Fill in the blanks

1: Entropy is a measure of how many _____________ it takes to represent an observation on average.

2: Sampling is the main technique for _______________ the size of data from the population size to a manageable size.

3: When there is _______________ between two variables (attributes) then obtaining a linear boundary for classification is not possible.

4: Bias is related to ________________ as opposed to overfitting.