Assessment, Statistics, and Research

  Introduction to a Basic Study This post provides information about one way to evaluate a workshop or seminar. I will illustrate the process using a hypothetical example of forgiveness. Suppose you wanted to evaluate the effectiveness of a workshop on forgiveness.  You hypothesize that the group participating in the workshop would be more forgiving toward an offender than the group not receiving the forgiveness workshop. Get approval from your company, university, or other research review board. They usually have forms listing the information you need to provide. Recruit participants for your workshop. Obtain consent for the study. Select   a forgiveness program Select a survey to measure progress in forgiveness. Create two groups of people.     Group 1 gets the workshop now.     Group 2 gets the workshop later and will serve as a control group. Randomly assign volunteers to one of the two groups. Deliver the workshop. Assess the participants' pr...

In this post, I refer to a set of items to assess gratitude. The  Gratitude Questionnaire  uses six items and was published by McCullough, Emmons, and Tsang in 2002. I have written elsewhere about gratitude . People high in the virtue of gratitude are often high in other virtues as well such as optimism and life satisfaction. They also tend to be more religious. In a previous post, The Psychology of Gratitude , I list some suggestions to increase gratitude. Reliability In previous research, the authors found support for one factor. Coefficient alpha , a measure of interitem consistency, ranged from .76 to .84 in samples reported by the authors  (McCullough, Emmons, & Tsang, 2002; McCullough, Tsang, & Emmons, 2002). Rating the Scale Items When using the scale in surveys the items are rated on a 7-point scale from strongly disagree (1) to strongly agree (7). High scores indicate a higher level of self-reported gratitude. Here's the 7-point rating: 1 ...

Who would think that a simple statistic like a mean or a median would make a difference? In large samples involving thousands of people, and when data are normally distributed (close to the shape of a bell curve), the mean and median will be nearly the same. In fact, in a theoretical distribution called the normal curve , the mean , median , and   mode are in the middle. But, many samples are not normal distributions . Instead, the often contain extreme scores called outliers or a lot of scores bunched up at high or low levels ( skewed ). Sadly, even people that understand statistics, continue to report the mean as if they are not thinking about their samples. Suppose you work for a company where the top person earns $300,000 but most folks earn $30,000 to $60,000. Well that $300,000 is gonna skew results and the mean will look much higher than the median. I ran some fictitious data on a sample of 10 people. Nine earn between $30 and $60K and one earns $300K. The Mean ...