In reply to Yun Niu.

Hi Yun - I'm not sure I understand what you mean by 'using latitude and longitude'. When using the pre-defined Geo types as described in this post, the lat/long lookups are handled behind the scenes by VA. If you are using Custom Coordinates, then there should be additional drop down lists that appear where you will need to select the columns of your data that contain the lat and long values (see my post on custom coordinates here). The background map should appear automatically when you drag the Geography variable to the report canvas. VA's auto-chart feature will recognize its Classification as being 'Geography' and automatically display an OpenStreetMap background by default. You can then change the map type to one available from Esri's arcgisonline in the Map Service drop down located in the Options panel on the right side of VA.

A Bubble map is displayed by default for point data. You can change this to a Coordinate map to display 'dots' instead of 'bubbles'. This should give you what you are looking for. To do this, go to the Options pane on the right of VA and look for the 'Map type' drop down list. Change this to Coordinates.

Hope this helps! Please reach out again if you still have questions.