A third was the problem of site variation, which in the mid-1970's was identified in quantitative studies as an ill-understood source of greater differences in a program's outcomes than the program itself.
Site variation was a problem identified in the mid-1970's.
Quantitative studies have found site variation to not be concerning.
A girl kneeling in the sand throws a scoop of sand with her shovel, near her Minny Mouse bucket.
Two men race around the track.
A man performs a stunt with his skateboard.
Were you born and raised in Plano?
It must have been an Indian.
Kali is forbidden to be pictured riding animals on doors.