An extens on of Carnap's λ-system of inductive logic is developed, based on a parameter measuring the variety of instances of hypotheses, θ. New axioms of inductive probability are stated, leading to the λ-θ-system. Based on this system, the notion of the information of an experiment is defined. An epistemic rule of experimentation is considered but rejected, giving way to a rule based on both information and the (non-informational) value of an experiment.