Measuring Usability: Products Index

Products

	Survey Sample Size Package A 23 page how-to-guide and Excel calculator that computes sample sizes for rating scales and binary response items. This package allows you to easily answer the common question: What sample size do I need for my survey? It includes plenty of examples and tips for computing the right sample size based on the question type and response analysis.
	Quantitative Starter Package for Usability Testing A package of the popular How to Conduct a Quantitative Usability Test Report and four of the most commonly used excel calculators for getting started measuring and reporting usability with confidence.
	How to conduct a Quantitative Usability Test Do you know how to measure usability? Do you have questions about the benefits and process for conducting a quantitative usability test? I've assembled answers to the 72 most common questions that arise from measuring usability. In this 64 page report I provide concrete examples and plenty of data from a dataset of 120 usability tests, the latest usability research and my decade of experience conducting quantitative usability tests.
	Problem Frequency Calculator Estimate how many users will experience a problem you see in a small sample usability test by entering the number who encountered the problem and your sample size. Also estimate the probability you can detect problems given your sample size.
	Average Task Time Calculator An excel calculator for task times that provides an easy way to compute the geometric mean, confidence intervals and a 1-sample t-test to compare a sample against a benchmark.
	Usability Statistics Package Use these sets of calculators to compute the most common statistical tests on usability data. Compare small and large sample completion rates, compare task times, compare satisfaction scores, generate confidence intervals and compare a completion rate and task time to a criterion. This package takes the guess work out of what tests to perform on your usability data.
	Usability Statistics Package Expanded Calculate the common statistical tests, sample sizes and use some advanced statistical tests on usability data. This calculator package contains everything the Usability Statistics Package contains, but is expanded to included sample sizes calculators for margins of error and power calculations for comparing two applications. It also contains ANOVA and Chi-Square tests to compare multiple means or completion rates. This package takes the guess work out of what tests to perform on your usability data.
	Confidence Interval Comparison Calculator Compare the four different binomial confidence calculations: Adjusted-Wald, Wald, Exact and Score in an Excel spreadsheet. This calculator contains all the formulas for you to easily compare the methods and integrate them into your Excel workbooks.
	zScore Calculator An excel calculator that provides an easy way to find the area under the normal curve from a z-score or lookup a z-score from area (inverse look-up).
	A Crash Course in Z-Scores A complete and concise 42 page tutorial on how to compute, interpret and use of one of the most important concepts in statistics: z-scores. This crash course includes dozens of pictures, review questions and two full z-score look-up tables.