DEAR MISS MANNERS: I will be in a conversation with a friend, just the two of us, and she will pick up her tablet computer to search the Internet for some detail related to something one of us just said.

Then she will notice a link to something else of interest, and she never again fully rejoins the conversation. She continues to look at the computer and browse, while also continuing to approximate conversation or sometimes just narrating what she is viewing.

She is an adult, and, as Miss Manners rightly says, one must not attempt to teach manners to anyone but one’s own children. Or at least, one must not appear to do so. So how do I gracefully say, “Stop that, or I am leaving”? I don’t want to just leave without first giving her a chance to modify her behavior.

GENTLE READER: Ah, yes, a common hazard, unknown to Miss Manners’ predecessors.

The seductive part is that disputed or forgotten facts that surface in conversation can now be checked on the spot. This is a decidedly mixed blessing.

The person who was right gets to triumph immediately, rather than resorting to the dismal choice between letting it go and reviving a dead dispute. Yet instant research has a discouraging effect on conversation and an encouraging one on pedants.

Your friend has compounded the problem by veering off into the unfortunately common rudeness of snubbing an actual person in favor of playing with her own toy. You can find something else to do, if you say, “Well, I won’t disturb you. We’ll talk when you have finished your research.” It might even be best to leave before she says, “Oh, I can do both.”