Name for operation value settings

[anordin95]

We need to come up with an accurate and understandable name for the values that operations use to perform execution. For instance, a greater than row operation requires a value to act as a threshold. We seek to find a good name for describing the values that these operations need. Currently, we call them hyper-parameter settings, but that's not a great word because it's already used to mean a parameter of a prior distribution.