Anza Borrego Desert State Park - California State Parks - State of ...

Final Report – October 2001
Other information collected by the interviewers included: type of vehicle, date of contact,
location of contact, and interviewer. As they were completed, the surveys were
numbered and dated by each interviewer.
Twelve hundred surveys were administered during the November sampling period. Of
these, 1000 surveys (83% of total) were returned, and 853 (71% of total) were entered
into the database. The same numbers of surveys was also administered during March,
1100 of which (91%) were returned. One thousand, forty-one (86%) spring surveys
contained valid responses and were added to the data set. The rest of the surveys were
not usable for various reasons: incomplete responses, indeterminate responses, illegible
writing, etc.
The core aspects of the questionnaire were used at all six sample sites. One group of
questions, evaluating the acceptability of a range of environmental or management
conditions, was specific to each site. To judge preferred park conditions, visitors were
asked to view and rate the acceptability of a set of six computer-manipulated photos
depicting a range of potential conditions. The conditions presented in the six scenarios
were pre-selected, based on management issues and concerns communicated by Park
staff and by the public. In the Fish Creek and Blair Valley surveys, respondents rated the
acceptability of congestion in a large campground area. Photos depicted scenarios
ranging from no visible groups, to approximately 100 distinct groups. In Mountain Palm
Springs and Borrego Palm Canyon, visitors rated the acceptability of a range of trail
conditions, from primitive (low maintenance) to signed and paved (high maintenance and
engineering). In Coyote Canyon, respondents rated the acceptability of vegetation loss
due to off-road vehicle traffic. Scenarios presented in the six photos in the Coyote
Canyon series ranged from no visible impacts, to extensive vegetation loss. The Visitors’
Center survey did not include questions of acceptability using the photo series.
Non-participation Bias
Determined efforts were made by the interviewers to encourage selected visitors to take
the survey, especially those who were selected but seemed undecided about
participating. Once the visitor declined however, no further effort was made.
Consequently, it is possible that a degree of non-participation bias may be a factor in the
results. In any case, we consider that the relatively large sample size, coupled with the
randomization of sample sites, interviewers, and respondents would tend to reduce the
potential for non-response bias. A response rate of 70% (non-response = 30%) is
generally considered sufficient for most statistical and scientific rigor (Creswall, 1994,
Keppel, 1991; Salant and Dillman, 1994). Daily tallies and anecdotal information from
the interviewers suggests that the response rate in this study was greater than 70%.
Data Analysis
Data were coded using standard procedures and entered into a computer database.
Responses for each question, or category within a composite question, were entered
into the database. Fall data were entered from mid-January through mid-February 2001.
Spring data were entered April 2001 and both data sets were then merged into a
combined set, containing both seasons of data.
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