In the image on the left, you see a snapshot from the process of finding lead users of solar
thermal collectors. At this point in the search, there has been two starting points, Col and
Google. Google has some smaller circles next to it, which indicates not yet investigated leads.
Col is connected to other circles, which emerged on the chart as smaller circles, but were
transformed into bigger circles as the search proceeded.
The different circles are different kinds of actors (for instance, people, organisations, and
events) and the lines are different methods (snowballing, screening, broadcasting, and so on)
to get from one lead to the next.
The horizontal axis represents time from left to right in relative terms, not as an absolute
scale. The vertical axis represents the amount of sought characteristics, in this case 'lead