In my first two posts for Learning Circuits, I explored how I use Twitter as a professional development tool , and last week we looked at Filtering: A Challenge and Responsibility for Learning Professionals. This week we're going to explore filtering further, and explain how learning professionals will provide filtering services on an increasing basis. There are two primary ways that filtering will impact learning professionals. The first impact is in helping workers understand the need and techniques for filtering. For many, this need to filter is something they may not have considered before.