Katahnyané, sapunapi ja, wénten makudang-kudang paiketan pantaraning variabel-variabel puniki, sané ngirangin kabecikan eksperimen alami relatif ring napi sané prasida kacutetang yéning eksperimen terkontrol kamargiang.
Usually, however, there is some correlation between these variables, which reduces the reliability of natural experiments relative to what could be concluded if a controlled experiment were performed.