Monday, September 29, 2014

Slate & Rojas-LeBouef's "Presenting and Communicating Your Statistical Findings: Model Writeups"

Holy smokes. This e-book (distributed for free via Open Stax) contains sample result sections for multiple statistical tests, which is helpful but not particularly unique. There are other resources for creating APA results sections (love U. Washington's resources) but I feel that this book is particularly useful in that:

1) It addresses how to include effect sizes in tests (most of the result section examples I have been able to find neglect this increasingly important aspect of data analysis).
2) The writers translate SPSS output into results sections.
3) The writers aren't psychologist but they are APA compliant (and even point out instances when their figures and tables aren't APA compliant).
4) It is gloriously free.

The only shortcoming is that they don't provide examples for more types of data analyses. The book does, however, cover chi-square, correlation, t-test, and ANOVA, so most of what is covered in introductory statistics courses.

I think this book provides good examples to those of us to teach statistics and are starting to integrate more of the "new statistics" into our teaching. I think this would also be a great resource that is accessible enough for intro students but I bet that graduate students could make use of this book as well.

Thursday, September 25, 2014

Kristoffer Magnusson's" Understanding correlations, an interactive visualization"

Kristoffer Magnusson is a psychology graduate student with a background in web design and he is using his talents to create succinct, beautiful visualizations of statistical concepts. Below is a screen shot of his interactive tool for better understanding correlation and how it relates to shared variance (users can change the n-size and r and watch the corresponding changes in shared variance and the scatter plot). Follow Magnussen's work and statistical visualizations via @rpsychologist.

Special thanks to Randy McCarthy for recommending this resource!
Using the "Slide me" bar at the top, you can adjust the correlation in order to visualize the scatter plot, slope, and shared variance.

Monday, September 22, 2014

Center for Open Science's FREE statistical & methodological consulting services

Center for Open Science (COS) is an organization that seeks "to increase openness, integrity, and reproducibility of scientific research". As a social psychologist, I am most familiar with COS as a repository for experimental data. However, COS also provides free consulting services as to teach scientists how to make their own research processes more replication-friendly

As scholars, we can certainly take advantage of these services. As instructors, the kind folks at COS are willing to provide workshops to our students (including, but not limited to, online workshops). Topics that they can cover include: Reproducible Research Practices, Power Analyses, The ‘New Statistics’, Cumulative Meta-analyses, and Using R to create reproducible code (or more information on scheduling, see their availability calendar).

I once heard it said that the way you learn how to conduct research and statistics in graduate school will be the way you are inclined to conduct research and statistics for the rest of your professional life. As such, why not introduce our students (both graduate and undergraduate) to an aspect of data collection and analysis that both cultivates ethical behavior and is a growing expectation for publication in our top journals?  

Thursday, September 18, 2014

So I wrote a book: Shameless self-promotion 4

When I'm not busy thinking about statistics and research methods, I like to think about positive psychology. I like to think about it so much that I co-authored a positive psychology book with Rich Walker (Winston-Salem State University) and Cory Scherer (Penn State - Schuylkill). The book is called Pollyanna's Revenge and published by Kendall-Hunt. And the book makes a case for the fact that (contrary to many pop-psych reports) there are many good side effects to being a Pollyanna and that our minds engage in all manner on non-conscious processes that help us maintain positive affect (with special attention paid to the role of the Fading Affect Bias and memory in maintaining good moods).

Cross-promotion, y'all!

Monday, September 15, 2014

minimaxir's "Distribution of Yelp ratings for businesses, by business category"

Yelp distribution visualization, posted by redditor minimaxir

This data distribution example comes from the subreddit r/dataisbeautiful (more on what a reddit is here). This specific posting (started by minimaxir) was prompted by several histograms illustrating customer ratings for various Yelp (customer review website) business categories as well as the lively reddit discussion in which users attempt to explain why different categories of services have such different distribution shapes and means.

At a basic level, you can use this data to illustrate skew, histograms, and normal distribution. As a more advanced critical thinking activity, you could challenge your students to think of reasons that some data, like auto repair, is skewed. From a psychometric or industrial/organizational psychology perspective, you could describe how customers use rating scales and whether or not people really understand what average is when providing customer feedback.

Thursday, September 11, 2014

Cory Turner's "A tale of two polls"

LA Johnson for NPR
Cory Turner, reporting for NPR, found that differences in survey word choice affected research participant support of the Common Core in education. The story follows two polling organizations and the exact phrasing they used when they asked participants whether or not they support the Common Core. Support for the Core varied by *20%* based upon the phrasing (highlighted below):

Education Next Question:
"As you may know, in the last few years states have been deciding whether or not to use the Common Core, which are standards for reading and math that are the same across the states. In the states that have these standards, they will be used to hold public schools accountable for their performance. Do you support or oppose the use of the Common Core standards in your state?" (53% support)

PDK/Gallup Question:

"Do you favor or oppose having the teachers in your community use the Common Core State Standards to guide what they teach?" (33% support)

Turner speculates that people love the idea of accountability and that the use of that word by Education Next (as well as more contextual information) leads to the difference in support.

I used this example in my statistics class in order to emphasize the importance of word choice when creating scales. 

Monday, September 8, 2014

University of Manchester's Academic Phrasebank

One consistent problem I find in undergraduate writing is a tendency towards flowery prose. I think it is one of the reasons that APA style can be so difficult to teach: The less-is-more approach to concise writing is not a lesson that they are necessarily getting from other classes. To further muddy the waters, students really don't have any experience writing about numbers/data/statistics/results in a way that a) doesn't convey too much certainty in data or b) imply causality when not appropriate.

That is why I love the Academic Phrasebank. It provides lists and lists and lists of concise, accurate ways to describe research findings. For example, how to write up statistical results:
In addition to providing examples for wording in a results section, they also clarify the type of  guarded language that should be used in a discussion:
Another non-statsy/researchy aspect undergraduate writing pet peeve of mine is when student do not connect their sentences and paragraphs into a cohesive narrative (full disclosure: This is something I struggled with in graduate school). This site has a whole section devoted to connecting paragraphs, sentences, ideas together.

While this collection isn't explicitly APA-compliant, I would say that it embraces the spirit of APA style.

Monday, September 1, 2014's linear equation Flash applet

When I teach regression, I usually introduce the regression line by reminding my students of the long-ago days of algebra class and graph paper and rulers. has created an interactive applet that mimics the graph paper and allows users to adjust the y-intercept and the slope. This is a slightly fancier, more high-tech way to get your students thinking about the linear equation and then fitting that old knowledge into the new concept of regression.

Use the bars to adjust slope and y-intercept as a quick linear equation primer before teaching regression