The book presents an in-depth exploration of the Individuality Assisted Estimation (IAE) model in the context of Quality of Experience (QoE) assessment for multimedia, specifically audiovisual communication. The book delves into how individual characteristics, including psychological traits and states, influence perceptions of multimedia quality. The book argues for the integration of individual differences into these assessments, hypothesizing that this approach can enhance the accuracy and relevance of QoE ratings. Through a series of experiments and analyses, the book rigorously evaluates the effectiveness of the IAE model, comparing it against traditional methods, and highlights its particular strengths in estimating task load. The research contributes to the field by emphasizing the importance of individuality in multimedia quality assessment and offering a practical, empirically validated approach for incorporating individual differences into QoE models.