The BBC has a rich collection of learning resources. The Knowledge and Learning website Beta aims to unlock the learning potential of this content for its users. To this purpose, the system employs semantic web technologies to organise the available learning resources. In this paper we describe the core data model that underlies the Knowledge and Learning website Beta1. The Curriculum Ontology formally describes the UK national curricula to allow users to easily discover content. We explain how the curriculum ontology supports the BBC Knowledge and Learning Beta website and discuss the challenges and bene ts that such an architecture provides.
Online learning resources have the potential to support a wide range of users.
Each learner is an individual, with his or her own motivation for studying,
accessing resources, and study habits and practices [
The BBC has understood the value of online learning from the early stages of the web, and has provided rich educational material to those wanting to learn. An example of this is the BBC Bitesize website2, which started back in 1998 and is a popular formal education resource.
In the formal learning space the BBC has a number of sites: the already mentioned Bitesize, Skillswise3 and Class Clips4 amongst others. There are tens of thousands of content items across these sites, with each site having di erent mechanisms for publishing, discovering and describing the content it serves.
To provide a coherent learning experience to users, a model for describing content in the context of the UK national curricula was developed. This model provided the foundation for building the new Knowledge & Learning beta website, presenting learning resources in the context of the UK national curricula in a consistent way. In addition, it allows for consistent re ection of changes in the national curricula throughout the product.
Designing the architecture of such a system is a challenging task. Each of the existing sites have similar yet di erent ways of describing and navigating through their content. In addition, the existing learning sites do not have a single content description model that could be reused in the beta site. Having a exible structure in the backend that can re ect the national curriculum and that can be used for consistently describing and organising learning resources is a key feature of the architecture.
In this paper, we present the architecture behind the Knowledge & Learning Beta site and we focus on the curriculum ontology, which is central to the architecture. We show how it is used to describe and organise learning resources, how it supports navigation and how it is aligned with semantic markup vocabularies for Search Engine Optimisation (SEO). We will also present some of the challenges we faced and discuss future work. 2
The Knowledge & Learning Beta website aims to bring together the variety of BBC factual and learning content into a coherent model. At the time of writing, the education pages serve two types of learning content; (1) Video Clips and (2) Revision Guides.
Video Clips Figure 1 shows an example video clip from the education pages. Video clips are related to a learning topic and are accompanied by classroom notes, which are notes on how a clip can be used in the classroom. The users for these clips are mainly teachers. The material provided in these pages aims to educate as well as stimulate the mind around topics in genres like history, science, arts. A video clip can be suitable for many topics of study, however, the classroom notes add value by providing information on the context of a programme of study. For example, the video clip of Figure 1 is also featured in other topics of study like Energy and Atoms and radiation. However, the classroom notes can be di erent as the clip is presented in a di erent context. Revision Guides Revision Guides are a rich interactive content format consisting of revision chapters, tests and activities. An example revision guide is shown in Figure 2.
Revision Guides have a di erent learning purpose from video clips. They provide learning material in a stepwise way so that the learner moves from broader to more speci c knowledge on a topic. Revision chapters provide an overview of educational material for a particular topic of study. Activities provide interactive material such as videos, games etc. The tests have multiple choice questions based on the revision chapters.
Both video clips and revision guides are structured based on the UK National Curricula. In the next section, we present the back-end architecture of this system.
The Knowledge & Learning uses a Dynamic Semantic Publishing (DSP)
model in its architecture [
In a nutshell, the ontology and its instance data are served by the Linked Data Platform, which amongst other services it provides the BBC internal triple store. Learning content such as video clips and revision guides are saved as XML Documents in a di erent system named as Content Store. The Content Store serves all the educational resources that are shown in the online pages and it is also the main system used by the editorial team for authoring new content. The coupling between Learning resources and curriculum ontology is done through semantic annotation. In particular, the content items are tagged with curriculum instances so that the Application Layer can retrieve related content for curriculum ontology instances. The de nition of new curriculum instances and the tagging procedure is part of the work ow for publishing content. Our editorial teams initially de ne the vocabulary ( elds of study, topics of study etc) that is used for annotating educational content. Then video clips and revision guides are tagged with the corresponding topic of study. In this way the Application Layer can retrieve the corresponding topics of study and their associated content and render this information in the online pages.
In the following sections, we will focus on the curriculum ontology and show the bene ts of linked data for supporting online learning resources. One main bene t is that using linked data in the backend can o er exibility on the aggregations of content. In addition we will present how the ontology is mapped with learning markup vocabularies and how linked data are used e ectively with markup for improving search. 4
The Curriculum Ontology is a core data model for formally describing the National Curricula across the UK. The full documentation as well as the latest version of the ontology are available online5. The instance data of the curriculum ontology are published on GitHub6.
The Curriculum Ontology aims to: { provide a model of the national curricula across the UK { organise learning resources, e.g. video clips and revision guides { allow users to discover content via the national curricula
The Curriculum Ontology has been designed to organise content in a way that allows students and teachers to navigate and discover learning resources. It achieves this by providing broad units of learning (e.g. a Topic) and more nely grained units (e.g. a Topic of Study). Figure 4 depicts the classes and properties in the curriculum ontology. 4.1
The core concepts in the ontology are (1) Level, (2) Field of study, (3) Programme of Study, (4) Topic of Study and (5) Topic. In the ontology, these con
cepts are represented as OWL Classes [
Level and its sub-concepts Level refers to di erent stages of education. Typically, there are four di erent ways to specify the levels: Age Range, Year, Key Stage and Phase. Thus, in the ontology these concepts are modeled as subclasses of Level.
Key Stage is a way to specify the stage of the state education system in England, Wales, Northern Ireland. Some example Key Stages are KS3, GCSE etc. Year is a way to specify the stages of education.
The Phase sub-concept is borrowed from the controlled terms for describing phase of education, which are published by the data.gov.uk7. The phases of education include Primary, Secondary and 16-Plus.
Fields of Study It refers to the discipline of a curriculum. Some example elds of study are Science, Maths, English Literature etc.
Programmes of Study A programme of study is the combination of a nation, an educational level and the subject (Field of Study) being studied. Thus, in the ontology, the Field of Study class is connected to the Field of Study with the taughtInField predicate and to the Level with the taughtAtLevel predicate. Some example programmes of study are `GCSE Maths', `Higher Biology' etc. Topics of Study A Topic of study is a topic within the context of a programme of study. It aims to provide a formal learning context to an asset or a collection of assets. An example topic of study is `Circuits', which is taught in the `KS2 Science' programme of study.
Ordering Topics of Study The ordering of Topics of Study is a key
requirement in the Curriculum Ontology, because some Topics of Study can be
prerequisites of others. For instance, students have to learn the English alphabet
before English grammar. The TopicOfStudyList class uses the external Ordered
List Ontology [
Topics A Topic can highlight the content of the learning resources in a more speci c way than the Field of Study. For example, energy is a topic of physics. Topics of Study viewed as Topics In the curriculum ontology, the di erence between a Topic of study and a topic is that mapping content to a Topic of Study makes it easy to nd speci c content whilst mapping to a generic Topic allows users to discover a wider range of content.
A Topic of Study is de ned as a Topic in the context of Programme of Study. It addresses the following issues: { A Topic across Levels. The meaning of a Topic, e.g. `Geometry (Shape & Space)', can vary for di erent Levels. Geometry for KS1, usually called `Shape & Space', needs a di erent description to Geometry in KS3 as KS1 is typically for primary-age students whereas KS3 is for secondary-age students. { A Topic across Fields of Study. For example, `Energy Resources' is a Topic of both Physics and Geography, but the learning content for `energy resources for physics' and `energy resources for geography' can be di erent. { Topic synonyms. The topic of `algebra' is usually described as `relationships' in the Scottish national curricula and as `Algebra' in the English curricula.
Fields of Study viewed as Topics A Field of Study could also be viewed as just a Topic covering a broader area of learning. The reasons for de ning them as two separate concepts are: { Fields of Study are published by Government bodies. For instance, the Fields of Study taught at primary schools in England are published by the government here. In general the national curricula de ne the breadth of a eld of study but do not provide a prescriptive list of individual topics, although in some levels (e.g. GCSE) exam boards do specify a list of Topics of Study for each Field of Study. { Usage of topics across di erent Fields of Study. As mentioned previously, some Topics can be used across Fields of Study. 5
E ective description and organisation of learning content is achieved by semantically annotating learning content with instance data from the Curriculum Ontology. Figure 5 shows an example instantiation of the core concepts from the curriculum ontology.
Figure 5 depicts the interlinking of two topics of study (`GCSE Physics Electricity' and `KS2 Science Circuits') that belong to di erent programmes of study, but they are around the same topic, which is `Electricity'. The `GCSE Physics' programme of study has a relationship with the corresponding Field (`Physics') and Level (`GCSE')9. The information about a topic of study holds also information about the level, programme of study and related topic. Having such a structure in the backend has multiple bene ts, such as achieving more dynamic aggregations of content and providing a meaningful organisation of the content that re ects the UK National Curricula. 5.1
The Curriculum Ontology is the glue that holds the content together and the basis of the website navigation. Following a Dynamic Semantic Publishing approach we moved away from a relational publishing model to one that separates semantics from content and allows dynamic aggregations.
Figure 6 shows an example of the use of the curriculum ontology instance data for organising content and for the provision of the main navigation in the website. In particular, it shows how the topic of study GCSE Physics Electricity and related data of Figure 5 are shown in the front end. Related information about the Level, Super eld (Science) and sibling elds (Biology, Chemistry, Physics) are presented in a hierarchical way in the navigation panel. This information is retrieved by querying the triple store through the Curriculum API. The curriculum API 9 More precisely, `GCSE' is the Phase but it is inferred to be a Level too. provides the result of the SPARQL queries in the Application API (Figure 3). In addition, the list of topics of study shown in Figure 6 is implemented with the Ordering List Ontology Design Pattern (ODP), described in Section 4.1.
The use of Linked Data in the architecture of the system can help towards a dynamic aggregation of content. Additional views can be implemented by querying a di erent part of the graph like for example, creating an aggregation view of content grouped by topic. 5.2
The Learning Resource Metadata Initiative (LRMI) [
Instead of modeling school curricula, LRMI provides a generic framework
for describing learning resources, which is independent from certain educational
frameworks. To this end, LRMI introduces the concept AlignementObject and
the educationalAlignment property [
The AlignmentObject class provides an alignmentType property that describes the type of alignment being speci ed. In Figure 7, there are two types of alignment, the `educationLevel' and the `educationalSubject'. These types allow alignment to the corresponding Curriculum Ontology classes. OWL restrictions are used to enforce that correct alignmentType properties are used. Thus, if we want to say that all instances of curric:Level are of schemorg:AlignmentType \EducationalLevel" this can be implemented in OWL as: curric : Level a rdfs : Class ; rdfs : s u b C l a s s O f _ : o w l R e s t r c t i o n A ; rdfs : s u b C l a s s O f schemorg : A l i g n m e n t O b j e c t .
schema.org/
Text schema.org/ alignmentType schema.org/ AlignmentObject educsactihoenmalaA.loigrgn/ment schema.org/ VideoObject
owl:hasValue owlRestrictionA rdfs:subClassOf owl:onProperty curric:Level rdfs:subClassOf
rdfs:subClassOf rdfs:subClassOf curric:FieldOfStudy
rdfs:subClassOf rdfs:subClassOf curricO:PfSrotugdraymme rdfs:subClassOf curric:Topic educationLevel schema.org/ alignmentType rdfs:subClassOf curric:TopicOf
Study
rdfs:subClassOf rdfs:subClassOf educationalSubject schema.org/ alignmentType owl:onProperty owlRestrictionB owl:hasValue schema.org class OWL Restriction Curriculum Ontology class Literal value
Similarly every instance of a curric:ProgrammeOfStudy, a curric:Topic, curric:FieldOfStudy, curric:TopicOfStudy can be implied to be an schemorg:AlignmentType \edcationalSubject". 5.3
In order to feed search engines with metadata about learning resources and the UK curricula, semantic markup is added to the HTML pages of a content item, i.e. a video clip. Figure 8 demonstrates an example markup using typicalAgeRange and educationalAlignment. GCSE is associated to an instance of VideoObject. The content of the alignmentType property indicates that GCSE is an educational level. Similarly, a eld of study and topic of study can be de ned as educational subjects by de ning the value of alignmentType to educationalSubject.
Google Custom Search engines10 can be easily built with the help of
semantic markup. A custom search engine built with re nement for GCSE and
KS3 (more:p:AlignmentObject-name:KS3, more:p:AlignmentObject-name:GCSE)11
is shown in Figure 9. The screenshot shows the results for GCSE and KS3 levels
when searching for `Hamlet'.
10 https://www.google.com/cse
11 https://www.google.com/cse/publicurl?cx=005635636900202455771:
bttbeggy8g0
For this work a number of online education resources and vocabularies were
researched. The UK government12 provides a very useful structure in their online
educational resources, which were considered in the curriculum ontology as well.
In particular, the notion of Educational Phase is also used in the BBC
curriculum ontology. Other ontologies like the Bolowgna ontology [
In addition, the work from [
The support of education data with Semantic Web Technologies [
Fig. 9: Google Custom Search Engine for BBC Education. 7
The BBC o ers tens of thousands of learning resources across its sites, with each site having di erent mechanisms for publishing, discovering and describing the content it serves.
To improve consistency, we incorporated ontology models and linked data in the architecture of the BBC Knowledge & Learning Beta Online Pages. In particular, the development and use of the curriculum ontology in the architecture of the system allowed for interlinking curriculum concepts allowing every content item to be semantically annotated with relevant curriculum topics. In addition, content can be discovered consistently and shown in context with other similar content. This is achieved by semantically annotating learning content with Curriculum Ontology instance data. Mapping the Curriculum Ontology concepts with learning markup vocabularies, such as the Learning Resource Metadata Initiative (LRMI), allowed for better precision in search using the metadata of the learning content.
Hiding the model's complexity and providing a consistent navigation is a challenge of the architecture, which is achieved with the implementation of services and APIs on the top of the linked data. A bene t of the ontology supporting the BBC online education pages is that it can o er dynamic aggregations of content achieved by querying the linked curriculum data. It can also help to easily discover content. For example, the recommendations on other relevant topics to a clip is done via the ontology data. Building additional recommendation services using the curriculum ontology and other ontologies is a good future work direction.
One key requirement of the new Knowledge & Learning is to provide a consistent model re ecting the UK National curricula where users can learn more about science, nature, history, religion, arts and more, in a continuous learning journey. Semantic Web Technologies and Linked Data can give a leverage in accomplishing this task as they allow an e ective interlinking and querying of web data.
Acknowledgments. The authors would like to thank Ali Craigmile, Jemma Summer eld, Paul Rissen, Amaal Mohamed and Zoe Rose for their help on the design of the BBC Curriculum Ontology.