By the late 1960s and early 1970s, planners began to look for new approaches because as happened nearly a decade before, it was realized that the current models were not necessarily sufficient. As had happened before, a number of different models emerged. Lane (2005) notes that it is most useful to think of these model as emerging from a social transformation planning tradition as opposed to a social guidance one, so the emphasis is more bottom-up in nature than it is top-down.[10]