Former course III 2017

K III Statistics methods workshop

Current information on statistics training: see
www.uni-kassel.de/fb11agrar/de/fachgebiete-einrichtungen/umweltchemie/statistikschulungen.html

Analysis of variance with R for soil biologists and ecologists

Recommended prerequisites for participation: Basic knowledge of statistics and R (see contents of the two-day statistics intensive course I on March 9 and 10, in particular a confident handling of vectors and data frames and reading data into R is necessary). Basic knowledge of regressions and transformations (see contents of the two-day statistics intensive course II on March 13 and 14) is helpful, but not essential.

In the media and specialist journals of various disciplines, reference is repeatedly made to erroneous research due to inadequate knowledge of statistics (see e.g. Ainsworth (2007, Nature 448, 849): "The abysmal standard of statistical analysis in much of genetic epidemiology is little short of scandalous". There may also be similar problems in the soil sciences.

A major potential problem in soil science could be that some researchers are not even aware that there may be knowledge gaps that could lead to incorrect evaluations. Problem areas in the field of variance analyses can be, for example (i) a lack of understanding of the great importance of statistical independence of the data as a condition of variance analyses (dealing with spatially and/or temporally dependent data), (ii) ignorance of the importance of residual analyses and dealing with a lack of normal distribution or variance heterogeneity, (iii) hypothesis-free research with a focus on mechanically performed post hoc analyses, (iv) unfamiliarity with handling unbalanced designs, (v) a lack of understanding of more complicated designs (split plot) and (vi) inaccuracies in factor formulations.

The Intensive Course III is supported by the Commission III Soil Biology and Soil Ecology of the German Soil Science Society. The statistical principles for soil biologists and ecologists are to be further deepened so that the above-mentioned problem areas are less frequently encountered in soil science in the future.

Date: March 28, 2017 10:00 am to March 29, 2017 6:30 pm.

Location: University of Kassel, 37213 Witzenhausen, Nordbahnhofstr. 1a.

Costs: on request.

Number of participants: The number of participants is limited to 25.

Laptops: Please bring your own laptops with R and RStudio. If necessary, laptops can be borrowed with advance notice.

Materials: Course script, exercises and sample solutions will be provided.

Recommended literature: e.g. Crawley (2012). The R Book. 2nd Ed., Wiley.

Lecturer: Prof. Dr. Bernard Ludwig

Schedule of the intensive course:

Tue., 28.03.2017

10:00 - 12:00 Welcome, one-factorial Anovas (Analyses of Variance), construction of Anova tables, residual checks

12:00 - 13:00 Lunch break

13:00 - 14:00 Post-hoc tests for single factorial studies

14:00 - 16:30 Multi-factorial Anovas (blocking, interactions), exercises in R

16:30 - 17:00 Coffee break

17:00 - 18:30 Model simplifications and exercises in R

Wed., 29.03.2017

10:00 - 12:00 Post-hoc tests or contrasts; factor formulations & unbalanced model

12:00 - 13:00 Lunch break

13:00 - 14:00 Exercises in R with practical examples

14:00 - 16:30 Variance & regression analysis, splits

16:30 - 17:00 Coffee break

17:00 - 18:30 Exercises in R with practical examples

Please send registrations and queries by 01.03.2017 to: Prof. Bernard Ludwig, University of Kassel, bludwig@uni-kassel.de

Please understand that the intensive course may be canceled if there are not enough registrations. In this case, or if the course is canceled due to illness of the lecturer or other events beyond our control, no further claims can be made.