Looking at Engraving. Here's the method.
According to the Wiki, Engraving trains Agility, Creativity, Spatial Sense, and Kinesthetic Sense. Continuing with my own fort's theme of trying to create super-dwarves, I'm going to focus on agility. The following two dwarves have been selected for their differences in agility, to represent both ends of the attribute spectrum.
Ast Zasitkadol
Engraving Experience: 0
* Agility - 159
* Creativity - 1531
* S. Sense - 1345
* K. Sense - 1962
Kogan Zanegkekim
Engraving Experience: 0
* Agility - 1509
* Creativity - 1323
* S. Sense - 767
* K. Sense - 331
Each dwarf will be assigned to smooth the exterior wall of a 41x41 rock square, for a total of 168 smoothed tiles. While one dwarf works, the other will wait, with all labors turned off. No other dwarves have engraving on, and no other engraving designations or jobs exist in the fort. It may be worth noting, however, that Ast is carrying a child around.
Results:
Ast Zasitkadol
Engraving Experience: 1680
* Agility - 159 -> 177 (+ 18)
* Creativity - 1531 -> 1548 (+ 17)
* S. Sense - 1345 -> 1362 (+ 17)
* K. Sense - 1962 -> 1979 (+17)
All these gains average out to roughly +1 attribute per 10 tiles. There's no clear discrepancy in attribute gains as there is for pump operating, however.
In addition, gains likely increase quickly with skill and thus speed.
Provided I can find the time, I'm going to try and work on this some more and see if there's other professions for which large disparities exist.
Note: performing this method with Ast took 45 minutes. I skipped Kogan.