-one column of binary data (0 or 1)

-18 columns of variables which go roughly between -200 and 200

Aim:

To create a model which can predict the dependent variable based on the independent variables. In the future on data which is not available yet.

Note:

The model doesn't need to give a prediction (0 or 1) all the time. It's fine if the model would say "I don't know". That would be better than giving a wrong prediction on the dependent variable.

Does anybody have an idea of how to do this? If you use binary logistic regression I don't see how to include the "I don't know" part.