Accessibility Assessment Simulation Environment for New Applications Design and Development

ACCESSIBLE 224145, FP7-ICT-2007-2ACCESSIBLE 224145, FP7-ICT-2007-2

Accessible Web Service Accessible Web Service Assessment tool Assessment tool

Dimitrios TzovarasDimitrios Tzovaras

CERTH/ITICERTH/ITI

Accessible Web Service AssessmentAccessible Web Service AssessmentProcess OverviewProcess Overview

A Web Service Evaluation ExampleA Web Service Evaluation Example

Web Service:Web Service: A “Mapping” Web Service developed and used within the ASK-IT IP:A “Mapping” Web Service developed and used within the ASK-IT IP:

http://www-1.munimadrid.es/MappingService/wsdl/es/indra/askit/mappingws/Maphttp://www-1.munimadrid.es/MappingService/wsdl/es/indra/askit/mappingws/MappingService.wsdlpingService.wsdl

Input: Coordinates of a geographic bounding box Input: Coordinates of a geographic bounding box Output: An image showing the map of the area within the requested bounding Output: An image showing the map of the area within the requested bounding

boxbox A client application will use the service in order to get the map of a specific A client application will use the service in order to get the map of a specific

area and show it to the end userarea and show it to the end user Accessibility evaluation example:Accessibility evaluation example:

If the service provides an “alternative text” element together with the map, the client application If the service provides an “alternative text” element together with the map, the client application will be able to show an image (the map delivered from the service) together with “Alternative will be able to show an image (the map delivered from the service) together with “Alternative text”, covering the needs of the blind end users. text”, covering the needs of the blind end users.

If the service does not provide an “alternative text” element, the client application will show an If the service does not provide an “alternative text” element, the client application will show an image (the map) image (the map) not accessiblenot accessible to its blind end users to its blind end users

Web Service Evaluation workflowWeb Service Evaluation workflow

Accessible WS evaluation Accessible WS evaluation Step 1Step 1

Initially, the Initially, the evaluator inserts the evaluator inserts the URL of the Service’s URL of the Service’s WSDL file in the WSDL file in the Accessible WS Accessible WS evaluation tool and evaluation tool and asks the tool to asks the tool to “Evaluate” the WS“Evaluate” the WS

Step 1: Parsing of Step 1: Parsing of the WSDL filethe WSDL file The Accessible The Accessible

WS evaluation WS evaluation tool parses the tool parses the service WSDL file service WSDL file on the basis of the on the basis of the Axis 1 and Axis 2 Axis 1 and Axis 2 frameworksframeworks

Web Service Evaluation workflowWeb Service Evaluation workflow

Accessible WS evaluation Accessible WS evaluation Step 2Step 2

Automatic Evaluation of the Automatic Evaluation of the Service’s accessibility status based Service’s accessibility status based on information derived from step 1on information derived from step 1 A limited set of Guidelines is A limited set of Guidelines is

automatically evaluatedautomatically evaluated Guidelines which can be evaluated Guidelines which can be evaluated

automatically by only using automatically by only using information derived from the information derived from the parsing of the service’s WSDLparsing of the service’s WSDL

E.g. Guideline I4: Do not provide E.g. Guideline I4: Do not provide operations that produce no outputoperations that produce no output All this service’s operations All this service’s operations

produce output (information produce output (information contained in the WSDL file)contained in the WSDL file)

Evaluation outcome for Guideline Evaluation outcome for Guideline I3: I3: PASSPASS

Web Service Evaluation workflowWeb Service Evaluation workflow

Accessible WS evaluation Accessible WS evaluation Step 3Step 3

Alignment of the service’s operations to Accessible “Ideal Operation” Alignment of the service’s operations to Accessible “Ideal Operation” elements defined within the Accessible Ontologyelements defined within the Accessible Ontology Why?Why?

From this process, the Accessible WS evaluation tool extracts more information From this process, the Accessible WS evaluation tool extracts more information regarding the service under evaluationregarding the service under evaluation

E.g. Up to Step 2, the Accessible WS Evaluation Tool does not know what kind of content is E.g. Up to Step 2, the Accessible WS Evaluation Tool does not know what kind of content is returned from the Service upon invocationreturned from the Service upon invocation

How?How? E.g. An operation returning an image upon invocation will be aligned to the E.g. An operation returning an image upon invocation will be aligned to the

Accessible “Image Provider” Ideal OperationAccessible “Image Provider” Ideal Operation The image element returned from the service will be aligned to the image element defined The image element returned from the service will be aligned to the image element defined

within the “Image Provider” Ideal Operation’s outputswithin the “Image Provider” Ideal Operation’s outputs The “alternative text” element (if provided) returned from the service will be aligned to the Ideal The “alternative text” element (if provided) returned from the service will be aligned to the Ideal

operation’s “alt text” output elementoperation’s “alt text” output element

The Accessible WS evaluation tool now knows that the The Accessible WS evaluation tool now knows that the service provides an service provides an image as outputimage as output and whether an and whether an “alternative “alternative

text” element text” element is provided for the returned image or notis provided for the returned image or not

Accessible WS evaluation Accessible WS evaluation Step 3Step 3

Based on the ASK-IT Service Alignment Tool (SAT)Based on the ASK-IT Service Alignment Tool (SAT)

For this example, the For this example, the evaluator aligns the evaluator aligns the “hasURL” service’s output “hasURL” service’s output element to the “Image Object element to the “Image Object URL” output element of the URL” output element of the Accessible “Image Provider” Accessible “Image Provider” Ideal OperationIdeal Operation

Accessible knows that this Accessible knows that this service returns an image service returns an image upon invocationupon invocation

The Service has no “alternative text” output element that can be aligned to the “Alternative Text” output The Service has no “alternative text” output element that can be aligned to the “Alternative Text” output element of the “Image Provider” Ideal Operationelement of the “Image Provider” Ideal Operation

Only an image output element has been alignedOnly an image output element has been aligned No “Alternative Text” corresponding to the aligned image element was aligned No “Alternative Text” corresponding to the aligned image element was aligned

Web Service Evaluation workflowWeb Service Evaluation workflow

Accessible WS evaluation Accessible WS evaluation Step 4Step 4

After Step 3 (alignment) is complete, After Step 3 (alignment) is complete, further Guidelines are assessed, related further Guidelines are assessed, related to the declared type of the WS under to the declared type of the WS under evaluationevaluation

Result:Result: E.g. In this case Guideline I4.1.1 E.g. In this case Guideline I4.1.1

failsfails No “Alternative Text” element, No “Alternative Text” element,

corresponding to the aligned corresponding to the aligned “Image” output element was aligned “Image” output element was aligned for this servicefor this service

Web Service Evaluation workflowWeb Service Evaluation workflow

Finally, the evaluator should manually evaluate the rest of the Finally, the evaluator should manually evaluate the rest of the Guidelines, which were not automatically evaluated until Step 4Guidelines, which were not automatically evaluated until Step 4