Which of these is the best example of providing details on demand for the purpose of information visualization?
1) Placing the mouse pointer over a datapoint brings up a popup window with more information about the datapoint.
2) Progressively adding more detail to an overview visualization at the rate of one item every 10 seconds.
3) Clicking on a datapoint to remove it from the chart to make room for a label.
4) Interviewing the intended dashboard user to determine which information is important to display.