This variation requires you to play some notes on the string and some off the string.
Where Ševčík indicates a Thrown stroke followed by a comma, the bow stroke leaves the string at the end of the stroke and the A short quick action that requires a clear connection and then leaving of the string so that the note will ring on after the bow leaves the string. stroke is best used.
To develop the collé we practice with the bow starting on the string and then starting from the air (above the string). To begin with, practice this variation slowly, finishing each collé stroke with the bow back on the string so that each new note starts from the string at the same place. In tempo however (quarter note = 138) there is not enough time to have the bow land on the string, settle and leave again so we need to start each collé stroke from the air.
Notice Ševčík’s bow placement directions in bar 4 (and similar places). These directions mean that as the bow lifts the arm also needs to move the bow from the middle to the The end of the bow that houses the screw mechanism, where the hand holds the bow. (Also 'Heel' or 'Nut'), meaning the one collé action (hand and finger action) lifts the bow into the air and the arm moves the bow from the middle to the frog of the bow.
Remember to use the flat of the finger for fifths and observe Ševčík’s dynamic markings.