# All

## Preparing for the 4th Industrial Revolution

For some time now, I have been watching the downward slide in income and wealth of the American middle class while the income and wealth of those who control capital have soared. Part of this is due, of course, to the accelerating transfer of traditional manufacturing to countries with lower labor costs and with less …

## Setting up Hypothesis Tests

The Null and Alternative The most common problem I noticed on this assignment was caused by failing to properly identify the appropriate null and alternative hypotheses. In part, this is due to the Evans text’s somewhat confusing explanation of how to do this – the “burden of proof” approach. There is a much simpler approach …

## Still the “Old Statistics” being taught?

In the last few years, there has been continuing press about the shortcomings of the traditional hypothesis test. And it seems that the American public writ large is totally confused about what a “significant” research result really is. I have been wanting to find a way to include discussion of effect sizes and confidence intervals …

## Test Jing free screencast app

Update 3-22-2015: the more I use the “golden dot,” the more I like it. I often take static screen shots for one reason or another. In the past, I used Windows Ctrl-PrtScr and then opened Photoshop or Gimp and pasted the image in for editing. But with Jing, the ‘dot’ is always active and all …

## Example problem re: Goodness of Fit test:

You are given a six-faced die and asked to determine with 95% confidence if it is “fair.” What are the hypotheses? Answer: the null H0: the die is fair, p1 = p2 = … = p6 = 1/6; the alternative Ha: the die is not fair, at least one pi ≠ 1/6. What is the …

## Zero Correlation?

I can see your confusion. To understand why I said that variables that have “zero correlation” might still be related, you need to remember that we were speaking of traditional correlation which is a linear relationship. We were discussing the Pearson moment correlation which we designate as “r.” An r of zero tells us that …