01 remains relevant to all affected rows. It establishes discussions, not whether permission was granted, refused, limited, or later modified. Counsel assigns that investigation rather than converting an incomplete correspondence file into a definitive authorization finding.

Common mistakes

• Comparing the newest files instead of the alleged versions. Verify the baseline and identify later revisions separately.
• Showing only matching excerpts. Preserve surrounding content and record meaningful differences beside each correspondence.
• Treating a shared idea as asserted expression. Identify the particular feature and assign work-specific legal analysis.
• Inferring access from resemblance alone. Separate resemblance from independently sourced access evidence and competing explanations.
• Treating missing permission records as a definitive denial. Record the search scope, available communications, and unresolved authorization arguments.
• Reusing the matrix as an exhibit without review. Separate analytical annotations from underlying evidence and assess the intended evidentiary function.

Final quality check

• Every row identifies the work, disputed material, defendant, act, and asserted right.
• Source IDs resolve to preserved files with identified versions and provenance limitations.
• Page, frame, timestamp, or code references reproduce the stated comparison.
• Similarities, differences, and surrounding context are accurately described.
• Expression questions and legal conclusions are distinct; governing authority is checked or assigned.
• Permissions, fair-use context, and alternative explanations include available adverse evidence.
• Material conclusions have been verified against sources; open issues are resolved or explicitly assigned.
• Internal, illustrative, and proposed evidentiary uses are clearly distinguished.

Complete the workflow with DecoverAI

DecoverAI is the Legal Intelligence Platform for litigation and transactions. Its litigation document review and evidence analysis capabilities can support this source-backed comparison workflow; tabular review supports work across multiple documents. Counsel remains responsible for verifying correspondences, selecting controlling authority, and assessing legal significance. Explore litigation preparation capabilities or book a demo to discuss this workflow. (decover.ai)

Frequently asked questions

Should each asserted work have only one row?

No. Separate materially different passages, features, defendants, acts, or rights. Retain a common work identifier and a linked whole-work assessment so individual rows do not fragment the legal analysis.

Can a similarity percentage rank the strongest allegations?

Not reliably by itself. It does not resolve the expression question, governing test, permission, or use context. Use a score, if available, to locate candidates for review, then verify the sources and explain significance independently.

What if only screenshots or excerpts are available?

Record exactly what they show and their limits. Identify missing complete works, versions, provenance, and surrounding content. Assign collection or verification before drawing conclusions about unseen pages or sequences.

Should fair use and licensing stay outside the comparison?

Detailed analysis can sit in linked notes, but retain relevant context in each affected row. Otherwise, a persuasive visual comparison may circulate without the authorization or use facts necessary to evaluate the position.

Sources

• US Copyright Office: Copyright Act, Chapter 1, §§ 102, 106, and 107.
• US Courts: Federal Rules of Evidence, Rules 107, 602, 901, and 1006.

Scope: General professional workflow guidance using the supplied October 13, 2026 research cutoff; matter-specific conclusions require the actual evidence and applicable authority.

This guide is general information about legal workflows, not legal advice for any matter. It was drafted and reviewed with AI assistance. The worked example is fictional. Contract rights and procedure depend on the governing law, the actual wording, and the facts, so check the cited sources and the rules that apply in your jurisdiction before relying on it.