Discrete trial teaching (DTT) is a common teaching methodology used within intervention for autistics/individuals diagnosed with autism spectrum disorder (ASD). Practice recommendations related to using DTT for receptive language instruction includes the desired size of the array of stimuli to be presented. Some recommendations include ensuring the size of the comparison array presented is three target stimuli. The purpose of this study was to compare the relative effectiveness of using DTT to teach three children diagnosed with ASD receptive labels with a field size of two (Fo2) or a field size of three (Fo3). The results of an adapted alternating treatments design indicated that both field sizes were effective for participants to reach the mastery criterion. The results are discussed in terms of efficiency, limitations, and possible future avenues of research.