Description of the Observatory architecture
- Initially, an administrator populates a URL repository with web site URLs.
- The crawler gets web site URLs from the URL repository and further populates the it with individual web page URLs. The crawler extracts at most 6000 pages from each site.
- When the crawler is finished, the sampler selects 600 web pages from each site at random making a near random uniform sampling.
- Each of the 600 pages are evaluated to detect accessibility barriers by the WAM and the results are stored in an RDF database.
- The ETL extracts these results, transforms them and inserts the results for long storage in a data warehouse.
- When all scheduled sites have been crawler, evaluated and loaded in the data warehouse, the data in the data warehouse is organised to be available in the online reporting tool.
- Users can then see the results from the online reporting tool.
