scholarly journals Abundance of sea lice larvae in plankton samples: Determination of optimal sample sizes

Aquaculture ◽  
2022 ◽  
pp. 737919
Author(s):  
V. Fernandez-Gonzalez ◽  
E.M. Ulvan ◽  
P. Sanchez-Jerez ◽  
O.H. Diserud ◽  
K. Toledo-Guedes ◽  
...  
Keyword(s):  
Sea Lice ◽  
Sample Sizes ◽  
Optimal Sample

Determination of Optimal Sample Sizes in the Beta-Binomial Brand Choice Model

1980 ◽  
Vol 17 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Moshe M. Givon
Keyword(s):  
Stochastic Models ◽  
Choice Behavior ◽  
Choice Model ◽  
Brand Choice ◽  
Binomial Model ◽  
Sample Sizes ◽  
Estimation Of Parameters ◽  
Optimal Sample

Estimation of parameters in stochastic models of brand choice behavior requires the determination of two sample sizes: the number of consumers and the number of purchase occasions observed for each consumer. A method for determination of optimal sample sizes is presented and illustrated by an application to the beta-binomial model.

scholarly journals Optimal sample sizes for group testing in two-stage sampling

2014 ◽  
Vol 25 (01) ◽  
pp. 12-28 ◽  
Author(s):  
Osval Antonio Montesinos-López ◽  
Kent Eskridge ◽  
Abelardo Montesinos-López ◽  
José Crossa
Keyword(s):  
Group Testing ◽  
Sample Sizes ◽  
Two Stage ◽  
Optimal Sample

scholarly journals The Determination of Sample Size for Sensitive Issue Successive Survey with the Multiplication RRT Model under Two-Stage and Stratified Two-Stage Random Sampling and Its Application in Medical Survey

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Bo Yu ◽  
Xiaonan Liang ◽  
Ying Wang ◽  
Yun Liu ◽  
Qiao Chang ◽  
...  
Keyword(s):  
Sample Size ◽  
Sampling Method ◽  
Sampling Errors ◽  
Two Stage ◽  
Successive Sampling ◽  
Optimal Sample ◽  
Sensitive Issue ◽  
Survey Accuracy ◽  
The Cost

When designing the sample scheme, it is important to determine the sample size. The survey accuracy and cost of survey and sampling method should be considered comprehensively. In this article, we discuss the method of determining the sample size of complex successive sampling with rotation sample for sensitive issue and deduce the formulas for the optimal sample size under two-stage sampling and stratified two-stage sampling by using Cauchy-Schwartz inequality, respectively, so as to minimize the cost for given sampling errors and to minimize the sampling errors for given cost.

Use of Ten Gram Samples of Corn for Determination of Mycotoxins

1988 ◽  
Vol 71 (1) ◽  
pp. 41-43
Author(s):  
Octave J Francis ◽  
George M Ware ◽  
Allen S Carman ◽  
Gary P Kirschenheuter ◽  
Shia S Kuan
Keyword(s):  
Statistical Tests ◽  
Automated System ◽  
Sample Sizes ◽  
Concentration Variance ◽  
Assay Procedure ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Aflatoxin B ◽  
Test Result

Abstract Data were gathered, during a study on the development of an automated system for the extraction, cleanup, and quantitation of mycotoxins in corn, to determine if it was scientifically sound to reduce the analytical sample size. Five, 10, and 25 g test portions were analyzed and statistically compared with 50 g test portions of the same composites for aflatoxin concentration variance. Statistical tests used to determine whether the 10 and 50 g sample sizes differed significantly showed a satisfactory observed variance ratio (Fobs) of 2.03 for computations of pooled standard deviations; paired f-test values of 0.952, 1.43, and 0.224 were computed for each of the 3 study samples. The results meet acceptable limits, since each sample’s r-test result is less than the published value of the |t|, which is 1.6909 for the test conditions. The null hypothesis is retained since the sample sizes do not give significantly different values for the mean analyte concentration. The percent coefficients of variation (CVs) for all samples tested were within the expected range. In addition, the variance due to sample mixing was evaluated using radioisotopelabeled materials, yielding an acceptable CV of 22.2%. The variance due to the assay procedure was also evaluated and showed an aflatoxin B, recovery of 78.9% and a CV of 11.4%. Results support the original premise that a sufficiently ground and blended sample would produce an analyte variance for a 10 g sample that was statistically comparable with that for a 50 g sample.

Sample size for qualitative research

2016 ◽  
Vol 19 (4) ◽  
pp. 426-432 ◽  
Author(s):  
Clive Roland Boddy
Keyword(s):  
Qualitative Research ◽  
Sample Size ◽  
Single Case ◽  
Short Paper ◽  
Sample Sizes ◽  
Homogeneous Population ◽  
Content Type ◽  
Data Saturation ◽  
Theoretical Saturation

Purpose Qualitative researchers have been criticised for not justifying sample size decisions in their research. This short paper addresses the issue of which sample sizes are appropriate and valid within different approaches to qualitative research. Design/methodology/approach The sparse literature on sample sizes in qualitative research is reviewed and discussed. This examination is informed by the personal experience of the author in terms of assessing, as an editor, reviewer comments as they relate to sample size in qualitative research. Also, the discussion is informed by the author’s own experience of undertaking commercial and academic qualitative research over the last 31 years. Findings In qualitative research, the determination of sample size is contextual and partially dependent upon the scientific paradigm under which investigation is taking place. For example, qualitative research which is oriented towards positivism, will require larger samples than in-depth qualitative research does, so that a representative picture of the whole population under review can be gained. Nonetheless, the paper also concludes that sample sizes involving one single case can be highly informative and meaningful as demonstrated in examples from management and medical research. Unique examples of research using a single sample or case but involving new areas or findings that are potentially highly relevant, can be worthy of publication. Theoretical saturation can also be useful as a guide in designing qualitative research, with practical research illustrating that samples of 12 may be cases where data saturation occurs among a relatively homogeneous population. Practical implications Sample sizes as low as one can be justified. Researchers and reviewers may find the discussion in this paper to be a useful guide to determining and critiquing sample size in qualitative research. Originality/value Sample size in qualitative research is always mentioned by reviewers of qualitative papers but discussion tends to be simplistic and relatively uninformed. The current paper draws attention to how sample sizes, at both ends of the size continuum, can be justified by researchers. This will also aid reviewers in their making of comments about the appropriateness of sample sizes in qualitative research.

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