Many students and some researchers are ignorant of the fact that any of the following practices are statistically invalid and could be considered to be ‘research-results manipulation’ (=cheating):
Repeating an experiment until the p-value becomes significant.
Reporting only a ‘typical’ (=nice-looking) replication of the experiment, and presenting statistics (tests of significance and/or parameter estimates such as means and standard errors) based only on this subset of the data.
Presenting a subset of the data chosen using a subjective criterion.
Not reporting that outliers have been removed from the data presented or used in analyses.
This video is from a talk by Prof. Ariel Novoplansky, who visited our campus some time ago. He gave this talk two years ago in Israel, and it is a good introduction to some of the current research questions that make plant physiological ecology a hot and exciting subject at the moment.
I noticed this morning an unexpected behaviour of .spct objects when manipulated using data.table syntax… they become data.table objects! Until I solve this problem please do not use data.table syntax for manipulating .spct objects. I will upload a bugfix release of package photobiology, after I make sure that all functions defined in the package behave as expected. This will happen later today or tomorrow.
[edited @ 14:14, 22 July 2014] This time the bug was not in the code I had written, but rather in the data.table package. The code has recently been corrected in the development version of data.table (1.9.3), but this version is not yet available through CRAN… I will most likely upload a binary archive of data.table 1.9.3 to the r4photo repository later today, and a new version of package photobiology marked as requiring this or later versions of data.table.