If you focus on some of these additional aspects, do you see improvement in your ROCC profiles and group data?
Maybe one of these areas is the most important factor to consider and provide targeted intervention. If you are focusing on the overall accessibility of your site – do you see collateral improvement in the communication skills of your participants. Which areas are being impacted the most?
Maybe if you implement some strategies to improve confidence for an individual, their overall communicative competence will improve as a result of increased opportunities and practice.
Consider if the participant has limited social networks, then they may not see a need to communicate about a wider range of topics because everyone they spend time with knows them really well.
A focus on expanding their social networks and/or peer interaction, may increase their complexity of language, their range of functions and even other areas like intelligibility or seeing the system as their voice.
If you are planning to implement a peer training program, consider scoring the ROCC first, and then after a period of time to see if you are making change not only in what the peers are doing, but also in the communicative competence of the student with communication challenges.
One of the most motivating situations for a student to explore and learn to use their communication system is to interact with their friends and be part of their social circle.
The most important thing is to start the conversation. Try some things and watch to see the impact of your strategies. The ROCC can help you to measure some of those smaller increments.