You know about statistical methodologies and data analysis techniques.
You understand the theoretical basis for applied practices. You are beginning to be able to apply the theory to practical examples. (Relevant skill level: awareness)
You know how and when to practically apply existing best-practice solutions. (Relevant skill level: working)
You understand and can apply a range of practices. You can develop deeper expertise in a narrower range of specialisms. You can start to apply emerging theory to practical situations. (Relevant skill level: practitioner)
You understand, teach and supervise a wide range of practices, or may have deep expertise on a narrower range of specialisms. You can apply emerging theory to practical situations. (Relevant skill level: expert)