Which research technique must researchers be sure to employ to corroborate data obtained unobtrusively?

A) Science of garbology
B) Covert observations
C) Triangulation
D) Coding

Triangulation refers to the use of multiple sources or methods in research to cross-check and verify the findings. This approach can help to increase the credibility and reliability of data obtained through unobtrusive research techniques. Therefore, researchers should employ triangulation to corroborate their data. The science of garbology (A) involves analyzing people's trash to gain insights into their behavior and is not necessarily relevant to all types of research. Covert observations (B) can be unethical or illegal in certain contexts and may not be necessary for gathering unobtrusive data. Coding (D) is a valuable technique for organizing and analyzing data but does not specifically address the need for corroboration of unobtrusive data.