The need for emotional interaction has already influenced various disciplines and industries, and online museums represent a domain where providing emotional interactions could have a significant impact. Today, online museums lack the appropriate affective and hedonic values necessary to engage art enthusiasts on an emotional level. To address this challenge, a novel system called AMARA (Affective Museum of Art Resource Agent) was developed. AMARA is a question-based search agent designed to be easy to use and sensitive to the emotional aspects of the artwork search and retrieval process. This dissertation emphasizes the affective evaluations of users interacting with an online museum system to complete given tasks. Based on Affective Response Model (Zhang, 2013), this study focused on two affective concepts; 1) system-related stimuli, which include affective quality of the system and affective cues that the system expresses to the users and 2) the relationship between a user and a stimulus. A total of 48 participants were asked to rate one of the three types of an online museum website they used in terms of pleasurable interaction, perceived aesthetics, trust, engagement, and meaningful experience (five dependent variables) after completing simple tasks of searching for artwork that they prefer. The experimental results confirmed that emotional interactions have a significant and positive impact on the online museum experience (users' perceptions of affective quality and emotions) for both untrained and trained users. Results also implied that user experience can be significantly enhanced when affective concepts are combined with cognitive values (e.g. functionality), especially in the context of trust and engagement. The outcome of this study can contribute to understanding the role emotion plays in interacting with computers and strengthen user experience design by addressing affective concepts. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]