Loading article…
In statistics, a unit of observation (or individual) is the unit described by the data that one analyzes. A study may treat groups as a unit of observation withing a broader unit of analysis, for example, drawing conclusions on group characteristics from data collected over a more general level.
For example, in a study of the demand for money, the unit of observation might be chosen as the individual person, with different observations (data points) for a given instant in time differing as to which particular individual they refer to; or the unit of observation might be the country, with different observations differing only in regard to the country they refer to.
The unit of observation should not be confused with the unit of analysis. A study may have a differing unit of observation and unit of analysis: for example, in community research, the research design may collect data at the individual level of observation but the level of analysis might be at the neighborhood level, drawing conclusions on neighborhood characteristics from data collected from individuals. Together, the unit of observation and the level of analysis define the population of a research enterprise.[1]
A data point or observation is a set of one or more measurements on a single member of the unit of observation. For example, in a study of the determinants of money demand with the unit of observation being the individual, a data point might be the values of income, wealth, age of individual, and number of dependents. Statistical inference about the population would be conducted using a statistical sample consisting of various such data points.
In addition, in statistical graphics, a "data point" may be an individual item with a statistical display; such points may relate to either a single member of a population or to a summary statistic calculated for a given subpopulation.
観測単位に含まれる測定値は形式的に型付けされます。ここで型は、コンピューティングにおけるデータ型と互換性のある方法で使用されます。したがって、測定値の型は、測定結果が{はい、いいえ}のブール値、整数または実数、何らかのカテゴリの識別、または何らかのベクトルまたは配列になるかどうかを指定できます。
点という表現は、多くの場合、データがグラフ表示にプロットされることを意味しますが、多くの場合、その前にデータは数値的に処理されます。統計グラフの文脈では、個人の測定値や異なるサブグループの要約統計量は、表示内で個別のシンボルとして表示されます。これらのシンボルは形状、サイズ、色が異なるため、表示内の単一のデータポイントは、個人またはサブグループの測定値の複数の側面を伝えることができます。