Understanding Metadata
Meta data is data about other data—the metadata describes the other data. This is important because providing metadata along with your work transforms your data into usable information. Metadata adds value by providing others with the context necessary to discover and correctly interpret, understand, and use your work products. Therefore, metadata is fundamental to effectively sharing GIS information. Metadata lets other users know who, when and how data was created. It can be used to share a history of geoprocessing operations applied to create the data. It can be used to enhance traceability and version management and ensure that users know which version of information they are viewing and whether it is the most up-to-date revision available. Thus, metadata can promote more effective collaboration between teams both inside and outside your organization.
The Value of Metadata
The value of adopting a metadata standard is that everyone knows what format and style of metadata is expected, where to find the metadata fields, and how to interpret them. This enables information to flow more easily between organizations. It also preserves the value of data, eases future interpretation, and enables data archiving for potential future use. Providing standardized metadata allows tools and websites to index content and make it searchable and discoverable by more users.
Challenges
Keeping metadata in sync across different versions and platforms is a significant challenge. I do not feel that the Esri product suite addresses this elephant in the room. Too often maintaining metadata is not a priority and is overlooked. It seems that creating effective tools to manage metadata is not a glamourous task for Esri developers and they don’t put their best people on it. I think that Esri have underestimated the challenge but maybe this does not translate into an attractive business opportunity.
The fundamental challenge is that a new copy of the metadata is created each time a new child object is added. The user can opt to copy relevant portions of the parent object’s metadata to the new child object. So, for example, a project’s metadata can be copied to a feature class, or map. This is useful since it is desirable for each object to have its own metadata so that it can stand alone. But, since the values of the metadata fields are copied into the child object rather than included as a reference to the parent’s metadata this creates many duplicate copies of the same metadata. This is inefficient but works fine until the parent’s metadata must be updated. At that point, there is no easy way to propagate the changes to all the descendants and copies. Due to this issue, workflows and tools that add metadata need to be carefully architected to ensure a logical sequence of events, a correct flow of metadata, and ensure consistency across copies and descendants. Otherwise, it can quickly become a very tedious and error prone task to find and update the many copies of the same metadata.
If you create an object with metadata in ArcGIS Pro and then update the metadata in ArcGIS Online the changes are not propagated back to the geodatabase used by ArcGIS Pro. The correct way to handle this situation and ensure the metadata remains consistent and synchronized on all platforms is to make the update to the object’s metadata in ArcGIS Pro and then upload that object, for example a map or feature class layer, to ArcGIS Online again. This will overwrite the metadata stored in ArcGIS Online with the updated version from ArcGIS Pro. However, if you have the budget, there is a better way to handle this situation – you can purchase and implement the ArcGIS Enterprise Portal product. With Enterprise Portal a single up-to-date copy of the metadata can be stored in a shared database and referenced by both ArcGIS Pro and ArcGIS Online.
Conclusion
In summary, metadata matters because it adds value to geospatial data and transforms it into useful information and provides the context which allows that information to be meaningfully shared with others across space and time.