THE COCHRAN-ARMITAGE TEST TO ESTIMATE THE SAMPLE SIZE FOR TREND OF PROPORTIONS FOR BIOLOGICAL DATA

Mustafa Agah TEKINDAL; Ozlem GULLU; Ayse Canan YAZICI; Yasemin YAVUZ

doi:https://doi.org/10.17557/tjfc.33765

Article Details

THE COCHRAN-ARMITAGE TEST TO ESTIMATE THE SAMPLE SIZE FOR TREND OF PROPORTIONS FOR BIOLOGICAL DATA

Authors:

Mustafa Agah TEKINDAL | Ozlem GULLU | Ayse Canan YAZICI | Yasemin YAVUZ

Publisher:

Society of Fields Crop Science

Journal:

Turkish Journal Of Field Crops 2016 Vol.21 Issue 2, pp.286-297

Document Type:

Article

Publication Date:

12/2016

Document Language:

English

Document ID (Org No.):

2000636274

Frequency:

Bi-Annual

pISSN:

1301-1111

DOI:

https://doi.org/10.17557/tjfc.33765

Abstract:

 


The biological activity of a substance can be investigated through a series of experiments done with the
increased or decreased dosage of it. One of the purposes of such studies is to determine the trend of responses
based on dosage. In studies carried out for this purpose, appropriate sample size has an indisputable influence
on the reliability of the decisions to be made at the end of the study. There are various statistical methods for
determining the trend of proportions. One of them is the Cochran-Armitage test. In a categorical data
analysis, the trend between two variables with k categories can be determined through the Cochran-Armitage
test. This study aims to explore the sample size calculation method developed by Nam J. (1987) for the
Cochran-Armitage test. The power of the test was investigated in different numbers of categories and in
different sample sizes for each category when the least biologically significant differences changed as Type I
error was taken as 0.05. To this end, the study examined the results obtained by making 10000 repetitions for
each case through the Monte Carlo simulation method. When the least biologically significant differences
change at the end of simulation studies, the power of test highly varies in different combinations. When the
number of categories is 2, determination of trend requires working with very large samples. When the number
of categories is 3 or 4, the desired power can be obtained with smaller samples compared to the case where the
number of categories is 2. When the number of categories is over 4, a substantial increase is needed in sample
size to obtain the desired power. Change in marginal frequencies does not have much influence on sample size.

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Article Details

THE COCHRAN-ARMITAGE TEST TO ESTIMATE THE SAMPLE SIZE FOR TREND OF PROPORTIONS FOR BIOLOGICAL DATA

Authors: Mustafa Agah TEKINDAL | Ozlem GULLU | Ayse Canan YAZICI | Yasemin YAVUZ

Publisher: Society of Fields Crop Science

Journal: Turkish Journal Of Field Crops 2016 Vol.21 Issue 2, pp.286-297

Document Type: Article

Publication Date: 12/2016

Document Language: English

Document ID (Org No.): 2000636274

Frequency: Bi-Annual

pISSN: 1301-1111

DOI: https://doi.org/10.17557/tjfc.33765

Issues

Authors:

Mustafa Agah TEKINDAL | Ozlem GULLU | Ayse Canan YAZICI | Yasemin YAVUZ

Publisher:

Society of Fields Crop Science

Journal:

Turkish Journal Of Field Crops 2016 Vol.21 Issue 2, pp.286-297

Document Type:

Article

Publication Date:

12/2016

Document Language:

English

Document ID (Org No.):

2000636274

Frequency:

Bi-Annual

pISSN:

1301-1111

DOI:

https://doi.org/10.17557/tjfc.33765