What does “effective” mean in DBT?

This can seem like quite a subjective question. Who defines what effective is? From whose perspective and whose goals?  

We define “effective” as knowing how you feel and being able to meet the demands of the environment. This also means being able to experience at times intense emotion and still acting within your values. It's the ability to match the emotional demands of the current moment balanced with longer term goals that are important to you. 

The word “effective” may also be applied to the use of skills since skillful behavior can be recognized as effective by others. However, sometimes skillful means can be applied towards ineffective ends, which would be an ineffective application of effective behaviors.  An example may be DEAR MANing  someone for a request that you know is against their values.  Ineffective goals may lead to skillful behaviors being seen as manipulative by others.  

Effective is relevant to your goals, taking into account impact on important relationships. Our impact on relationships directly influences the quality of life we can experience.