Precision in architecture : certainty ambiguity and deviation A precisely ambiguous wall In praise of deviation and control : the mortar joints of the Church of St Peter Defining precision and ambiguity Disputing precision An emerging desire for precision A precise specification for an Iron Museum Anticipating precision at the Museum of Childhood A meeting between Mies and OMA The precise control of deviation at the Commons A precisely crude ceiling at the MTCC Productive deviations from certainty.