average horizontal distance between subject and target during voluntary locomotion in an experimental apparatus measurement of voluntary locomotion into, out of, or within a discrete space in a Morris water maze apparatus average horizontal distance between subject and target during voluntary locomotion in a Morris water maze apparatus 2025-06-24T17:41:17Z CMO:0004099 PMID:16837653 This is a calculation of the arithmetic mean of all measured horizontal distances between a test subject and a specific target such as a submerged platform as the subject searches for the target. Horizontal distance is the length of a line between two points within a single plane parallel to the ground. clinical_measurement_ontology slaulederkind