The hospitality industry, particularly the restaurant sector, is a fast-paced environment with its own set of unique challenges. Among these, payroll processing often stands out as a particularly draining task, owing to its complexity and the sheer amount of time and resources it requires. The idea of outsourcing this task to professional payroll service providers is not new, but selecting one that best suits your restaurant's needs requires a thorough understanding and strategic questioning.

The first point of consideration is the scope of services provided by the payroll service provider. Does it cover the spectrum, ranging from a basic payroll structure to intricate areas such as tax filing, benefits administration, and employee self-service? A comprehensive service saves the restaurant the hassle of dealing with multiple vendors and ensures that all payroll-related tasks are under one umbrella.

From a technological perspective, it's crucial to enquire about the software platforms used by the payroll service providers. Is the platform robust, user-friendly, and cloud-based? Does it incorporate the latest advancements in artificial intelligence and machine learning for error detection and data analytics? The answers to these questions help ascertain the technical prowess of the service provider and their commitment to staying abreast with technology's rapid strides.

The concept of 'integration' is also of utmost importance. In the restaurant business, where multiple systems like Point of Sale (POS), inventory management, and Human Resource Information System (HRIS) are in play, the ability of the payroll system to seamlessly integrate with these existing systems ensures smooth data flow and reduces redundancy of tasks.

On a more legalistic note, it's pivotal to discuss the compliance support offered by the payroll service provider. With ever-changing laws and regulations concerning wages, overtime, tip credits, and taxes, non-compliance can result in hefty fines and penalties. Hence, the payroll service provider must ensure adherence to all relevant federal, state, and local laws and standards.

The question of cost cannot be circumvented. While it's critical to have a detailed outline of all costs and fees upfront to avoid any hidden charges, it's also important to consider the cost-benefit analysis. The cost of outsourcing should be juxtaposed with the time, effort, and resources saved by the restaurant that can be redirected to its core functions.

The realm of payroll services is not devoid of the stochasticity that characterizes various other business aspects. Hence, the payroll service provider's contingency planning merits scrutiny. What are their back-up plans in case of technological failure or natural disasters? The ability to meet payroll deadlines in such adverse scenarios is a mark of their reliability and robustness.

Finally, from the viewpoint of social psychology, employee satisfaction is directly linked to the accuracy and timeliness of payroll processing. Therefore, the payroll service provider's track record in these areas is a crucial determining factor.

In essence, choosing a payroll service provider for a restaurant is a multifaceted decision which necessitates a holistic approach and a meticulous investigation. It's an amalgamation of technology, legal compliance, financial efficacy, and social responsibility. It's not just about making numbers align, but also about shaping an environment that fosters productivity, efficiency, and satisfaction.