Categories and Checklists for Observational Research
 |
Researchers using structured observational methods specify in advance the behaviors or events to be observed and use record-keeping forms that yield numeric information. Observers using structured observation are still required to make some inferences and exercise judgment, but they are restrained with regard to the kinds of phenomena that will be watched and recorded.
The creativity of structured observation lies not in the observation itself but rather in the formulation of a system for accurately categorizing, recording, and encoding the observations. Because structured techniques depend on plans developed before the actual observation, they are not appropriate when researchers have limited knowledge about the phenomena under investigation.
Categories and Checklists
The most common approach to making structured observations consists of constructing a category system for classifying observed phenomena. A category system represents an attempt to designate in a systematic or quantitative fashion the qualitative behaviors and events transpiring in the observational setting. Considerations in Using Category Systems A critical requirement for a good category system is the careful and explicit definition of behaviors and characteristics to be observed.
Each category must be explained in detail with
an operational definition so that observers have relatively clearcut criteria
for determining the occurrence of a specified phenomenon. Virtually all
category systems do, however, require observers to make some inferences,
although there is considerable variability on this dimension.
In
this system, assuming that observers were properly trained, relatively little
inference would be required to allocate the infant's state to the proper
category. Other category systems, however, require considerable inference.
In scales like the AIMS, even when categories are defined in detail, a heavy inferential burden is placed on observers. The decision concerning how much observer inference is appropriate depends on a number of factors, including the research purposes and the observers' skills. Beginning researchers are advised to construct or use category systems that require only a moderate degree of inference.
Another consideration in structured category systems concerns the exhaustiveness of what is to be observed. Some category systems are constructed to classify all observed behaviors of a certain type (eg, all body movements) into mutually exclusive categories. A contrasting technique is to develop a non exhaustive system in which only particular types of behavior are categorized.
For example, if we were observing children's aggressive behavior, we might develop such categories as “strikes another child,” “calls other children names,” “throws objects around the room,” and so forth. In this category system, many behaviors (all those that are non aggressive) would not be classified. Such non-exhaustive systems are adequate for many research purposes, but they run the risk of providing data that are difficult to interpret.
When a large number of observed behaviors are unclassified, investigators may have difficulty placing categorized behaviors into a proper context. When observers use an exhaustive system that is, when all behaviors of a certain type, such as verbal interaction, are observed and recorded researchers must be careful to define categories so that observers know when one behavior ends and a new one begins.
Another essential feature is that referent behaviors should be mutually
exclusive. If overlapping categories are not eliminated, observers will have
difficulty deciding how to classify a particular observation. The underlying
assumption in the use of such a category system is that behaviors, events, or
attributes that are allocated to a particular category are equivalent to every
other behavior, event, or attribute in that same category.
Checklists for Exhaustive Systems
A category system is the basis for constructing a checklist, which is the instrument observers use to record observed phenomena. The checklist is usually formatted with the list of behaviors or events from the category system on the left and space for tallying the frequency or duration of occurrence of behaviors on the right.
In complex social situations with multiple actors, the right-hand portion may be divided into panels according to characteristics of the actors (eg, nurse/physician; male patients/ female patients) or by individual subjects' names or identification numbers. The observers' task with an exhaustive checklist is to place all behaviors in only one category for each element. By element, we refer to either a unit of behavior, such as a sentence in a conversation, or to a time interval.
To illustrate, suppose we were studying the problem-solving behavior of a group of public health workers discussing a new intervention for the homeless. Our category system involves eight categories:
(1) seeks information
(2) gives information
(3) describes problem
(4) offers suggestion
(5) opposes suggestion
(6) supports suggestion
(7) summarizes
8) Miscellaneous
Observers would be required to classify every group member's contribution using, for example, each sentence as the element in terms of one of these eight categories. Another approach with exhaustive systems is to categorize relevant behaviors at regular time intervals.
For example, in a category system for infants' motor activities, the researcher might use 15-second time intervals as the element; observers would categorize infant movements within 15-second periods. Checklists based on exhaustive category systems are demanding because the recording task is continuous.
Checklists for Non Exhaustive Systems
The second approach, which is sometimes referred to as a sign system, begins with a list of behaviors (or symptoms) that subjects may or may not manifest. The observer's task is to watch for instances of the behaviors on the list. When a behavior occurs, observers either place a check mark beside the behavior category to designate its occurrence or make a cumulative tally of the number of times the behavior occurred.
The resulting product is a kind of demography
of events transpiring in the observational period. With this type of checklist,
the observer does not classify all behaviors or characteristics of those being
observed, but rather identifies the occurrence of particular ones.
Rating Scales
The major alternative to a checklist for recording structured observations is a rating scale that requires observers to rate a phenomenon along a descriptive continuum that is typically bipolar. The ratings are quantified for subsequent statistical analysis. Observers may be required to rate behaviors or events at specified intervals throughout the observational period (eg, every 15 minutes), in much the same way that a checklist would be used.
Alternatively, observers may rate entire events or transactions after observations are completed. Postobservation ratings require observers to integrate a number of activities and to judge which point on a scale most closely fits their interpretation of the overall situation.
For example, suppose we were comparing the behaviors of
nurses working in intensive care units with those of nurses in other units.
After each 15-minute observation session, observers are asked to rate the
perceived degree of tension of nurses in each unit. The rating scale might take
the form of a graphic rating scale:
Global observational rating scales are often included at the end of structured interviews. For example, in a study of the health problems of nearly 4000 welfare mothers, interviewers were asked to observe and rate the safety of the home environment with regard to structural or potential health hazards to the children on five-point scales, from completely safe to extremely unsafe (Polit, London, & Martinez, 2001).
Rating scales can also be used as an extension of checklists, in which observers not only record the occurrence of a behavior but also rate some qualitative aspect of it, such as its magnitude or intensity. A particularly good example is Weiss's (1992) Tactile Interaction Index (TII) for observing patterns of interpersonal touch.
The TII comprises four dimensions: location (part of body touched, such as arm, abdomen); action (the specific gesture or movement used, such as grabbing, hitting, patting); duration (temporal length of the touch); and intensity. Observers using the index must both classify the nature and duration of the touch and rate the intensity on a four-point scale: light, moderate, strong, and deep.
When rating scales
are coupled with a category scheme in this fashion, considerable information
about a phenomenon can be obtained, but it places an immense burden on
observers, particularly if there is extensive activity.
Give your opinion if have any.