There are different kinds of knowing.

These memories illustrate two very different kinds of knowing, articulated twenty years ago by Jerome Bruner (1972). He made the distinction between "knowing how" and "knowing that." His separation of these two kinds of knowing appealed to many educators and became widely cited in the literature of psychology and education. Knowing how to ride a bike seems substantively different from knowing that a bike has two wheels. The former is a skill; the latter is a property. But how different actually are these two kinds of knowing?

Very different, according to a growing body of evidence. Recently, Bruner's distinction has garnered support and attention from an unexpected quarter -- the neurosciences. Oddly enough, the critical findings first came from a group of amnesiacs who seemed unable to learn anything (Martinez and Kesner, 1991). It is a story that has relevance for understanding the ways in which children learn.

After some kinds of specific brain damage, patients develop a severe anterograde amnesia. They can normally remember events that occurred prior to their injury (retrograde memory) but seem unable to learn new information. Thus they may remember the name of their sixth grade teacher but be unable to remember the name of someone they met yesterday. Such patients not only fail to learn the names of new people whom they have met, they fail even to recognize that they have ever seen them before -- even after hundreds of introductions. The difficulty is not limited to names but to almost any new information. They cannot recall the name of a newly elected president, what day it is, or their new home address.

For decades it was commonly accepted that such patients could not learn any new information, that the anterograde amnesia was total. Further study, however, indicated that there were surprising discontinuities. The same patients who could not recognize their doctors from day to day could, in fact, learn how to solve a maze, do a puzzle, and ride a bike. Through practice, their skills improved, showing retention from one day to the next. A startling revelation was that this improvement in skill came without any apparent recognition of the task from day to day. The patients would fail to recognize the maze when it was presented, reacting as if they had never seen it before in spite of improved performance. When asked to recall how they solved the maze, the patients were completely unable to do so. In a fundamental way, they were learning how to solve the maze but not learning that they knew it.

These cases and other related findings led neuroscientists and cognitive scientists to develop new ideas about what learning and memory really are. From many different kinds of neurological research it has become clear that there is not one neurology of learning or one neurology of memory. Instead, we have a number of ways of knowing, learning, and remembering, and although they often operate in an integrated fashion, they are easily separable. Neuroscientists have discovered that different parts of our brain, even different chemistries, are critical to each kind of knowing (Martinez and Kesner, 1991).

The research in the neurosciences is dramatic, and it is not the only evidence that there is more than one way of knowing. Researchers from a variety of fields have recently argued that we have been far too narrow in our conception of what knowing is. The work of Howard Gardner in multiple intelligences is an important example in the field of education (1983, 1991).

Just as there are different ways of knowing, there are different methods of teaching -- each selected depending on the knowing involved. What does this mean for teaching? For many educators there is a growing realization that we have also been too narrow in our choice of teaching methods. Just as there is not one kind of knowing, there is not one method of teaching. Rather, the optimal conditions for learning -- the ideal pedagogy -- depend on the kind of knowing involved. This paper looks at two of those methods -- apprenticeship and exploration -- and their implications for literacy development.