This are the three levels of decison making:
Extensive problem solving - early stages of decision making in wich the buyer has little information about brands and has not yet developed well defined and structured criteria by wich to choose among products.
Limited problem solving - this is a more advance stage, choice criteira are well defined but the buyer is still undecided about wich set of brands will best serve him. Thus the consumer still experiences uncertainty about wich brand is best.
Routinized response behaviour - buyers have well defined choice criteria and also have strong predispositions toward the brand. Little confusion exists in the consumer's mind and he is ready to purchase a particular brand with little evaluation of alternatives.
The model then borrows from learning concepts to explain brand choice behaviour over time as learning takes place and the buyer moves from exclusive to routinized problem solving behaviour. here the four major components get involved.