Direct comparison
tDAR vs Open Context: Repository Guide
Compare tDAR and Open Context for archaeology data: preservation vs. publication model, access tiers, licensing, fees, and which fits your project.
Side-by-side comparison
| Dimension | tDAR | Open Context |
|---|---|---|
| Full name | the Digital Archaeological Record | Open Context (platform name; not an acronym) |
| Managing organization | Center for Digital Antiquity, Arizona State University (School of Human Evolution and Social Change) | Alexandria Archive Institute, an independent 501(c)(3) nonprofit |
| Launched | Production repository from 2008-2009 (Digital Antiquity formally organized 2009), following Mellon-funded transition from prototype | Launched 2006 |
| Start-up funding | National Science Foundation and the Andrew W. Mellon Foundation | Alexandria Archive Institute, supported over time by grant funding for individual projects |
| Core model | Preservation-first repository for the long-term curation of archaeological records, especially CRM grey literature | Data-publishing platform focused on structured, linked, citable publication of primary field data |
| Long-term custody | Direct -- formal Memorandum of Agreement transfers custody to ASU Library if Digital Antiquity cannot continue operating tDAR | Indirect -- archived via UC’s California Digital Library Merritt repository and Zenodo; images mirrored via Internet Archive |
| Access controls | Supports restricted/confidential access tiers alongside public records, commonly used to protect sensitive data such as site locations | Published records are open by default; sensitive details (e.g., precise locations) are generalized or redacted by the project team before publication |
| Licensing | Governed by tDAR terms of use; not a single blanket Creative Commons license | Creative Commons licensing throughout -- an early adopter of CC in archaeology, with explicit reuse rights stated per record |
| Fees | Deposit/subscription fees apply for uploading collections, per Digital Antiquity’s fee schedule | One-time data publishing and archiving fee charged to the depositing project; free for end users to access and reuse data |
| CoreTrustSeal | CoreTrustSeal certified | No public CoreTrustSeal certification identified |
| Typical content | Datasets, GIS/spatial data, images, technical/CRM compliance reports, documents, coding sheets | Structured tabular datasets, field notes, images, 3D models, maps -- linked to controlled vocabularies |
| APIs / linked data | Web search interface; more limited API surface than Open Context | Extensive APIs and linked-open-data structure integrating external vocabularies (e.g., Getty AAT, Periodo) for cross-project querying |
| Typical depositor | US-based CRM firms, agencies, and universities preserving compliance-driven records | Individual excavation/survey projects seeking structured, citable publication of primary field data |
Common questions
FAQ
Can the same archaeological dataset go in both tDAR and Open Context?+
Yes. A common pattern is to publish a structured, citable dataset through Open Context for discovery and reuse, and separately deposit the fuller project archive -- raw files, reports, and any restricted materials -- in tDAR for long-term preservation. The two are complementary, not mutually exclusive.
Is either repository required for US cultural resource management (CRM) compliance reporting?+
Neither is universally mandated by federal regulation, but tDAR functions as the de facto standard many CRM firms and agencies use to archive Section 106-related grey literature, in part because of its ASU Library succession agreement for long-term custody.
Is data on tDAR and Open Context free to access?+
Yes for both -- end-user access to published data is free. Where fees apply, they are charged to the depositing project or institution, not to researchers retrieving data.
Do tDAR and Open Context assign persistent identifiers?+
Both platforms assign stable, citable identifiers to published records so datasets can be referenced in publications. Check each platform’s current citation guidance for the exact identifier format before citing a specific record.
Going deeper
