mathematical webs accessibility csun 2014

Miquel Centelles, Mireia Ribera, Inmaculada RodríguezAdaptabit Group – University of Barcelona

CSUN Conference 2014

The visionThe problemSetting the stageOur point of viewOur solution: MathML, OCR

(InftyReader) and linked dataResults and future work

March 2014 CSUN 2014 - Potential accessibility of mathematical webs 2

Teaching methodologies have shifted from content-based to skills-based learning.

A key business for teachers is the selection of web resources which serve as reference, extension and motivation to their students.

This selection is mainly based on content and source quality, but rarely considers accessibility criteria.

Accessibility criteria will be increasingly important.


Still lots of non-accessible math web sites.

Why? Interactivity. Formulae in graphics or

videos. Authoring tools automatic conversion to

MathML▪ Not fully reliable▪ Often convert to images


Concerning accessibility in maths, several initiatives have been driven by publishers and libraries.


Concerning the semantic meaning to mathematical formulae several initiatives link MathML with the semantic web. Christoph Lange: a proposal to describe

generic mathematical formulae. OpenMath: a lightweight ontology to endorse

the meaning of mathematical symbols. HELM: the pioneer in representing structures

of mathematical knowledge in RDF.


To assess the potential accessibility of non-accessible math web sites? Definition: Potential accessibility = The

feasibility of converting them into accessible webs

To publish assessment results in a semantically-empowered way


How to accessibilize a Math web? Converting to MathML

Re-writing formulae<mrow>

a ⁢ <msup>x 2</msup> + b

⁢ x + c

</mrow> Describing formulae in

alternative text“A times square x plus b times x plus c”

Converting through OCR<mrow>

a ⁢ <msup>x 2</msup> + b

⁢ x + c

</mrow>March 2014 CSUN 2014 - Potential accessibility of mathematical webs 8

OCR is the best option: Does not require expertise OK for low resources Can be done by the student


First Conceived for Web pages.

After General format for exchanging

mathematics. Now

Provides accessible content for people with disabilities.


MathML support still incomplete but…


Pros Recognizes math symbols, converts

them into ▪ LaTeX, ▪ XHTML and MathML.

Cons Strong requirements:

▪ Pure B&W▪ High resolution (600 dpi)▪ Standard ISO 80000-2:2009


The four principles of linked data publishing model:

Use URIs as names for things. Use HTTP URIs so that people can look up

those names. When someone looks up a URI, provide

useful information, using the standards (RDF, SPARQL)

Include links to other URIs. so that they can discover more things.


Opportunities for the data in accessibility reports:

To customize answers to user queries. To generate data-enriched reports for

managers, technicians (webmasters) and policy decision makers.

To enrich search engines results with accessibility results used as website quality indicators.


TWO KEY DECISIONS

Reuse a formal vocabulary: EARL

Use an open-source CMS: Drupal.


EARL = Evaluation and Report Language

It is a simple vocabulary that describes test results, such as those generated by web accessibility evaluation tools.

It uses the RDF data model to define terms for expressing test results.

It is a W3C Working Draft.


A new controlled vocabularies for the Test Case class: Containing 10 suitable criteria based on

requirements of both InftyReader OCR software and ISO 80000-2:2009

Examples:▪ C2-INFTYREADER: Image resolution must be

equals or greater than 600 dpi.▪ C3-ISO: An explicitly defined function not

depending on the context is printed in Roman (upright) type, e.g. sin, exp, ln.


A new controlled vocabularies for the Test Result class: Containing 5 categories, based on the

percentage of formulae correctly converted into MathML.

Examples:▪ Failed conversion [0%-20%]: This web has a

very low potential accessibility.▪ Successful conversion [80%-100%]: This web

has the maximum potential accessibility.


Drupal is the first CMS with Semantic Web services

▪ Use by non-experts▪ Drupal 7 publishes data in RDF format.

Data model in RDF

Data model in Drupal 7

Content type RDF class

Field RDF property

Node RDF resourceMarch 2014 CSUN 2014 - Potential accessibility of mathematical webs 22

Most websites not accessible at all Interactive Non-interactive

▪ Formula images ▪ With very poor quality▪ without alternative text.

▪ Formulae not following standards => OCR not working


Useful methodology?

Future work: Using math ontologies

▪ OpenMath▪ OMDoc

Adapt formulas to RDFa


Questions, suggestions, [email protected]

http://www.ub.edu/adaptabit/[email protected]


CSUN 2014 - Potential accessibility of mathematical webs

Specification: Analysis of data sources. URI design. Publishing license.

Vocabularies and ontologies Transform into RDFPublication Exploitation

35March 2014