For other meanings see A cohort was a sub-division of the Roman infantry, originally of a Roman legion, consisting of 480 men, itself divided in 6 centurias commanded each by a centurion. In the Imperial Roman auxiliary forces, there were individual cohorts of 500 (quingenaria), and 1000 (miliaria), as well as mixed infantry... cohort

In For Wikipedia statistics, see m:Statistics Statistics is the science and practice of developing human knowledge through the use of empirical data expressed in quantitative form. It is based on statistical theory which is a branch of applied mathematics. Within statistical theory, randomness and uncertainty are modelled by probability theory... statistics and Demography is the study of human population dynamics. It encompasses the study of the size, structure and distribution of populations, and how populations change over time due to births, deaths, migration and ageing. Demographic analysis can relate to whole societies or to groups defined by criteria such as education, nationality... demography, a cohort is a group of subjects — most often humans from a given population — defined by a condition on their date of birth. For example, Canada is the second largest and the northern-most country in the world, occupying most of the North American land mass. It is a decentralized federation of ten provinces and three territories, governed as a parliamentary constitutional monarchy. It was initially constituted through the British North America Act of 1867... Canadian women born in the year 1950 would form a cohort, when studied from a point of view such as their health or This page deals with the cessation of life. For other meanings of death, see death (disambiguation). Death is a term that can refer to either the termination of life in a living system, or the state of that organism after that event. A common perception of death is a grim... mortality, or education, or Marriage is a relationship that plays a key role in the definition of many families. Precise definitions vary historically and between and within cultures, but it has been an important concept as a socially sanctioned bond between people who (usually) are in a sexual relationship. Globally, societies that sanction polygyny... marriages. Studies of cohorts often track them over extended periods of time, and return to the same sample groups decades later.