In earlier work the second author introduced the tool of pointwise directed families of characteristic functions to establish that certain continuous function spaces [X → Q] were continuous domains. In this paper we extend those earlier results, while significantly simplifying and refining the machinery involved. Our main result asserts that the function space [X → Q] is a continuous dcpo if X is locally compact and coherent and Q is a retract of a bifinite domain (RB-domain) with ⊥.