Evaluation context and its transition is one of the hardest concepts in DAX and I would find it extremely helpful, if syntax highlighting would assist us here: Let the colour of the table name show whether the expression will be evaluated: in a row context (so the table name represents the record/current row and a scalar value will be returned, Color: purple). In a filter context (so the table name represents the (eventually filtered) table and a list of its column values is returned instead, Color: gold. Ideally, it would also indicate if a filter is active or not (or can become active once the measure is used in a pivot table). So with an empty filter, there would be no syntax highlighting. I've described this idea in my blogpost here: http://wp.me/p6lgsG-KI