The process of selecting a tile installer for any project can be likened to navigating a labyrinth of skilled artisans. The complexity lies in the spectrum of tasks to be accomplished, which includes the choice of tile, design, the surface to be tiled, and the installation process itself. Therefore, to ensure a successful project, a series of pertinent questions must be posed to the potential installer.

The first question revolves around the installer's experience, specifically, how long they have been in the business of tile installation. It is essential to understand the historical context as the more experienced the installer, the higher their proficiency levels are likely to be. This concept is rooted in the law of practice – also known as the learning curve or power law of practice. This law stipulates that the speed of performance of a task increases with practice. Thus, the longer the installer has been in business, the faster and more efficient they are likely to be.

Secondly, it is important to inquire about the installer's area of specialization. Tile installation is a complex craft, with different areas of focus such as ceramic, porcelain, or natural stone. Each has its unique installation methods and challenges. Therefore, understanding what the installer specializes in can heavily influence the final result. This is analogous to the economic principle of specialization, where focusing on one task allows for higher proficiency and efficiency levels.

Third, a thorough understanding of the installer's certification is vital. A certified installer is likely to be well-versed in contemporary installation technologies and techniques. In addition, they would be abreast of the requisite building codes and safety regulations. This is critical as it ensures the sustainability and longevity of the project.

The fourth question to ask the installer would be their approach towards preparing the installation surface. The quality of the finished tiling job is directly proportional to the care taken in preparing the substrate. Poorly prepared surfaces can result in lippage - where the edge of one tile is higher than the adjacent - which can cause chipping or cracking over time.

The fifth query should investigate the tools and technology the installer uses. For instance, the use of a wet tile saw is crucial for precision cutting, ensuring a seamless fit and finish. Additionally, modern digital planning tools allow for accurate layouts and efficient use of materials, reducing waste.

The sixth question should center around the installer's proposed timeline for the project. While the Pareto Principle, or the 80/20 rule, might suggest that 80% of the project could be completed in 20% of the time, it is important to note that the final 20% often requires the majority of the time for the perfect finish.

The seventh query should address the warranty offered on the installation. This serves as a form of insurance against workmanship defects, providing a level of assurance to the homeowner.

The eighth question should inquire about previous clients or references. Understanding the installer's track record provides insights into their reliability and quality of work. This is similar to the statistical concept of regression towards the mean, which implies that exceptional performance is likely to be followed by ordinary performance.

Lastly, inquiring about the cost is paramount. A clear understanding of the pricing structure, whether it's a flat rate or hourly rate, can help avoid financial disputes in the future. Exploring if the cost includes the provision of materials or just labor, helps to develop a comprehensive budget for the project.

By posing these nine critical questions to a potential tile installer, one ensures they are equipped with the relevant information to make an informed decision. Following these guidelines not only ensures a smooth installation process but also a long-lasting, aesthetically pleasing final product. The fundamental guideline here is to be thorough and not shy away from asking questions. After all, the success of any project lies in the details and the timeless wisdom of "measure twice, cut once" is as relevant in tile installation as it is in any other industry.