February 2, 2015

Meet Statistics summer scholar Ole Geldschlager

OleEvery year, the Department of Statistics offers summer scholarships to a number of students so they can work with staff on real-world projects. Ole, right, is working on a project called Testing data-model fitness in phylogenetics with Dr Steffen Klaere. Ole explains:

“A continuously elusive question in phylogenetic inference is how to test data-to-model fitness. While there have been omnibus tests available for more than 20 years, their applicability was restricted due to issues of power and computability of the test statistics.

“In recent work, we have assessed the fitness of each site (or observation) separately by fitting simultaneous confidence regions.

“However, the more appropriate choice would be to do informed multiple testing on the sites and identify those sites for which the test finds evidence against model fitness. My task is to investigate a number of potential tests and assess their strength and weaknesses through simulation approaches.

“The maximum likelihood approach for phylogenetic inference resembles to some degree a logistic regression approach. Here, one uses deviance measures to assess the model-data fitness. Such approaches have been tested in phylogenetics as well, however, they often ignore the fact that the data are over-dispersed and zero-inflated.

“Consequently, in my project I will investigate the suitability of corrections to the deviance made by ecologists to account for overdispersion and zero-inflation to build statistics which are suitable to test model-data-fitness in phylogenetics.

“I am studying a masters in mathematics at the Ernst-Moritz-Arndt University Greifswald in Germany. I have a bachelor’s degree in biomathematics, also from Greifswaldl.

“Statistics is one of my favourite topics in mathematics. Statistics plays a big role in finance, economy and nature, and that’s why I want to learn and understand statistics.

“Over summer, I am looking forward to travelling around New Zealand. I want to learn more about this exciting country – it is completely new to me.”

 

 

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Atakohu Middleton is an Auckland journalist with a keen interest in the way the media uses/abuses data. She happens to be married to a statistician. See all posts by Atakohu Middleton »