 Like induction, and unlike deduction, abduction is not necessarily truth-preserving: in the example above, it is still possible that the defendant is not guilty after all, and that some other, unexpected phenomena caused the evidence to emerge. But abduction is significantly different from induction in that it does not only concern the generalization of prior observation for prediction (though it may also involve statistical data): rather, abduction is often backward-looking in that it seeks to explain something that has already happened. The key notion is that of bringing together apparently independent phenomena or events as explanatorily and/or causally connected to each other, something that is absent from a purely inductive argument that only appeals to observed frequencies. Cognitively, abduction taps into the well-known human tendency to seek (causal) explanations for phenomena (Keil 2006).