As automation becomes ubiquitous, it is important to know how differences in introducing automated systems will affect human-automation interactions. There are two main ways of introducing expected reliability of an automated system to users: explicitly telling operators what to expect or giving operators experience using the system. Additionally, the expected level of system reliability in an introduction can be higher-than, lower-than, or the same as the actual system reliability. This study systematically investigated the effect of introductions initially and over time on: 1) perceptions of reliability and system usage, and 2) human responses to automation (e.g., compliance, reliance, and overall dependence) for 60 undergraduates across two days. We found that explicit statements introductions had a greater effect on perceived system reliability than did initial exposure introductions, particularly initially. There were few initial differences between introduction formats on system usage. In general, system use stayed the same or increased as time using the system increased. These results can be used to inform how automated systems are introduced to users; depending on intended perceptions and uses of systems, different introductions should be considered.