Another example of affirming the consequent concerns the distinction between a "rate-determining step" and a "product/selectivity-determining step." The latter term refers to an irreversible step that controls which of several possible products are formed in a reaction with multiple competing pathways. The product/selectivity-determining step can also be the rate-determining step, but the reverse statement-that the product-determining step needs to be the rate-determining stepis not necessarily correct. 10