One response to the above argument is that it is merely an example of the sort of nitpickings that keep academic researchers in business and has little or nothing to do with the straightforward rules of thumb by which practitioners earn their keep. Regardless, there is a better reason to discard it. Even if Miller's numbers held up in all the conditions under which they actually fail, there would still be a problem. The problem is that memory span is a statistical concept. Consequently, it is perfectly meaningful to state that a particular individual has been shown to have a span of 6.25 items.
Memory span is an attempt to measure the average maximum capacity of short-term memory.
Moreover, it does not follow that if he can lift 100 kg half of the time that we can just knock off 20 or 30 kg and expect him to lift that over and over. Rather, we would need to find a weight that he can comfortably lift again and again. Knowing his maximum capacity reveals little about this more relevant figure. So, although memory span may be irrelevant, perhaps the fact that people can make absolute judgments about only 5-9 unidimensionally variable items should influence web design. The weakness of this argument is that web pages comprise stimuli such as words and images that vary along many dimensions at once.