  According to mass media theory, the dissemination of messages and the
evolution of opinions in social networks follow a two-step process. First,
opinion leaders receive the message from the message sources, and then they
transmit their opinions to normal agents. However, most opinion models only
consider the evolution of opinions within a single network, which fails to
capture the two-step process accurately. To address this limitation, we propose
a unified framework called the Two-Step Model, which analyzes the communication
process among message sources, opinion leaders, and normal agents. In this
study, we examine the steady-state opinions and stability of the Two-Step
Model. Our findings reveal that several factors, such as message distribution,
initial opinion, level of stubbornness, and preference coefficient, influence
the sample mean and variance of steady-state opinions. Notably, normal agents'
opinions tend to be influenced by opinion leaders in the two-step process. We
also conduct numerical and social experiments to validate the accuracy of the
Two-Step Model, which outperforms other models on average. Our results provide
valuable insights into the factors that shape social opinions and can guide the
development of effective strategies for opinion guidance in social networks.
