What instruction is given to string players to bounce the bow on the strings?

The instruction given to string players to bounce the bow on the strings is known as "Col Legno." This technique involves using the wooden part of the bow to strike or bounce against the strings, producing a unique percussive sound. This creates an effect that is distinct from traditional bowing techniques, where the hair of the bow is drawn across the strings.

In contrast, pizzicato refers to plucking the strings with the fingers instead of using the bow, which does not match the described technique. Legato indicates a smooth, connected style of playing where notes are played in a flowing manner without breaks, thus requiring a different approach. Staccato means playing the notes in a detached or separated manner, typically with a short, crisp articulation, which also does not correlate with the bouncing bow technique that is found in Col Legno.