Constructing relational sentences: Establishing arbitrarily applicable comparative relations with the relational completion procedure

The present study examined the effectiveness of the Relational Completion Procedure (RCP) in establishing arbitrarily applicable comparative relations after training with either linear (Experiment 1) or non-linear (Experiment 2) arbitrary relations. Linear relations were those presented in a sequential order (i.e., A-B, B-C, C-D, etc.), while nonlinear relations were presented in a nonsequential order (i.e., C-D, B-C, A-B, etc.). After nonarbitrary relational training and testing to establish the contextual functions of MORE THAN and LESS THAN, adults underwent constructed-response nonarbitrary relational training and testing with physically dissimilar stimuli in which they were required to "complete" relational sentences in the presence of the cues. Next, during arbitrary relational training with abstract stimuli, participants were randomly assigned to 1 of 3 training groups: All-More (E > D, D > C, C > B, and B > A), All-Less (A < B, B < C, C < D, and D < E), and Less-More (A < B, B < C, D > C, and E > D). Finally, during arbitrary relational testing, probes for mutually entailed relations were followed by probes for 1- and 2-node combinatorially entailed relations. The yield, or percentage of participants passing, was 83% in Experiment 1 and 91.6% in Experiment 2. Our findings demonstrate that the RCP was successful in establishing arbitrarily applicable comparative relations with adults regardless of the order in which the arbitrary relational training trials were presented.