Initial mass function biases created by binning and unresolved systems

I discuss two of the possible sources of biases in the determination of the stellar initial mass function: binning and the existence of unresolved components. The first source is important for clusters with a small number of stars detected in a given mass bin, while the second is relevant for all clusters located beyond the immediate solar neighborhood. For both cases I present results of numerical simulations, and I discuss strategies to correct for their effects. I also present a brief description of a third unrelated bias source.