PLOTSAM: A simulation of systematic and random sampling
Technical Report
·
OSTI ID:6700298
PLOTSAM the computer program, that simulates sampling of organisms or environmental conditions, is described. The program has three major components: a specification of the location and the statistical characteristics of the organisms or conditions, a sampling, and a computation of statistical tests. With PLOTSAM, the location of the organisms or site conditions can be specified as a systematic or bivariate normal distribution, and the attributes can have a normal, lognormal, uniform, or triangular distribution. Furthermore, sampling can be performed by placing quadrats randomly or systematically along one or more transects in a square plot. Descriptive statistics of the complete and sampled data sets can be examined. Then statistical tests can be performed to compare the complete and sampled data sets. The advantage of using a simulation for sampling is that the sampled information can be compared to the complete population and that the accuracy and precision of the sampling methods thus can be tested. Knowledge of the adequacy of the sampling regime is otherwise difficult to obtain in many ecological studies because the populations are frequently so large that collecting all of the measurements is not feasible. Using PLOTSAM, a test is performed to examine the effects on the estimates of the mean and the variance when the number of samples is increased and different distributions of the attribute are simulated. This test was parameterized with values obtained from a sampling of available soil nitrogen with ion exchange resin bags. The simulations suggest that the increase in accuracy associated with an increase in sample number is related to the skewness and kurtosis of the true population. 16 refs., 8 figs., 7 tabs.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6700298
- Report Number(s):
- ORNL/TM-10670; ON: DE89004249
- Country of Publication:
- United States
- Language:
- English
Similar Records
Bivariate model for the distribution of. sqrt. b/sub 1/ and b/sub 2/
A brief overview of kurtosis
Power transformation of the sample kurtosis
Journal Article
·
Mon Feb 28 23:00:00 EST 1977
· J. Am. Stat. Assoc.; (United States)
·
OSTI ID:5389628
A brief overview of kurtosis
Conference
·
Mon Nov 30 23:00:00 EST 1998
·
OSTI ID:677174
Power transformation of the sample kurtosis
Conference
·
Wed Dec 31 23:00:00 EST 1986
·
OSTI ID:6228536