METHODS
Questionnaire design and administration
All VSP questionnaires follow design principles outlined in Don A. Dillman's book Mail and Internet Surveys: The Tailored Design Method (2000). The Joshua Tree NP questionnaire was developed at a workshop held with park staff to design and prioritize the questions. Some of the questions were comparable with VSP studies conducted at other parks; others were customized for Joshua Tree NP.
Interviews were conducted, and 700 questionnaires were distributed to a sample of visitor groups who arrived at Joshua Tree NP during the period from April 39, 2004. Table 1 presents the questionnaire distribution locations. These locations were selected by park staff and the proportion of questionnaires distributed was based on park visitation statistics.
| Table 1: Questionnaire distribution locations N=700 visitor groups | ||
| Sampling site | N | % |
| West Entrance Station | 245 | 35 |
| North Entrance Station | 147 | 21 |
| Cottonwood Visitor Center | 105 | 15 |
| Black Rock Canyon | 84 | 12 |
| Indian Cove | 70 | 10 |
| Oasis Visitor Center | 49 | 7 |
| Totals | 700 | 100 |
Visitor groups were greeted, briefly introduced to the purpose of the study, and asked to participate. If visitors agreed, an interview lasting approximately two minutes was used to determine group size, group type, and the age of the adult who would complete the questionnaire. These individuals were then asked for their names, addresses, and telephone numbers in order to mail them a reminder/thank you postcard.
Visitor groups were given a questionnaire and asked to complete it after their visit and then return it by mail. The questionnaires were pre-addressed and postage paid.
Two weeks following the survey, a reminder/thank you postcard was mailed to all participants. Replacement questionnaires were mailed to participants who had not returned their questionnaires four weeks after the survey. Seven weeks after the survey, a second round of replacement questionnaires were mailed to visitors who still had not returned their questionnaires.
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