Course Objectives

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Class Time and Place

Prerequisites

Blackboard

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This page is the general description of the course and suggested expectations for both the student and the expectations of the teacher.

Sample Size Determination

Formated version of this page for printing

To calculate the error for a given number of samples

If you have a set number of samples and want to know the absolute error use:

where d = the desired absolute error in plus or minus of the units of measure, s = the standard deviation, t_α = Student's t value for n - 1 degrees of freedom for the 1 - α level of confidence, and n = the sample size.

To calculate the number of samples needed

To calculate the number of samples needed for a given error level use:

where the variables are the same as above.

To calculate the number of plots in relative terms

To calculate the number of plots in relative terms use the following formula:

where the t and n variables are the same as above. c is the coefficient of variation in the percent form and E% is the desired error as a percent.

Chapter 5 - Sample Size Determination pages 173-178 in:

Krebs, C. J. 1989. Ecological Methodology. Harper and Row, Publishers. New York. 654 pp.

or

Chapter 8 - One-Sample Hypotheses pages 108-112 in:

Zar, J. H. 1984. Biostatistical Analysis. Prentice-Hall, Inc. Englewood Cliffs, New Jersey. 718 pp.