Determining the quality of various materials is directly related to the quality of the final building products. Developers need to adopt a sampling and inspection approach to ascertain the quality of materials, as inspecting every single piece would be prohibitively expensive and impractical. Hence, enterprises must use sampling methods to scientifically assess materials to judge the quality of batches. 

Reasonable sampling is representative, and the key to sampling is the quantity. Materials like cement and sand cannot be fully inspected, and insufficient sampling cannot ensure the accuracy of test results. Therefore, scientific methods must be used to select a reasonable quantity of building materials for sampling inspections, ensuring the validity of the tests and saving developers on inspection costs.