In order to preserve individualism of the species (if a species is found but still undeveloped) contact would need to be made in such a way that it does not affect the culture of that species other than allowing for scientific discovery at an accelerated rate. Where the contact is made and impounded upon using the already existing aspects of that culture. Where there is no seepage between the already advanced (teacher) culture/species and the underdeveloped.
This is true only if you do not wish to affect the culture. Some species may prove to not care. It is likely that most will not be willing to show their interactions until we are at an equal and free state; or on the verge of such an event. Some interactions may be used strictly as a reminder of presence.
This is where the unknown variable or presence indicates that there is an absence of culture seepage and serves only as a reminder that you are not alone. You would not need to allow each individual to draw their own conclusions in order for this to remain true. All that the “hidden” or non interactive form of contact represents is the fact that there are other beings present in the universe.