Introduction to Statistical Modelling
Training session with Dr Helen Brown, Senior Statistician, at The Roslin Institute, December 2015.
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These training sessions were given to staff and research students at the Roslin Institute. The material is also used for the Animal Biosciences MSc course taught at the Institute.
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*Recommended Youtube playback settings for the best viewing experience: 1080p HD
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Content:
Repeated measures data
-Repeated measurements on same individual or ‘item’
---Eg repeated measurements on crabs of consumption of different diets
-Multiple measures on the same crab are not independent
-A GLM might seem appropriate:
-BUT only if data are complete
Repeated measures data – Possible approaches
-Analyse one measure for each individual
---Mean
---Area under curve
---Maximum value
---Time to maximum value
---One chosen timepoint
-Analyse all timepoints separately and adjust for multiple testing
-If data are complete could use a GLM with adapted test for comparing treatments
---Allows test of treatment, time and treatment*time interaction
---Data need to be complete
-Use a mixed model :
---Suitable for complete or incomplete data
- Tags
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