System Components
The visible and behind-the-scenes parts of MARCUS, explained in plain language for clinicians.
MARCUS combines a document workspace, evidence search, answer drafting, and citation review. This page names each component, what it does, and what it does not prove.
Technical terms appear in parentheses after the plain-language name. You do not need the technical term to use MARCUS, but it can help when reporting a problem or reviewing system documentation.
Audience
This page is for any clinician or institutional user who wants to understand what happens between adding a source and receiving a cited answer. Project owners, administrators, reviewers, and safety teams may also use it when investigating unexpected results.
Availability
The core document and question workflow is available to authorized workspace users. Specific components may be:
- Permission-dependent: visible only to users with the required organization or project access;
- Configuration-dependent: enabled only for some organizations or deployments; or
- Automatic: part of the system but not directly controlled by a clinician.
Knowledge pages, evidence matrices, theme analysis, sharing, analytics, integrations, and administrative controls are examples of features whose availability can depend on permissions or configuration.
System overview
How MARCUS connects a question to institutional evidence
The main path begins in the clinician's selected workspace and ends with an answer that points back to its sources.
Clinical question
The clinician asks within the selected project.
Access check
MARCUS confirms the organization and project the clinician may use.
Project source set
MARCUS reviews searchable passages from the permitted sources in scope.
Evidence-led answer
Relevant passages are organized into a focused response.
Citations
References connect the answer to source details and pages when available.
Reviewable
Components You See
| Plain-language component | Technical term | What it does | Availability |
|---|---|---|---|
| Sign-in and session | Authentication and session management | Identifies the signed-in user and keeps the application session active | Available to registered users; sign-in method may depend on organization configuration |
| Institutional space | Organization or tenant | Holds memberships, projects, and organization-level settings while separating one organization's data from another's | Requires organization membership |
| Library workspace | Project | Defines a focused working area for sources, conversations, and evidence review | Requires project visibility; editing is permission-dependent |
| Workspace document list | Project source set or source inventory | Shows the documents attached to one project and their processing state | Read access required; adding, replacing, or removing sources requires write access |
| Cross-project source explorer | Library page | Searches and inspects accessible indexed sources across the current organization | Permission-dependent; views and filters may vary by configuration |
| Source overview | Briefing and enrichment | Summarizes one source and may show key points, document type, concepts, or provenance fields | Automatic after processing; some fields may be unavailable or incomplete |
| Question and answer space | Conversation and composer | Accepts a question, shows processing updates, streams the draft answer, and keeps conversation history | Workspace access required; history visibility follows access rules |
| Evidence links | Citations and source viewer | Connects answer statements to supporting passages and source details | Available when the answer includes reviewed supporting evidence |
| Cross-document analysis | Knowledge pages, knowledge graph, themes, and evidence matrices | Summarizes or compares information beyond one answer | Permission- and configuration-dependent |
| Collaboration controls | Members, invitations, project access, collections, and sharing | Determines who can see, change, group, or share material | Usually owner-, admin-, or write-access dependent |
| Usage oversight | Analytics and cost views | Shows selected operational or usage information | Restricted to authorized roles and may not be enabled |
| Guidance | Help Center and documentation | Explains product use, limitations, and troubleshooting | Documentation is public; in-app Help requires application access |
Components Working Behind The Scenes
| Plain-language component | Technical term | What it does | What clinicians should know |
|---|---|---|---|
| Web interface | Frontend | Displays the application, sends requests, and renders streamed answers and citations | A visible page does not prove that a requested backend action succeeded; check the resulting state |
| Application service | Backend or API | Checks access, coordinates sources and conversations, and returns data to the interface | Access is checked before project data is used |
| Access boundary | Authorization and tenant/project scoping | Limits each request to the allowed organization, project, and action | Never use an unexpected result as permission to view or share it; report possible scope errors |
| Original-file storage | Object storage | Holds approved uploaded source files | Only approved non-PHI material may be stored |
| Source preparation | Ingestion and indexing | Extracts text, divides it into passages, prepares search records, and marks the source searchable only after required checks complete | A source that is still processing or has failed is not ready for evidence review |
| Source analysis | Enrichment | Produces a briefing and may identify document type, key points, concepts, and provenance fields | Generated metadata supports inspection but does not replace reading the source |
| Evidence and history store | Database and search index | Holds organizations, projects, source records, passages, search representations, conversations, citations, and related records | The active organization and project remain important boundaries |
| Background work service | Worker and job queue | Performs longer-running source preparation outside the immediate page request | Processing can continue after an upload page changes; use the displayed status to verify completion |
| Evidence search | Hybrid retrieval | Searches prepared passages by exact wording and semantic meaning within the allowed scope | Search can miss relevant wording, and an incomplete source set produces incomplete evidence |
| Result ordering | Reranking, diversity selection, and context ordering | Prioritizes passages that appear most relevant and reduces repetitive evidence before drafting | Ranking is useful but not a clinical authority decision |
| Answer drafting | Generation with a language model | Uses the question and selected passages to compose a readable draft | The model can omit, overstate, or poorly connect evidence; citations require human review |
| Fast repeat handling | Response cache | May reuse a recent supported response when the project context and similarity rules allow it | A faster answer is not a stronger answer; review it the same way |
| Operational records | Audit, analytics, cost, and telemetry records | Supports operation, review, reliability, and authorized oversight | Visibility and completeness vary; these records are not a clinical record |
| External processing services | Configured search and answer services | May process approved document text, passages, questions, or generated content as part of search preparation and answer drafting | This is another reason the non-PHI rule applies to both sources and questions |
Key Workflow: How A Source Becomes Searchable
- An authorized user adds an approved non-PHI document to a library workspace.
- MARCUS records the source and stores the original file.
- Source preparation extracts readable text and divides it into smaller passages.
- Search preparation creates records that support exact-language and meaning-based matching.
- Source analysis may create a briefing, key points, concepts, document-type cues, and source evidence labels.
- MARCUS checks that the expected passages and searchable records were prepared.
- Only then does the source reach a searchable ready or indexed state.
If part of the process fails, MARCUS may show a failure or partial state. Do not treat the document as fully available until the source state confirms readiness.
Key Workflow: How A Question Becomes A Cited Draft
- The web interface sends the non-PHI question with the selected workspace context.
- The application service confirms the user's session and access.
- MARCUS fixes the allowed source scope for that request.
- Evidence search reviews prepared passages using exact wording and meaning-based matching.
- Result ordering prioritizes useful passages and removes some duplication.
- The selected passages form the evidence packet used for drafting.
- The answer-drafting model composes a response while preserving source information for citations.
- The interface streams the draft, citations, and any available follow-up controls.
- The user opens the citations and decides whether the evidence supports the draft.
For example, a question such as “What does the approved transfer policy require before handoff?” should be answered from the selected project's approved indexed sources. The wording of the answer is generated; the supporting policy remains the authority.
Expected Result And Verification
For a successfully prepared source, verify:
- the source appears in the intended project's source set;
- its state is ready or indexed rather than queued, processing, failed, or partial;
- its title and source details identify the expected document; and
- its briefing or extracted details are consistent with the source, when those features are available.
For a successfully evidence-linked answer, verify:
- the intended organization and workspace were active;
- the answer addresses the question without introducing unsupported patient-specific assumptions;
- important claims have citations;
- each opened citation supports the nearby claim;
- the source is authoritative, current, and locally applicable; and
- gaps or conflicts are acknowledged rather than silently resolved.
The visible completion of a streamed answer confirms that drafting ended. It does not confirm that the answer is complete, clinically correct, or supported in every detail.
Common Problems
A source remains in processing
Long or complex files can take longer to prepare. Refresh the source view and inspect the latest status. If it remains unchanged or reports failure, use the documented retry path or contact an authorized project owner or administrator.
A source is ready but the answer does not cite it
Confirm the active workspace and use wording from the document title, section heading, or local terminology. Then inspect the source directly. Search and ranking are not guaranteed to select every relevant passage.
A citation opens but does not support the full statement
Treat the unsupported portion as unverified. Check adjacent citations and the original document. Restate the question more narrowly if needed, and report recurring citation mismatch.
The answer combines conflicting documents
Open each citation, compare version and provenance fields, and ask a narrower question that requests the disagreement explicitly. MARCUS should not be used to silently decide which institutional source overrides another.
An advanced component is missing
Knowledge, sharing, integrations, analytics, and administrative tools can depend on configuration and permissions. Their absence is not evidence of a processing failure.
Safety Note: Institutional Non-PHI Workspace
There is currently no PHI lane in MARCUS. Do not enter, upload, paste, connect, or transmit PHI, patient identifiers, patient-specific clinical facts, credentials, secrets, or other prohibited data. This applies to documents, pasted text, questions, connector selections, filenames, source metadata, conversations, and shared outputs.
Use only approved institutional non-PHI material. MARCUS may send approved text and questions to configured processing providers, so removing only a patient's name is not enough to make patient-specific content acceptable.
Continue
- Previous: Clinician Handbook
- Next: Workspace and access
- Related: Adding your first source, Asking your first question, and How MARCUS reviews sources