เปรียบเทียบวิธี

	Crowding Norm Curve Analysis	Recreation Substitutability Analysis
สาขาวิชา	Sport Leisure Studies	Sport Leisure Studies
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	2008	1991
ผู้ริเริ่ม	Bo Shelby & Thomas A. Heberlein; Jerry J. Vaske & Lisa B. Shelby	Bo Shelby & Jerry Vaske; Seppo Iso-Ahola
ประเภท	Field-survey pipeline for perceived crowding and density norms	Applied analytic pipeline for recreation substitution
แหล่งต้นตำรับ	Shelby, B., & Heberlein, T. A. (1986). Carrying Capacity in Recreation Settings. Corvallis, OR: Oregon State University Press. ISBN: 9780870714269	Shelby, B., & Vaske, J. J. (1991). Resource and Activity Substitutes for Recreational Salmon Fishing in New Zealand. Leisure Sciences, 13(1), 21-32.
ชื่อเรียกอื่น	Perceived Crowding Analysis, Single-Item Crowding Measure, Crowding Norm Analysis, Density-Crowding Norm Assessment	Leisure Substitutability Analysis, Recreation Substitution Assessment, Activity-Resource Substitution Analysis, Substitutability of Leisure Behavior
ที่เกี่ยวข้อง	4	4
สรุป	Crowding norm curve analysis is a field-survey pipeline for measuring how crowded recreationists feel and for translating their evaluations of density into management standards. Its measurement backbone is the standard single-item 9-point crowding question introduced in Shelby and Heberlein's 1986 book Carrying Capacity in Recreation Settings, on which visitors rate how crowded a setting felt from 'not at all crowded' (1-2) to 'extremely crowded' (8-9). Perceived crowding is a normative evaluation, not a raw density: it is the negative judgment people make about the number of people or encounters they experienced. Vaske and Shelby's 2008 synthesis of thirty years and more than 180 studies showed that this single item behaves consistently, that respondents scoring 3 or higher are conventionally classified as feeling crowded, and that several ways of summarizing the scale correlate above .90. Paired with acceptability evaluations of different densities, the method yields social norm curves that locate the use level at which conditions become unacceptable — a basis for capacity standards.	Recreation substitutability analysis studies the interchangeability of leisure experiences, asking when and for whom one recreation activity, site, or time can acceptably replace another. Bo Shelby and Jerry Vaske's work, exemplified by their 1991 study of salmon fishing in New Zealand, organized substitution into distinct types, varying the activity, the resource or setting, the timing, or the strategy of participation, and measured anglers' willingness to accept each kind of substitute when their preferred option was unavailable. Seppo Iso-Ahola's 1986 theory framed substitution as a psychological process in which perceived freedom of choice is the critical mediator: people substitute more willingly when they feel they are choosing rather than being forced, and when the alternative shares the valued qualities of the original. The analysis combines a typology of substitution with measures of willingness conditioned on choice freedom, the quality of alternatives, and recreationists' specialization and commitment.