Which of the following is a primary concern during material sampling?

Maintaining sample integrity is crucial during material sampling because the quality and characteristics of the sample must accurately represent the material being tested. Any disturbance, contamination, or alteration of the sample can lead to erroneous test results, which could adversely affect project outcomes and decisions. When sample integrity is maintained, it ensures that the tests performed on the sample will provide reliable and valid data, which is essential for assessing soil properties and making informed engineering decisions.

While other factors like sampling size, reusability of the sample, and cost-effectiveness may have relevance in certain contexts, they do not overshadow the importance of sample integrity. A sample that is not handled properly, regardless of its size or cost, will yield results that are compromised, ultimately undermining the purpose of the testing.