Why are labels overlapping in ArcGIS Desktop?

Question

I'm not new to GIS, but just learning ArcGIS 10.

I have been led to believe that the standard labeling engine doesn't allow any overlap: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Positioning_labels_with_the_Standard_Label_Engine/00s800000020000000/

however, I am seeing significant amounts of overlap between labels in just one layer. This is the image I get:

This is within a Data Frame with a fixed scale (1:2500) and no reference scale . I wondered whether that had anything to do with it, but playing around with either of these parameters doesn't seem to have any effect. Is there anything I'm missing in the label manager options - I have checked and double checked that the "Place Overlapping Labels" check box is off. When I increase the buffer size, I get fewer labels, but some of them still overlap.

Answer 1

Ensure that the "Place overlapping labels" check mark is unchecked. This will not re-position or rotate labels but rather remove labels that overlap other labels. If you would like you can create a "static" annotation features class and export both placed and unplaced annotations. This way you can "turn-on" the overlapping labels and place them manually one by one. The default labeling engine only has basic functionality so if you need a more "intelligent" control over the dynamic placement of labels you might need to get the Maplex extension. You can also try it out for free for a limited time.

Answer 2

I guess that I would say seeing your data that I would expect arcmap to behave that way. I hadn't read the manual I guess. Saying that I would expect that the statement in the manual is still almost true with reasonable data. (your data kinda falls wihtin the exception. Long values and polygons don't mix well. Now seeing that there is another set of ticks you might try. you could set up some you could define classes of features and label feature differently (select the label all features the same) and then define display thresholds for each. becoming more restrictive as you zoom out. Several ways to restrict.

1. sql defining polygons > area
2. select the only place labels inside polygons on the placement page.
3. use several levels and set a scale range for each (i.e. 100-999, 1000 - 4999, 5000 - 199999)

Another trick you should be aware of... I often make a copy of a layer and "turn off" the symbol in the copy. then the polys and the labels can be displayed seperately. At that point you could define a definition query and only display labels for "Certain values, or types".

Trick No 2. When in the dialog (and on the webhelp page) look at the help and see options for Round(myvalue,0) or Left (myvalue, 3first three char) and many other options for display one, or more values or partial values, or calculated values. HTH