# Posts Tagged ‘ statistical training ’

## When is a Multilevel Model not appropriate?

April 24, 2013
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I recently received this interesting question regarding Multilevel Models after one of my last blog posts: Question: Can you tell me when a multilevel-model is not appropriate? I have data that by design is clustered but the random intercept in the nul...

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## Multilevel Models Part 2: What is a Multilevel Model?

March 28, 2013
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Multilevel models (also called hierarchical linear models) are used to analyze clustered or grouped data, as well as longitudinal or repeated measures data. Consider the simple scenario shown below, where Y is continuous and is shown as a function of a...

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## Multilevel Models Part 1: Do I Need a Multilevel Model?

March 27, 2013
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If you have data where the observations are not independent due to nesting or clustering, you may need a multilevel model. Another scenario that would require a multilevel model is if you have data where observations have been gathered multiple times o...

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## ESTIMATE Statements – the final installment

May 2, 2012
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FINALLY…the simplest ESTIMATE statements to write are for continuous variables not involved in interactions or higher order terms. Consider a data set containing the 2004 SAT scores for each of the 50 states. The file includes the combined math and v...

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## "Easy button" for ESTIMATE statements

April 25, 2012
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My previous blog demonstrated the most difficult type of ESTIMATE statement to write—a two-way (or higher) ANOVA with interactions. An "easy button" for ESTIMATE statement comes by having a simpler model. Models with only main effects and no interact...

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## The magical ESTIMATE (and CONTRAST) statements

April 23, 2012
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When asked to select the best (or worst) of something in a business setting, do you wish you had "magic glasses" to see the answer? PROC GLM and other statistical modeling procedures have their own versions of such an item with their ESTIMATE (and CONT...

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## The Human Side of Statistical Process Control: Three Applications of SAS/QC You Might Not Have Thought About

March 22, 2011
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When you think of statistical process control, or SPC for short, what industry first comes to your mind? In the past 10 or 15 years, diverse industries have begun to standardize processes and administrative tasks with statistical process control. ...

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## Who Ate My Lunch? Discriminant Thresholds to Reduce False Accusations

February 18, 2011
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Lunch. For some workers, it’s the sweetest part of an otherwise bitter day at the grindstone. Nothing can turn that sweetness sour like going into the breakroom to discover that someone has taken your lunch and eaten it themselves. Nothing lik...

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