The extrema in a signal and its first few derivatives provide a useful general-purpose qualitative description for many kinds of signals. A fundamental problem in computing such descriptions is scale: a derivative must be taken over some neighborhood, but there is seldom a principled basis for choosing its size. Scale-space filtering is a method that describes signals qualitatively, managing th...

This paper presents a qualitative-reasoning method for predicting the behavior of mechanisms characterized by continuous, time-varying parameters. The structure of a mechanism is described in terms of a set of parameters and the constraints that hold among them : essentially a 'qualitative differential equation'. The qualitative-behavior description consists of a discrete set of time-points, at...

The origins, cross-disciplinary evolution, and definition of “thick description” are reviewed. Despite its frequent use in the qualitative literature, the concept of “thick description” is often confusing to researchers at all levels. The roots of this confusion are explored and examples of “thick description” are provided. The article closes with guidelines for presenting “thick description” i...

One of the factors hindering the wide-spread application of qualitative simulation techniques is the difficulty encountered when developing a qualitative model . Analyzing the resulting behavioral description and revising the model in response to this analysis requires a significant amount of expertise and is often left up to the modeler. As a result, developing a qualitative model is difficult...

One of the factors hindering the wide{spread application of qualitative simulation techniques is the diiculty encountered when developing a qualitative model. Analyzing the resulting behavioral description and revising the model in response to this analysis requires a signiicant amount of expertise and is often left up to the modeler. As a result, developing a qualitative model is diicult for u...

The aims of this paper were to clarify the nature and purpose of qualitative research and to suggest specific guidelines for reporting the results of qualitative studies. Confusion about the purpose of qualitative research and the absence of a standardized format for reporting such research make it difficult to assess the validity of qualitative studies. Four general purposes of qualitative res...

English language practitioners have long relied on intuition-based scales for rating EFL/ESL writing. As these scales lack an empirical basis, the scores they generate tend to be unreliable, which results in invalid interpretations. Given the significance of the genre of description and the fact that the relevant literature does not introduce any data-based analytic scales for rating EFL descri...