A method and apparatus for planarizing a microelectronic substrate. An example apparatus includes a plurality of memory units. To overcome the large size and sparseness of the click-through data, the search system when presented with an input triplet comprising a user, a query, and a document determines a probability that the user will find the input document important by smoothing the click-through triplets. In this way, if the operator attempts to oversteer or outrun the steered wheel by rapid rotation of the tiller, a force proportional to the operator’s action is applied to oppose that action. The system also predicts health risks of diabetes, heart disease, and stroke associated with the user’s pre-regimen and post-regimen conditions.