add comparison from one year to the next to my "todo"
scatterplots of easiness, time and level (same as script easiness_time_level), but allows us to compare two years
add entry about easiness_time_level_two_years.R
short new script to be able to work with last year's data
add info on new helper script
x done. Quick and dirty
first version cobbled together - the opposite of elegance
debug; set same xlim and ylim everywhere
update to-do list
changed "cognitive level" to "challenge level"
changed "cognitive level" to "challenge level"
add note about exporting data
export xlsx and csv files
time easiness excel export done
export data to xls and csv
update to-do after discussion with Henrike
fixed indexing problem
fixed another index problem (accidental swap of j and k)
no wait, that was right. but k starts at 3
fix import of correctness file