Currently, there is no way to respond to an idea submitter privately via comments as an administrator. Additionally, it would be helpful if this private comment could trigger a notification to the submitter.
A new option for idea visibility may help with this use case. Set the idea to 'Visible to creator'. With this setting only the submitter can see their idea in the portal and they will receive email notifications for your comments. Learn more.
I agree with previous comments the admin suggestion to reduce visibility on the idea as proxy is inadequate as in general we want to keep the idea public but engage in a private dialogue with the creator.
I'd also go as far as saying this is bad practice as the idea visibility operation is then easily reversed down the line potentially exposing comments that were private in nature.
Per the comment extending the scope of this idea to include a private response to a commenter in addition to the idea submitter - Personally, I think if the act of being able to privately engage with all portal users interacting with an idea (ie. submitter, commenter etc.) was the solution here that would be very desirable.
I concur with you Karie Kelly, but I would slightly extend that.
Ideas should be visibile to all users who have access to the portal, and they still need to be able to vote and comment on that idea.
but for comments on an idea there should be a way, in "both" directions, to exchange information "privately"
Product Manager should be able to send a "private" comment to the "idea submitter"
Product Manager should be able to send a "private" comment to a "comment submitter"
Any user who can add a comment, should be able to send a "private" comment to the "Product Manager"
Logically, this would have to be solved with a "flag" for choosing between "public and private", when posting a comment.
I appreciate the suggestion; however, that doesn't address the use case.
When you set the idea itself to Visible to Creator, as you indicate, the entire idea is only visible to the creator which limits anyone else from seeing, commenting and voting. The only other people able to see it are aha! users. The need is to send a comment to only the idea creator as the desire is to make the idea more open - however, you may want to get more information or inform them of something that is specific for their use case.