 Lange goes on to suggest that in actual science the practice of constructing a hypothesis by way of accommodating known evidence has a tendency to generate arbitrary conjunctions. Thus Lorentz’s contraction hypothesis, when appended to his electrodynamics to accommodate the failure to detect optically any motion with respect to the aether, resulted in an arbitrary conjunction (since evidence that supported the contraction hypothesis did not support the electrodynamics, or vice versa)—essentially for this reason, Lange argues, it was rejected by Einstein as ad hoc. When evidence is predicted by a theory, by contrast, this is typically because the theory is not an arbitrary conjunction. The evidential significance of prediction and accommodation for Lange is that they tend to be correlated (negatively and positively) with the construction of theories that are arbitrary conjunctions. Lange’s view might thus be classed as a weak heuristic predictivism, though Lange never takes a stand on whether scientists actually rely on such correlations in assessing theories. 