Field investigations are not characterized by randomized and manipulated control group experiments; however, most school science and high-stakes tests recognize only this paradigm of investigation. Scientists in astronomy, genetics, field biology, oceanography, geology, and meteorology routinely select naturally occurring events and conditions and look for descriptive, correlative, or causal trends. Field investigations contribute to scientific knowledge by describing natural systems, noting differences in habitats, and identifying environmental trends and issues; they are designed to answer an investigative question through the systematic collection of evidence and the communication of results. This paper describes the range of field investigations conducted by scientists and K-12 students and elaborates a comparative model of three different types of field investigations (descriptive studies, comparative studies, correlative studies). These forms of investigation are more representative of current scientific practice and provide rigorous and engaging inquiry experiences for young learners. (Contains 2 tables.)