Often called quartz topaz, citrine topaz, or topaz, all of which are misleading. It is yellow, amber, to amber brown. While a pleasing stone in terms of colour, and fairly durable, citrine is slightly softer and has less brilliance than precious topaz.
In this respect, a cohort study is often interchangeable with the term naturalistic observation. There are two main sub-types of cohort study, the retrospective and the prospective cohort study. The major difference between the two is that the retrospective looks at phenomena that have already happened, whilst the prospective type starts from the present. . The retrospective case study is historical in nature.
Observational research (or field research) is a type of correlational (i.e., non-experimental) research in which a researcher observes ongoing behavior.There are a variety of types of observational research, each of which has both strengths and weaknesses.These types are organized below by the extent to which an experimenter intrudes upon or controls the environment. Observational research is particularly prevalent in the social sciences and in marketing.here are a variety of types of observational research, each of which has both strengths and weaknesses. These types are organized below by the extent to which an experimenter intrudes upon or controls the environment. Observational research is particularly prevalent in the social sciences and in marketing.