Wednesday, June 25, 2014

New version of SSD for R is available

We wanted to let you know that the latest and greatest version of SSD for R is now available for download from CRAN:  Version 1.4.5

What's different about this version?  We fixed a BUG in the d-index.

This actually means, not only a correction to the Effectsize() function, but also a correction to an error in SSD for R:  An R Package for Analyzing Single-System Data.

On page 56, we display the effect size for Jenny's yelling.  With a slightly incorrect formula, we OVERESTIMATED the value for the d-index.  We initially reported a value of 2.011, but you will see below, with the correction, the actual value is 1.947.


The actual percentage change was very small, but we like precision!

And speaking of effect sizes, we will give you something to look forward - we will be adding Hedge's g to the next version of SSD for R, which will be up on CRAN at the end of July.

Finally, check out the home page of our website at:  www.ssdanalysis.com.  We are showing off the new cover of our book and provide you with links to where you can purchase it!

As always, feel free to contact us on our website:  https://www.ssdanalysis.com/Contact_Page.html

We like hearing from all of you!

Wednesday, June 11, 2014

Another student project - Evaluating services with a high school student


In this blog post, we will also feature the work of a student from our Spring 2014 semester.  This project was completed by Shuli Tsadok.

Shuli did her internship in a private high school, and she was working with Linda, a 10th grade student who was new to the school.  Linda was referred for social work services because she was extremely withdrawn both with peers and with teachers; she rarely interacted with other students and did not participate in class discussions.

To measure the problem, Shuli asked Linda’s teacher to record how many times Linda raised her hand in her English class.  The baseline period was two school weeks (n=10).  During that time, Linda raised her hand, on average, 0.5 times per class period (SD=0.707).

During this assessment period, Shuli hypothesized that Linda’s withdrawn behavior was a result of social anxiety caused by extreme shyness.  To intervene with Linda, Shuli chose exposure therapy in which Linda would be put in positions to interact with others more.  Linda was assigned to a group project with other students in which she would not only have to collaborate with her classmates in a somewhat unstructured manner, but she would also have to give a presentation to the class.  Additionally, Shuli would meet with Linda in public places and encouraged her to interact with others in these settings.  Finally, Linda was given a peer tutor, which encouraged interaction with at least one other student.

After the intervention was introduced, the mean number of times Linda raised her hand in class increased to 1 (SD=0.667).

A line graph comparing phases is displayed below:


To compare the phases, Shuli noted that there was no issue of trending or autocorrelation, so she used a t-test as a statistical method.  With a calculated p-value of 0.1211, Shuli noted that there were no statistical differences between the phases.  However, with few data points and the intervention moving in the right direction, Shuli looked at the effect of the intervention.  The effect size for this intervention indicated a small degree of change.

The overall question for this course was to evaluate how well an intervention was working for a particular client.  Shuli noted that this intervention was not particularly effective for this client.  When she thought about it, she concluded that the lack of meaningful positive change could have been attributed to an unavoidable interruption in social work services combined with the fact that Linda is extremely shy.  Perhaps an extremely shy teen may have benefited from a different intervention.

Shuli noted that the “results in this study cannot be generalized because the study was only done on one client for a very brief period of time.” 

While this intervention was not particularly helpful for this client, we believe that this type of information is extremely useful to social work practitioners – it is just as important to understand what does NOT work for a client as what does!  Nice evaluation, Shuli!

What do YOU think of Shuli's project?  Feel free to contact us here and check out some of the additions to our website!