Wiktionary
                    observability
                    
                        
                
                                                                    n. 1 (context uncountable English) The state of being observable 2 (context countable English) A measure of the extent to which something is observable
Wikipedia
                    Observability
                    
                        
                
                                                                    In control theory, observability is a measure for how well internal states of a system can be inferred by knowledge of its external outputs. The observability and controllability of a system are mathematical duals. The concept of observability was introduced by American-Hungarian engineer Rudolf E. Kalman for linear dynamic systems.
Usage examples of "observability".
How do scientists gather new knowledge when they are out at the jagged edge of observability and understanding?