Thanks for bringing this up, Caitlin. It's pretty obvious to those of us who've been steeped in this subject for a while that an organization can't say it's trauma-informed if it's had only a one-day training, although I've heard of some that do so.
Also, doing trauma-informed training without explaining ACEs science (epidemiology of ACEs, i.e., the ACE Study; neurobiology of toxic stress; biomedical and epigenetic consequences of toxic stress; and resilience research), tells only part of the information necessary to make the mental mind shift that so many ACEs science pioneers talk about.
For example, If ACEs science isn't included in trauma-informed classes for parents, it can set them up for failure: If they don't understand that things people often regard as "normal" parts of childhood -- losing a parent to divorce, being verbally abused, living with a family member who's an alcoholic, etc. -- may have affected their ability to have a healthy relationship with their children, the first time they're triggered by their child's behavior (i.e., the parent loses it without thinking about it and doesn't understand why), they are likely to question their ability to adopt healthy parenting skills taught to them.
All that said, Trauma Transformed in the San Francisco Bay Area, has developed a list of tools for agencies to do self-assessments.
That's one way of getting at how effective trauma-informed training is. Another is to provide a consumer guide to trauma-informed/resilience-building training. We're overhauling our resource center, and will have that guide, along with others by the Fall.
We'll also be adding an assessment tool to the Roadmap soon that addresses becoming trauma-informed in context of being part of a community initiative.