One influential perspective on cognitive development suggests that a child's thinking abilities unfold in a series of distinct, qualitative stages, much like climbing a staircase where each step represents a new way of thinking. An alternative view, supported by much contemporary research, posits that development is a more gradual, cumulative process, like walking up a ramp. Critically evaluate the stage-based 'staircase' model. In your evaluation, discuss its potential limitations when confronted with evidence for a more gradual 'ramp-like' progression of cognitive skills.