Abstract

When the independent variable’s values for an experiment span several orders of magnitude, good experimental design requires thoughtful consideration of which measurements should be taken, and how to present the resultant data. The use of a logarithmic scale is the best solution for presenting such a wide range of measurements. The author provides a straightforward approach for determining equally spaced values at which experimental measurements will be taken within the logarithmic range for the independent variable. An example that demonstrates the step-by-step calculations is provided to help students and/or researchers who are not familiar with this portion of experimental design.

Keywords: Selection of x-axis values; Sample size; Logarithmic scale; Graph plotting; Experimental design