Without yet seeing the particulars of how cognitivism impacts learning, I realize that instinctively I have always felt that true learning, that which advances the individual, cannot happen without external input. If one does not take in new experiences (the stimuli) and respond to them in some way, one cannot be different from what one was before. At least, not measurably different. I can reason things out all I want, but unless and until it is challenged or validated in some way through external sensory input, it doesn't count as knowledge. It may be belief, or even faith, but I wouldn't count it as knowledge. For example, with regard to soapmaking, I may reason that because I am mixing olive oil with lye, I must be reacting a fatty acid with a base, and therefore the result must be soap (and where did I learn that, anyway?!), but until I see the result of combining the fatty acid with the base, and possibly combining too much acid with not enough base or too much base with not enough acid, I can't validate that saponification has occurred, or that the soap is safe to use. (Fun fact: to determine if the soap has too much unreacted lye in it, it is common to use the sense of taste! A quick touch of the tip of the tongue to the bar of soap will tingle a bit if there's leftover NaOH in it—what we soapers call a "zap.")
Applying these principles to instructional design naturally depends on the nature of the concepts being taught. In SAP, for example, which has been the focus of probably 90% or more of the coursework I develop and implement, of course users need to execute certain keystrokes or input data into fields, and if they do so correctly, a success message displays (reinforcement) along with the result (an invoice or order number). Most of the stimuli, as well as the reinforcement, are visual. But occasionally the stimuli are also auditory, as when the system beeps when incorrect information is entered. The auditory stimulus should cause the user to respond by seeking the error on the screen. In adult learning scenarios like this one, I feel it is important to design and develop such a course so that the correct process is taught first. This reinforces the correct steps of the procedure and gives immediate positive feedback (reward) for doing the procedure correctly. The user can learn how to solve errors later. Occasionally I see courses developed by others that, right out of the gate, "bake" an error into the process being taught. The developer feels this is a good way to teach new end users how to troubleshoot mistakes. I feel just the opposite: teaching them an incorrect process, on a small level, actually leads to punishment on a small level: enter the incorrect info, and you won't get your document number. (Not to mention the time and morale wasted.)
I am looking forward to seeing how cognitivism relates to behaviorism. I am hoping that the best instructional designs and the courses that arise from those designs leverage both behavioral and cognitive features to facilitate learning.