How can I show points on the same coordinate as e.g. a bigger symbol in QGIS?

Question

I use QGIS 1.8 for mapping archaeological findings. Some of the findings within one layer are located on the same site and therefore have the same coordinates. Therefore you just see one point instead of the actually overlapping points. There is the tool - in German its called "Punktverdrängung" (maybe point displacement in english?), with which you can circle overlapping around a central point, but that does not really fit my needs.

Is there the possibility of showing more than one point on the same coordinates as a bigger symbol or anything like that?

Thanks for your help!

Answer 1

as stated the graduated symbols for each class. (you are not clear if these exist in the same dataset or separate).
Also if they exist in the same data set after graduating the symbology you can use the symbol levels tool to step the larger symbols under.

Found on the layer property dialog.
also in 1.8 on the style tab (1.8).

and another feature (point displacement) I have not tried at the top of the style tab.

It looks as though it uses a tolerance and radius to place point within a circle.

Feature blending may also help.
not exactly sure what it does. (qgis 1.9)

From the description in your question the term clustering comes to mind but you would use symbol clustering on a web application.
Perhaps after another read I understand.
You can also select "each" symbol in the layer properties dialog and make a separate offset for each "type" of symbol. (very manual if you have many of these). Also it applies to ALL symbols with that style (1.9).

and the same thing (1.8) on the style tab select the change button.