Parts For Works For Piano + Solo Instrument(S)

For works for a piano plus another instrument, such as a violin or cello sonata/trio, do you usually give each individual player parts, or do you give them the full score so that they can see what each player is doing?

Pianist gets the full score, soloist gets just their own part unless if it's a singer, or if it's an extremely rhythmically difficult piece, in which case it may make more sense for both players to have full scores. Also, it can't hurt to make the solo instrument into a small stave on the full score to help out the pianist.

What Robin said. What I usually do and suggest is have each player have a full score with them during rehearsals to aid in figuring out who plays what and where (this applies to ALL chamber music)

Thank you! :) That all makes sense. I would like both of your guys' posts, but an error keeps occurring. 

I think there is nothing else to add what Robin said.

For very short scores (for example, the full score is only 2 pages long) I've always had both performers play from the score and they've appreciated this. 

It would be nice for the soloist to see the piano, but practically speaking it would make it difficult for page turns. The pianist would most likely have a page turner.