Can't import data to Rapidminer properly

Question

The data I'm trying to import is here: http://archive.ics.uci.edu/ml/machine-learning-databases/car/

car.data 51 K

There are no missing values in this data, yet there are lots of "?"s in the rapidminer once I imported the data. I looked at to the source and those data, which shown as "?", do exist properly in the source. What may be the problem?

by the way, if I download that file it's extension is .data. How should I import that kind of files? I import it as if it is a .csv file and it looks ok at first but there are those "?"s.

Answer 1

It's been sometime since I have used Rapidminer, but AFAIK, you can import .data file by using csv Import Wizard and setting the file type to All Files.

Regarding the ? values, you would have the look at the settings while importing the file and may have to adjust the datatype in Step 4 of the Import Wizard (the dropdown menu)

Answer 2

Use the Read CSV operator to load the file.

In the "Data import wizard - Step 2 of 4 screen, find the Column Separation group box and select the radio button Comma ",". The default separator is the semicolon and car.csv is comma-separated.

In the next step-- "Data import wizard - Step 3 of 4"-- change the annotation for row 1 from Name to - (the dash character). This tells RapidMiner that the first row contains data and not column headers.