An information filtering process designed to sort through large volumes of dynamically generated textual information, incrementally learning process that learns as new text documents arrive and the user grades them by providing feedback. A plurality of miss points are calculated for the vehicle and as well as object conditions at which the vehicle will miss an impact with the at least one other object by a range of miss distances. The device can be used to determine whether a particular patient is a candidate for implantation of an interspinous process spacer to treat the symptoms of lumbar spinal stenosis and the size of such a spacer if indicated.