Are there data-preparation capabilities in Watson Knowledge Catalog?

Yes. Data-preparation capabilities are available through Data Refinery, which is part of Watson Knowledge Catalog. Data Refinery provides a rich set of capabilities that not only allow you to discover, cleanse, and transform your data with built-in operations, but it also comes with powerful profiling and visualization tools, such as charts, graphs and stats to help you interact with and understand your data. Data-access-and-transform policies defined in Watson Knowledge Catalog are also enforced in Data Refinery to ensure that sensitive data that originated from governed catalogs remains protected.