Hi Im using WEKA for data mining and i have a project based on kid's usage of internet.I have downloaded the data from openML in .arff form and im processing them in Notepad i have changed the values "," to "." and "?" to ",". Although when i try to open the file in WEKA i get this
"nominal value not declaired in header, read line 76"
line 76 is the first information after @data
Error: error.png
The ARFF defines comma as the separator between columns. Replacing commas with periods essentially turned all columns into a single nominal value which wasn't defined for that column in the header. Nominal attributes require all possible values to be declared in the header section for that attribute.
What was the reason for converting commas to periods?