The students sitting in front of you represent a wide range of experiences, values and personal characteristics. They are products of a vast system of public schools and parent affluence. They are self-centered and materially influenced. They belong to a society conversant with MTV and are facile on the Internet.

The sum total of their formal education is thus influenced by the curriculum, the experiences, and philosophies deemed important by teachers; the school environment; and attitudes about school held by parents and community members. Additional important components in the ultimate determination of what any individual knows or doesn't know is developed outside the school. The determinants of what is potentially known by any individual will be influenced more strongly outside of school simply because of the greater amount of time spent outside the classroom. Biological factors also influence the acquisition of information. In fact, two biologically different individuals with identical school experiences will demonstrate different results on tests of educational achievement. Likewise, identical twins with identical school experiences will score differently on tests of educational achievement.
Kurt Lewin (1955) has reported the equation B=fPE as the simplest statement of the relationship between the biological and experiential influences of behavior. In his equation B= behavior is a functional relationship between the P, personal or genetic influences, and E, the environmental forces including such things as school, home, or diet.

What we know at any time or stage in our life then is complicated by many variables. The school's influence may be no more important than other environmental influences. Our biological uniqueness is critical too -- particularly our inherited instructions for synthesizing neurochemicals, cortical complexity and thalamic processing.

Whatever the combination of formal and informal experiences, each individual possesses a vast array of knowledge of information that represents the individual's known universe. No tests exist to measure a person's total knowledge base. Since the sum total of information owned by an individual is known only to that individual, it is not readily evident what total knowledge or skills a person may have. Thus, there is really no ready total comparison individual to individual. As Francis Crick (1994) has written, there are no sure neural correlates of what we know.

It is interesting to speculate, however, on the impact of being able to quantitatively determine every single facet of a persons known universe. Imagine first the array of all information known to humankind. An alphabetical listing of such a list would be huge. Second, if it were possible, it would be interesting to superimpose on the list of everything known, a list of what any single individual might know. Two things would be evident -- first, the master list represents information only observed and recorded by humankind. This information is incomplete because much is left unknown to humans. Second, anyone would immediately recognize how little any of us really knows about what is known. In fact it would immediately be apparent that what is known by a person is much less than what is unknown to that person.

Some philosophers have noted that what a person doesn't know impinges more directly on behavior than what the person does know. This seems to be contradictory to Levin's formula B=fPE, but the analog might also be true. In this case behavior is a functional relationship between genetic or biological determinants and environmental influences one doesn't possess or has experienced. The influence of teachers, parents, and the environments presented to children and youth are crucial to the developing brain -- but it is what the brain has not been exposed to that is perhaps most significant.

Another way of visualizing an individual's knowledge of the universe is to picture the known world as a circle. A student who is widely read, well traveled, nurtured appropriately at home and school has a circle of understanding and knowledge much larger than an individual unable to read or has never strayed far from home base. A world made acutely visible by the technology of television or the contents of a computer network must be bewildering to one whose personal universe is represented by a small circle.

The know/don't know relationship may be symbolized by the k/dk ratio. The higher the value the greater an individual's total understanding of the universe. A smaller value would predict a more limited world view. For example, if all of the world's knowledge were represented by 100, an individual who had a "know" value of 30 would have a "don't know" value of 70. Therefore, that person's k/dk ratio would be 30/70. If a second individual only had k=10, his k/dk ratio would be 10/90. Paradoxically, an individual whose known universe is small but who knows all there is to know about that limited universe may in a small sense have a high k/dk value. It is only when judged in the larger context that it is diminished.

The relative size of a student's world should increase in orderly developmental stages. By early adulthood an individual should have had enough experiences to know that one's destiny is created by one's own personal choice; that each person has the potential for creating the individual that he or she chooses to be. If one's experience base is shallow, stereotypic responses to external forces may create a helpless, confused stressed individual. Parents and teachers must work together to enhance a child's experiences. Identical problems faced by persons with widely different experience bases cause stress differently. Persons with large experience bases are able to cope and adapt more readily than those with less experience.

In addition to philosophical considerations about family life style, education and biological factors, the equation for understanding behavior must also include a look at time as a function of behavior. Regardless of the size of one's world, each person has only 24 hours per day to perform chosen tasks. Does it follow that a person with a larger world has the potential to contribute more to society than those without . . . ? It is obviously so. Persons who appreciate learning, understand the historical precedents to social concerns, and view themselves as incomplete but capable of promoting self-growth through choice of study have great potential. Those with a limited view of the universe are destined to grope ignorantly.

With so many educational philosophies, how can teachers arrive at the best approach? With so many life style and genetic variables at hand how should teachers attempt to personalize education? Perhaps it is time to agree that with so many choices available we should adapt an eclectic global style. With so much to know isn't the adoption of a single approach limiting? Perhaps it is time to espouse an approach to instruction that relies more on strong collaboration by all teachers about what to learn and what we assess as outcomes.