In the previous piece I suggested that action research processes were good at developing understanding from experience. Theory grounded in experience. Within each action research cycle practice informs theory which in turn informs practice. It seems to me that this cyclic building block is able to offer many advantages. If you look specifically at the way it develops theory, you may well decide that it isn't all that different from experimental research.
Experiments take place in the context of the theoretical literature, which they add to or challenge.
You might say that there, too, theory informs the practice of experimentation which modifies the theory. In effect, each experiment is a cycle. One of the differences in action research is that the cycles are smaller. A given action research study contains many cycles. And they in turn may include still smaller cycles.