阅读下列英文材料写出研究的基本问题、研究思路、结论以及研究意义。

Title： Perceived Supervisor Support： Contributions to Perceived Organizational Support and Employee Retention

Author： Robert Eisenberger， Florence Stinglhamber and Christian Vandenberghe IvanL. Sucharski and Linda Rhoades.

Three studies investigated the relationships among employees’ perception of supervisor support（PSS） , perceived organizational support（POS） , and employee turnover. Study 1 found, with 314 employees drawn from a variety of organizations, that PSS was positively related to temporal change in POS, suggesting that PSS leads to POS. Study 2 established, with 300 retail sales employees, that the PSS– POS relationship increased with perceived supervisor status in the organization. Study 3 found, with 493 retail sales employees, evidence consistent with the view that POS completely mediated a negative relationship between PSS and employee turnover. These studies suggest that supervisors, to the extent that they are identified with the organization, contribute to POS and, ultimately, to job retention.

原文翻译：

题目：领导支持感对组织支持感和员工留任的贡献

摘要：三个研究调查员工的领导支持感（PSS），组织支持感（POS）和员工流失三者之间的关系。

实验一：从各种各样的公司里找到314名员工表明，领导支持感有效地导致了组织支持感的短暂变化，这说明是员工的主管支持感促进了组织支持感。

实验二：基于300名零售员工的研究表明领导支持感和组织支持感之间的关系加强了在公司里的主管形象感。

实验三：找到493名零售员工，证据支持组织支持感有效调解了领导支持感和员工流失这一观点。这三个研究表明领导认同公司，有利于员工形成组织支持感，并最终使他们得以留任。