Didactic reference is a process which denotes the spatial, temporal or functional relation between didactic discourse and its referent object. A two staged experiment was carried out. The first stage was aimed to determine the effect of two modalities of indirect reference on the acquisition of identification abilities. Twenty three college students were randomly assigned to two groups, one with eleven subjects and the other with twelve. Group 1 received textual information (discourse) before a related image (the referent object), while Group 2 received the discourse after the object. The experimental effects were observed in two test tasks: Identification on the object and identification within textual questions. Results showed that indirect reference, no matter its modality, did not contribute effectively to the development of identification on the object abilities, but it did so to the development of identification within textual questions abilities, which as a matter of fact do not require the presence of the referent object for its acquisition. The second stage was carried out immediately after the first one. Its purpose was to establish the effects of direct reference on the same identification tasks. All subjects of the first stage were assigned to a single group, and received the simultaneous presentation of the same discourse and referent object used in the first stage. Results indicated that both identification abilities significantly improved under conditions of direct didactic reference.El fenómeno de equivalencia se ha explicado tradicionalmente a partir de perspectivas operantes. El presente estudio sugiere que la emergencia de clases de equivalencia ocurre a partir de procesos de condicionamiento clásico únicamente y que el refuerzo no constituye una condición de necesidad para la adquisición de respuestas relacionales derivadas. Se entrenaron estudiantes universitarios en las relaciones A-B y A-C utilizando dos tipos de entrenamiento en ausencia de refuerzo; el entrenamiento Tipo-Respondiente y un entrenamiento de igualación a la muestra sin retroalimentación. Los resultados muestran emergencia de relaciones derivadas para ambos grupos con un desempeño un poco más alto para el grupo entrenado con el procedimiento de igualación a la muestra respondiente. Los hallazgos se discuten en términos de las interpretaciones teóricas del proceso de transferencia de funciones y de sus implicaciones en el estudio del comportamiento de los organismos.