Make one sotc3 dataset

[hadley]

Is there a reason not to start out like this:

sotc <- bind_rows(sotc10, sotc09, sotc08)
by_year <- sotc %>% group_by(year)

it feels like it would simplify a lot of the code.

[AmeliaMN]

Honest reason it is not like that-- I started working on just the 2010 data for ease of use, long before I was aware of dplyr (perhaps before it existed?!).

Reason not to change the code is a combination of laziness and lack of understanding of what bind_rows() does. If I try the line you suggested, I get
Error: incompatible type (data index: 2, column: 'problem_1', was collecting: integer (dplyr::Collecter_Impl<13>), incompatible with data of type: factor In addition: Warning message: In rbind_all(list(x, ...)) : Unequal factor levels: coercing to character

The years are all slightly different in terms of the data they create, so I'm not sure it makes conceptual sense to combine them.