No research has used latency-based functional analysis (FA) outcomes as baseline data from which to evaluate the effectiveness of subsequent function-based treatments. This approach to analysis calls for the continued collection of latency-based measures for all targeted variables throughout all phases of treatment. We tracked client progress during treatment using latency-based, rate-based, and percentage-ofopportunity measures of relevant behavior and compared graphical representations of each. Visual inspection of all data indicates that changes in variability level and trend of latencybased measures correspond well with said changes in more traditional measures. et al. 1984/1992) outcomes as baseline data from which to evaluate the effectiveness of subsequent treatments (e.g., Baker et al. 2006;Lloyd et al. 2014). Practitioners with limited time could benefit from replicating this approach to analysis because of its potential to increase the efficiency of service delivery (i.e., they do not need to conduct additional baseline sessions after an FA has been completed). For similar reasons, this approach has the potential to decrease caregiver objection to essential pretreatment activities. Specifically, it allows practitioners to spend less time determining the degree to which problem behavior occurs given the presence of countertherapeutic contingencies, relevant establishing operations (EO; Laraway et al. 2003), and discriminative stimuli (S D ), potentially reducing the need to justify this difficult-tounderstand yet important practice. KeywordsAnother way that practitioners might decrease caregiver objection to important pretreatment activities is by selecting a variation of traditional FA methodology that requires fewer instances of problem behavior to establish functional relationships. For instance, latency-based FAs occasion a small fraction of the problem behavior commonly seen during traditional FAs but produce results whose interpretations closely align with those of traditional FAs (Thomason-Sassi et al. 2011).Latency-based FA data allows practitioners to say with confidence that, in the absence of treatment, specific EOs and S D s will evoke problem behavior within (for instance) 40 s of their initial presentation. Thus, if practitioners continue to track latency to first response per unit of time during treatment, then they can determine how exposure to said treatment alters these latencies across time.Generating latency-based measures of progress during treatment requires only slight changes to baseline session protocol. Whereas therapists end sessions contingent upon the first occurrence of problem behavior during latency-based FAs, therapists continue to conduct sessions for a prespecified period of time (e.g., the maximum session duration of the latency-based FA) during treatment and only end data Implications for Practitioners • Decrease probability of high rates of problem behavior during assessment • Potentially decrease caregiver objection to pretreatment activities • Increase e...