Which technique should a pilot use to scan for traffic to the right and left during straight-and-level flight?

I believe the technique is Systematically focus on different segments of the sky for short intervals. Pilots must always be watchful for other aircraft. An effective scan is performed by systematically focusing on different segments of the sky for short intervals normally 1 or 2 seconds per segment. First look in the direction of the turn, raising or lowering the glider's wing to view above and below.