# Value Changed Tag Event Data Quality **URL:** \ **Category:** General Discussion\ **Created:** [November 13, 2019, 7:49pm UTC](https://forum.inductiveautomation.com/t/value-changed-tag-event-data-quality/29922 "2019-11-13T19:49:37Z")\ **Posts on this page:** 1\ **Showing post:** 7
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [November 13, 2019, 10:18pm UTC](https://forum.inductiveautomation.com/t/value-changed-tag-event-data-quality/29922/7 "2019-11-13T22:18:54Z")
Some general advice: > [@User object functions](http://forum.inductiveautomation.com/t/user-object-functions/28211/4): > > Unfortunately, at some level (and it’s easy to do, so there’s no real way to tell you exactly when it will be) you “break out” of the expected areas where we’ve documented things and end up in the base Java classes that we’re using internally. Jython automatically wraps these up so they mostly seem like Python objects, so it’s hard to tell exactly when you get there. What I generally recommend, if you’re encountering something unfamiliar and want to see what you can do with it: Start with run… More specifically: Printing the `type` of `currentValue.quality` (literally, just `print type(currentValue.quality)` will probably give you something like `com.inductiveautomation.ignition.common.sqltags.model.types.DataQuality` - the name of the Java class in our codebase. While I'd highly recommend the introspection tools I outline in the above post, you can also just go straight to the reference material (for example: [ignition 7.9.5 API](http://files.inductiveautomation.com/sdk/javadoc/ignition79/795/index.html)) and just look for `DataQuality` there. You'll see that [this class](http://files.inductiveautomation.com/sdk/javadoc/ignition79/795/com/inductiveautomation/ignition/common/sqltags/model/types/DataQuality.html) implements the underlying [`Quality`](http://files.inductiveautomation.com/sdk/javadoc/ignition79/795/com/inductiveautomation/ignition/common/model/values/Quality.html) interface, which is where the `isGood()` method is actually defined. --- _[View the full topic](https://forum.inductiveautomation.com/t/value-changed-tag-event-data-quality/29922)._