Abstract : The rationale for Fitts' law is that the pointing task has the information-theoretic analogy of sending a signal over a noisy channel, therefore matching Shannon's capacity formula. Yet, the currently received analysis is incomplete and unsatisfactory: there is no explicit communication model for the aiming task, there is a confusion between central concepts of capacity (mathematical limit), throughput (average performance measure) and bandwidth (physical quantity) and between source and channel coding so that Shannon's Theorem 17 can be misinterpreted. We develop an information-theoretic model for pointing tasks where ID is the expression of both a source entropy and a channel capacity when misses are not allowed; then extend the model to include mistakes at rate ε and prove that ID should be adjusted to (1 − ε)ID. Finally, we reflect on Shannon's channel coding theorem: Only minimum movement times, not performance averages, should be considered.