Obtrusive and Unobtrusive Measurement

Definitions unobtrusive: adjective:
1. Not obtrusive; Not blatant, aggressive or arresting
2. Inconspicuous

Why use unobtrusive method ?
-. Access
-. Unique opportunity

In observation techniques, methods for gathering data by watching test subjects without interacting with them
Direct Observation: Researchers watch a behavior as it occurs and report what they see.
Indirect Observation: Researchers observe the results of a behavior.
Unobtrusive or Disguised Observation: Subject does not know he/she is being observed.
Obtrusive or Undisguised Observation: Subject knows he/she is being observed.

Six Different Ways Of Classifying Observation Methods:
1. Participant vs. Non participant observation.
2. Obtrusive vs. Unobtrusive (including physical trace observation).
3. Observation in natural vs. contrived settings.
4. Disguised vs. non-disguised observation.
5. Structured vs. unstructured observation, and
6. Direct vs. indirect observation

Social scientists distinguish between obtrusive and unobtrusive measurement. In obtrusive or reactive measurement, research subjects are aware that they are being studied. In unobtrusive measurement, the subjects are not aware.

Behavioral observation can be either obtrusive or unobtrusive measurement. This distinction refers to the extent to which the respondent or subject is aware that he or she is being evaluated. This awareness can affect both the internal validity and external validity of a study. Awareness can produce sensitization to the experimental manipulation, enhanced memory effects, reactivity to the research setting, and a host of other artificial effects which will obscure true relationships.
It is almost always the goal of a communication researcher to make observation as unobtrusive as possible. This can be done with careful design of the research setting or by choosing a measurement method that is inherently unobtrusive.

Reducing Obtrusiveness. Research settings can often be constructed so that the observer is inconspicuous or completely hidden.

For example, the children were observed through a one-way mirror which prevents the observed person from seeing the observer. The children may not have been aware of the purpose of a one-way mirror, but for older research participants the presence of a one-way mirror will be a dead give-away that they are being observed. This realization may affect behavior in unknown ways. But even if they realize that they are being observed from behind a mirror, there is a tendency to ignore the observer after a time, because there are no movements or noises from the observer to remind the subject that she is being observed.

If the subject suspects that he is being surreptitiously observed, he may actually react more strongly than if he is told that someone is behind the one-way mirror. The presence of a passive mirror or a small video camera in a discreet box are easily ignored after the novelty wears off, so it is often better to inform a subject that they are being observed that it is to allow them to have unconfirmed suspicions. Even if it is impossible to completely hide the observer, the obtrusive effect can be reduced by placing the observer in an out-of-the-way corner of the room and instructing him to remain as motionless and quiet as possible, to avoid rustling the coding sheets, etc.
There is a privacy issue involved with unobtrusive measurement.

Naturally Unobtrusive Measurement. Some types of observational measurement are inherently unobtrusive. This data is collected with little or no awareness by the sources of the data that communication research is being conducted.

For example, the mean income or number of telephones in urban census tracts could be useful variables for a telecommunications researcher. The U.S. Commerce department also collects detailed data about business organizations that can be used for similar aggregate analysis purposes. Governmental data is available at many public libraries and at most university libraries.

For the mass communication researcher, these archives are particularly useful when their information is combined with data from media archives which collect and preserve newspaper and magazine stories, television newscasts, television and radio commercials, and other media messages. Most large libraries carry the New York Times Index which can be used to summarize the frequency that newspaper stories about selected issues or topics appear. The Vanderbilt Television Archives publish an index of network television story coverage and can provide videotapes of stories about selected topics. The researcher can use a media archive to provide the material for a content analysis (described in more detail later in this chapter). The data from the content analysis, combined with data from a public opinion archive, can be used to track the relationship between media messages and aggregate audience response.
Archives of original documents like letters and manuscripts can also be a source of unobtrusive data to the researcher interested in analyzing messages.
For example, the organizational researcher might gain access to electronic mail messages in a sample of corporations, and use this information to study communication patterns within different types of organizations. She might also collect all the interoffice mail envelopes and code the sender’s and recipient’s departments to unobtrusively measure interdepartmental communication. This kind of measurement produces no demand characteristics and no sensitization of research subjects.

Reusing the data collected by other researchers (secondary analysis) is often a very efficient way to collect information. This measurement may or may not be considered obtrusive. For example, an interpersonal communication researcher might be able to gain access to interviews and transcripts at a research center for family communication and therapy. Since the research subjects were probably aware that their responses were being recorded, the data will be subject to some sensitization and social demand contamination. But if the subject of the interviews was, for example, establishment of rules for adolescents, and the communication researcher is interested in the dominance of the conversation by the mother or father, he can consider his dominance measurement as being unobtrusive.

There are many, many other sources of data for secondary analysis. Commercial research organizations often maintain databases that can be made available to academic researchers after their business value has disappeared.


Source:
-. http://www.slideshare.net/sladner/week08-unobtrusive-presentation
-. Webb, E.J, Campbell, D.T., Schwartz, R.D., & Sechrest, L. (1972). Unobtrusive measures: Nonreactive research in the social sciences. Chicago: Rand McNally.