Blog Archives

JSM 2013 – Wednesday

August 8, 2013
By

I was able to attend a continuing education short course workshops at the JSM conference that proved to be quite insightful.  The discussion was on data mining and was titled “Applied Data Mining Analysis: A Step-by-Step Introduction Using Real-World Data Sets”.  The presentation was given by Dan Steinberg and the examples that he gave were

Read more »

JSM 2013 – Tuesday

August 7, 2013
By
JSM 2013 – Tuesday

The Joint Statistical Meeting in Montreal has proven to be very good.   Here are a few highlight from Tuesday’s sessions.  There is one major problem that exists and that is there are too many good sessions to attend.  During one time block I had six session that I wanted to go to.  Unfortunately, it

Read more »

JSM 2013 – Monday

August 6, 2013
By
JSM 2013 – Monday

I am currently attending the 2013 Joint Statistical Meeting in Montreal. I will try to share a few if the things that I take away each day. Last night (Monday) I attended the JSM keynote speaker with Nate Silver and it proved to be a very interesting discussion.  Silver is best known for his work

Read more »

Imputing Missing Data With Expectation – Maximization

July 14, 2013
By
Imputing Missing Data With Expectation – Maximization

It can be fairly common to find missing values in a dataset. Having only a few missing values isn’t generally a problem and those records can be deleted listwise. In other words the entire record is simply removed from the analysis. The problem is even with a limited amount missing data, that can translate into

Read more »

Some Common Approaches for Analyzing Likert Scales and Other Categorical Data

July 1, 2013
By
Some Common Approaches for Analyzing Likert Scales and Other Categorical Data

Analyzing Likert scale responses really comes down to what you want to accomplish (e.g. Are you trying to provide a formal report with probabilities or are you trying to simply understand the data better). Sometimes a couple of graphs are sufficient and a formalize statistical test isn’t even necessary. However, with how easy it is

Read more »

Using R to Produce Scalable Vector Graphics for the Web

June 30, 2013
By
Using R to Produce Scalable Vector Graphics for the Web

Statistical software is normally used during the analysis stage of a project and a cleaned up static graphic is created for the presentation.  If the presentation is in web format then there are some considerations that are needed. The trick is to find ways to implement those graphs in that web format so the graph

Read more »

Software Packages for Graphs and Charts

June 17, 2013
By
Software Packages for Graphs and Charts

Graphs can be an important feature of analysis. A graph that has been well designed and put together can make summary statistics much more readable and increase the interpretability. It also makes reports and articles looks more professional. There are many software packages that are available to design great graphs and charts.  This seems to

Read more »

Latent Class Modeling Election Data

June 14, 2013
By
Latent Class Modeling Election Data

Latent class analysis is a useful tool that is used to identify groups within multivariate categorical data.  An example of this is the likert scale. In categorical language these groups are known as latent classes. As a simple comparison this can be compared to the k-means multivariate cluster analysis. There are several key differences between the

Read more »

Hey, I Just did a Significance Test!

June 7, 2013
By
Hey, I Just did a Significance Test!

I’ve seen it happens quite often. The sig test. Somebody simply needs to know the p-value and that one number will provide all of the information about the study that they need to know. The dataset is presented and the client/boss/colleague/etc invariably asks the question “is it significant?” and “what’s the correlation?”. To quote R.A.

Read more »

Will Mu Go Out With Median

May 28, 2013
By
Will Mu Go Out With Median

True story (no really, this did actually happen).  While in grad school one of the other teaching assistants was approached by one of the students and was asked “will mu go out with median?”  The teaching assistant thought the play on words was pretty funny, laughed, and then cluelessly walked away.  All of us other grad students

Read more »