The purpose of this thesis is to address one of the final outstanding questions from the basic research program into the Function Acquisition Speed Test (FAST), and to contribute to the knowledge on the FAST using the same ground-up approach taken by the developers of the method. This research investigated the utility of the FAST, a novel behaviour-analytic “implicit” test as a measure of stimulus relatedness as a function of stimulus salience. The impact of experimental setting on data quality was also explored. Following a critique of the widely used Implicit Association Test (IAT), the empirical development of the FAST method is outlined. Data for Experiment 1 (n=62) were collected remotely. An evaluative conditioning procedure attempted to establish positive and negative emotional functions for two neutral stimulus classes across three conditions, differentiated by Unconditioned Stimulus (US) salience. Explicit evaluations of the Conditioned Stimulus (CS) were recorded post-conditioning. A FAST, employing the CS and novel evaluative words, was then administered to assess the relatedness of the CSs to the positive and negative evaluative terms. The FAST proved sensitive to the conditioning contingency (i.e., performances reflected the intended evaluative associations), but did not vary as a function of the salience of the US employed during the conditioning phase. Due to unacceptably high attrition levels, Experiment 2 (n=217) replicated Experiment 1 with a larger, remunerated sample of participants. Again, the FAST proved sensitive to conditioning contingencies. An interaction between block fluency scores and CS salience was also observed. Experiment 3 (n=56) aimed to replicate these results with a smaller, supervised and non-renumerated sample. Main effects were again found, but interaction effects were not. Analysis of attrition rates across samples demonstrated that the paid, online sample in Experiment 2 produced the highest quality data, resulting in the lowest levels of attrition. Challenges, including poor data quality, low sample sizes, and methodological issues that may have compromised stimulus control are discussed in depth. These issues notwithstanding, this study provides in-principle evidence for the FASTs ability to measure the occurrence and intensity of emotional/evaluative learning experiences.