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Three sampling methods were used in gathering data from the Snyder-Middleswarth Natural Area in the virtual forest tutorial: systematic sampling, random sampling, and haphazard sampling.
The systematic sampling method had the fastest estimated sampling time of 12 hours and 34 minutes. In contrast, the random sampling method had an estimated sampling time of 12 hours and 44 minutes. The haphazard sampling method had the longest estimated sampling time of 12 hours and 59 minutes.
The percentage error of the two most common and two rarest species for each sampling method are summarised below:
As observed from Table 1.4, on average, when the percentage errors of the two most common with the two rarest species in each sampling method are compared, it can be observed that accuracy increases with greater species abundance.
Furthermore, the systematic sampling method was more accurate on average (21.1%) than the random sampling method (30.78%) or the haphazard method (37.1%).
This result was surprising, having previously assumed that a method employing more randomisation in sample selection would have a smaller percentage error in its data collection. Perhaps because the species density distribution did not vary considerably along the y-coordinate plane, the samples collected using the systematic sampling method were (on average) more representative of actual data than the random sampling method (which had selected areas at random to sample, regardless of the evident topographic gradient).
It would be interesting to observe whether the relative accuracies of the sampling strategies would change if a much larger sample size was tested. Additionally, if would be interesting to observe whether a stratified random sampling method would have greater accuracy than the systematic sampling method for the Snyder-Middleswarth Natural Area.
good presentation