Adopter categories based on standard deviation parameters of the normal bell curve (Everett Rogers):

• Innovators: Beyond $(\bar{x} - 2\sigma) \implies 2.5\%$
• Early Adopters: Between $(\bar{x} - 2\sigma)$ and $(\bar{x} - \sigma) \implies 13.5\%$ (Correct)
• Early Majority: Between $(\bar{x} - \sigma)$ and $\bar{x} \implies 34.0\%$
• Late Majority: Between $\bar{x}$ and $(\bar{x} + \sigma) \implies 34.0\%$
• Laggards: Beyond $(\bar{x} + \sigma) \implies 16.0\%$

Stages of the Innovation-Decision Process (Everett Rogers):

• Knowledge: Becoming aware of the innovation and comprehending its function.
• Persuasion: Developing a favorable or unfavorable attitude.
• Decision: Engaging in activities leading to adoption or rejection.
• Implementation Stage (Correct): The individual puts an innovation into active practice. Rogers observes that 're-invention'—the degree to which an innovation is changed or modified by a user in the process of its adoption and implementation—occurs primarily at this operational implementation stage as users adapt the technology to local field conditions.
• Confirmation: Seeking reinforcement for the decision already made.

Everett M. Rogers defines diffusion as 'the process by which (1) an innovation is communicated through (2) certain channels (3) over time among the members of (4) a social system.'
The four main elements are: The Innovation (A), Communication Channels (B), Time, and the Social System (C).
Awareness (D) and Interest (E) are individual mental steps in the traditional 5-stage adoption model (AIETA), not macro elements of the diffusion process.