Google announced today that it has launched a new error reporting feature for the Structured Data Dashboard in Webmaster Tools. The company began testing this earlier this year, and has used feedback from webmasters to fine-tune the feature.
Users can now see items with errors in the dashboard. Items represent top-level structured data elements tagged in the HTML code. Nested items aren't counted. Google groups them by data type and orders them by number of errors.
"We’ve added a separate scale for the errors on the right side of the graph in the dashboard, so you can compare items and errors over time," notes Google webmaster trends analyst Mariya Moeva. "This can be useful to spot connections between changes you may have made on your site and markup errors that are appearing (or disappearing!)."
Google says it has also updated its data pipeline, so reporting will be more comprehensive.
When you click on a specific content type, Google will show you the markup error it found for that type. You can see all at once or filter by error type. Google suggests checking to see if the markup meets the implementation guidelines, which can be found here.
You can click on the URLs in the table to see details about what markup Google has detected when it crawled the page last and what's missing. There's also a "test live data" button so you can the markup with Google's Structured Data Testing Tool.
After you fix issues, the changes will reflected in the dashboard.