DALICC Requirements & Challenges
The following requirements can be derived for the DALICC system: The system’s output 1) has to comply with applicable laws, 2) needs to correctly interpret obligations and permissions from processed licenses, 3) must preserve abstractness and technological neutrality of the rules, and 4) needs to support the dynamics of the rules under conditions of real world applications and usage. To achieve these goals the following problems need to be addressed:
Problem 1: Tackling license heterogeneity
Is it possible to combine a GPL Documentation License (as used by Wikipedia) with the Italian Open Government Data License v.1? Is CC-BY-ND compatible with UKCROWN? In the creation of derivative works the simplest approach is to only combine content under the same well-known licence. This is over-restrictive though, and many licences under various names may permit their content to be combined. It is, however, difficult to judge, whether it is permitted and how the resultant content should be licensed. There may still be subtleties arising from unclear definitions of terms (i.e. “open” or “commercial use”), special clauses (i.e. share-alike) or implicit preconditions (i.e. “everything not permitted is forbidden” or “CC0 apart from images - see restrictions in further links”).
DALICC aims to resolve these issues by producing machine-readable representations of licenses that allow licenses to be compared to each other in order to identify equivalent licenses and to point the user to potential conflicts. Such an undertaking is time-consuming and requires the cooperation of legal experts and modelling experts. The output itself will be an audited set of machine-readable licenses.
Problem 2: Tackling REL heterogeneity
Combining licences is simpler if all of the licences involved are expressed through the same REL. But as we have seen, various RELs (i.e. MPEG21, ODRL, ccREL) have emerged for various purposes, each providing their own vocabulary and level of expressivity. Hence, it is difficult to compare licenses that have been represented by different RELs. Additionally, it can sometimes be reasonable to extend the semantic expressivity of a given REL by adding expressions from another REL to cover the requirements of a real world scenario.
DALICC will solve this problem by applying a semantic web approach to represent RELs, map their terms to each other and extend their expressivity. It will represent existing vocabularies from various RELs by utilizing semantic web standards like RDF and OWL, thus allowing mappings between various RELs to be created. Additionally, this approach allows vocabulary terms from various RELs to be combined and their expressivity to be extended beyond their original scope. The latter aspect is necessary to tackle the issues raised in the section above (Problem 1). The output from this undertaking is the basis for the reasoning engine described in the next section.
Problem 3: Compatibility check, conflict detection & neutrality of the rules
A regular problem with semantic translation between schemas (such as RELs) is in making sure that the meaning of different terms are aligned. The regular problems are in demonstrating the equivalence of classes, properties and instances. For RELs the major problem is for the instances, i.e. the precise definitions of “non-commercial”, "distribution", "share-alike" etc. The classes and properties are usually simple concepts and very similar. Not all RELs support all classes though: some ignore “Jurisdiction” or even “End-user”, according to the needs of the market they were developed for. To a certain degree this will be resolved by applying Semantic Web standards, but mapping alone won’t solve the issue. More elaborated techniques like reasoning and inferencing mechanisms are necessary to improve the precision of conflict detection.
To solve these issues DALICC will create a reasoning engine that provides users with guided assistance in the detection of conflicts in accordance with specific usage scenarios of an envisioned application. In other words, DALICC will assist users with a workflow specifying the usage context, thus collecting supplementary information that helps to detect ambivalent concepts and potential conflicts. Based on this information the DALICC reasoning engine will reason over the set of licenses and infer instructions for the end-user on how to proceed in the license clearance process.
Problem 4: Legal validity of representations and machine recommendations
The semantic complexity of licensing issues means that the semantics of RELs must be clearly aligned within the specific application scenario. This includes a correct interpretation of the various national legislations according to the country of origin of a jurisdiction (i.e. German Urheberrecht vs. US copyright), the resolution of problems that are derived from multilinguality (i.e. multiple connotations of “royalities” within German jurisdiction as “Lizenzgebühr, Honorar, Tantiemen, Abgabe” etc.) and the consideration of existing case law in the resolution of licensing conflicts (i.e Versata v. Ameriprise).
To tackle this, legal experts from inside and outside the DALICC consortium will check the legal validity of machine-readable licenses and the output of the reasoning engine for compatibility with applicable laws. In several iteration cycles the DALICC output will be tested against laws and jurisdictions, checked for its semantic precision deriving from various languages and adjusted accordingly.
Problem 5: DALICC User-Interface and Interaction Design
Licenses in general and rights clearance in particular are complex topics that require a high level of problem awareness and legal expertise. Due to the abstractness and complexity of the topic especially non-legal professionals have to invest a lot of time and/or money to acquire this knowledge and search for viable solutions.
DALICC will test and provide easy-to-use user interfaces that help non-legal professionals to quickly learn about the issues of data licensing and understand the consequences of unsolved licensing conflicts of their application. Thus, DALICC will leverage the overall awareness and expertise on licensing issues, reduce the barriers of entry for non-legal professionals, and reduce the costs of license clearance when legal experts are needed to resolve a client request. 
See also: Versata, Trilogy Software, Inc. and Trilogy Development Group v. Ameriprise, Ameriprise Financial Services, Inc. and American Enterprise Investment Services, Inc., Case No. D-1-GN-12-003588; 53rd Judicial District Court of Travis County, Texas.