Unit of analysis and unit of observation in research

One of the most important ideas in a research project is the unit of analysis. The unit of analysis is the major entity that you are analyzing in your study. For instance, any of the following could be a unit of analysis in a study:

  • individuals
  • groups
  • artifacts (books, photos, newspapers)
  • geographical units (town, census tract, state)
  • social interactions (dyadic relations, divorces, arrests)

Why is it called the ‘unit of analysis’ and not something else (like, the unit of sampling)? Because it is the analysis you do in your study that determines what the unit is. For instance, if you are comparing the children in two classrooms on achievement test scores, the unit is the individual child because you have a score for each child. On the other hand, if you are comparing the two classes on classroom climate, your unit of analysis is the group, in this case the classroom, because you only have a classroom climate score for the class as a whole and not for each individual student. For different analyses in the same study you may have different units of analysis. If you decide to base an analysis on student scores, the individual is the unit. But you might decide to compare average classroom performance. In this case, since the data that goes into the analysis is the average itself (and not the individuals’ scores) the unit of analysis is actually the group. Even though you had data at the student level, you use aggregates in the analysis. In many areas of social research these hierarchies of analysis units have become particularly important and have spawned a whole area of statistical analysis sometimes referred to as hierarchical modeling. This is true in education, for instance, where we often compare classroom performance but collected achievement data at the individual student level.

In statistics, a unit of observation is the unit described by the data that one analyzes. A study may treat groups as a unit of observation with a country as the unit of analysis, drawing conclusions on group characteristics from data collected at the national level. For example, in a study of the demand for money, the unit of observation might be chosen as the individual, with different observations (data points) for a given point in time differing as to which 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.

Unit of observation vs unit of analysis[edit]

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]

Data point[edit]

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.

Types of data[edit]

The measurements contained in a unit of observation are formally typed, where here type is used in a way compatible with datatype in computing; so that the type of measurement can specify whether the measurement results in a Boolean value from {yes, no}, an integer or real number, the identity of some category, or some vector or array.

The implication of point is often that the data may be plotted in a graphic display, but in many cases the data are processed numerically before that is done. In the context of statistical graphics, measured values for individuals or summary statistics for different subpopulations are displayed as separate symbols within a display; since such symbols can differ by shape, size and colour, a single data point within a display can convey multiple aspects of the set of measurements for an individual or subpopulation.

See also[edit]

  • Data
  • Data collection system
  • Observation error
  • Sample point

References[edit]

  1. ^ Blalock, Hubert M., Jr. (1972). Social Statistics. New York: McGraw–Hill. ISBN 0-07-005751-6.

What is the unit of analysis in research?

A unit of analysis is the main subject or entity whom the researcher intends to comment on in the study. It is mainly determined by the research question. Simply put, the unit of analysis is basically the 'who' or what' that the researcher is interested in analyzing.

What's the difference between observation and analysis?

The analysis is argumentative and debatable, while the observation gives evidence or reasoning to support the analysis. As you might imagine, the dividing line between what counts as an observation and what is an analysis is not clear-cut.

What are the 4 units of analysis?

Unit of Analysis: Individual, Organization, Groups, and Data Series. Units of Analysis are the objects of study within a research project. In sociology, the most common units of analysis are individuals, groups, social interactions, organizations and institutions, and social and cultural artifacts.

What is the unit of observation in statistics?

An observation unit, sometimes also called statistical unit, is the entity on which information is received and statistics are compiled in the process of collecting statistical data. An observation is the value, at a particular period, of a particular variable, such as the individual price of an item at a given outlet.