Devise and implement a strategy for data frame column names

[abnova]

My initial attempt to use multi-word column names with spaces in them was working OK until I started experiencing some issues with inability of some R code to parse them correctly. Brief research has lead me to answers to a question on StackOverflow (http://stackoverflow.com/questions/12744282/how-to-deal-with-spaces-in-column-names), which clarified the situation to me. Based on that, I think I need to devise a project-wide strategy for consistent naming of data frame columns. Implementing this strategy will include renaming the involved columns (using dot character or, better, underscore character to connect the words in a name) as well as modifying relevant source code, which refers to these column names and/or operates on them.