What method involves setting up quadrants and recording all items within each?

The method that involves setting up quadrants and recording all items within each is quadrat sampling. This technique is particularly useful in ecological studies and various forms of inventory analysis since it allows for a systematic way to gather data from a specific area. By dividing the study area into smaller sections or quadrants, researchers can conduct their sampling in a structured manner, ensuring that they capture a representative sample of the data within each defined area.

This approach is beneficial because it reduces bias that can occur when sampling randomly across a larger area. Instead, by ensuring each quadrant is accounted for, the analysis captures variations within the environment or dataset. It helps provide a clearer picture of the distribution and abundance of items being inventoried, making it a reliable method for gathering quantitative and qualitative data.

In contrast, systematic sampling involves selecting samples based on a fixed interval, random sampling selects items completely at random without structure, and stratified sampling divides the population into subgroups (strata) before sampling from them, but does not specifically utilize quadrants as a method for organizing the sampling process.