Final answer:
In a high-performance work system company, the practice that supports the principle of shared information is gainsharing.
Step-by-step explanation:
In a high-performance work system company, the practice that supports the principle of shared information is gainsharing. Gainsharing is a system where employees receive a portion of the company's financial performance based on predetermined goals or benchmarks. It involves open communication and sharing information about the company's performance and results, encouraging employees to work together towards common goals.