Presidential Address Out of the Mouths of Babes: What Children Can Tell Us

Citation:

Deborah Roedder John (1997) ,"Presidential Address Out of the Mouths of Babes: What Children Can Tell Us", in NA - Advances in Consumer Research Volume 24, eds. Merrie Brucks and Deborah J. MacInnis, Provo, UT : Association for Consumer Research, Pages: 1-5.

Advances in Consumer Research Volume 24, 1997      Pages 1-5

PRESIDENTIAL ADDRESS

OUT OF THE MOUTHS OF BABES: WHAT CHILDREN CAN TELL US

Deborah Roedder John, University of Minnesota

The theme of this year’s conference is "Breaking Out of the Box." This morning, in the plenary session, we heard several viewpoints about the boxes we find ourselves in as consumer researchers. Though boxes have their advantages and disadvantages, the theme of the conference certainly suggests that breaking out of boxes is a worthwhile endeavor.

Extending this theme, I would like to take this opportunity to talk about a box that I have spent an entire career trying to stay out of-and encouraging others to do so as well.

The box I’m talking about is the "adult" box. Most consumer research is about adults, those famous 18-54 year-olds revered by practitioners and academics alike. Added to this, almost all of our research is guided by theories developed by scholars in other fields that also focus most of their attention on adults. Though we have enthusiastically adopted ideas from diverse areas-such as cognitive psychology, sociology, and anthropology-we have yet to fully appreciate what areas such as child psychology and developmental psychology have to offer.

I found my way out of the adult box quite by accident. As a first year student in the doctoral program at Northwestern, I had to take the traditional consumer behavior seminar from Sid Levy. Of course, since Sid Levy was giving the seminar, it was anything but traditional! As part of this seminar, we were required to write aliterature review on a topic of our choice. Not knowing much about consumer behavior, I picked a topic that I found interesting from a public policy angle, namely television violence and its effects on children.

I spent the next two months stationed at the copy machines in the library. I found out that the topic of media violence and children had spawned an enormous literature, which contained the most amazing set of theories from areas such as psychology, sociology, and child psychology. Of these, the ones I found most interesting came from child development, as researchers studied the issue from the vantage point of how children processed and interpreted violent behaviors found in television programs. Here, I found discussions about children’s memory, selective attention, moral judgments, and such. What I found interesting, and still find interesting, was how cognitive and social development provided a frame for understanding the world around us.

As time has gone by, I have often wondered why more of my colleagues haven’t been drawn into the study of children’s consumer behavior. But, more importantly, I’ve often wondered why more researchers haven’t seen child psychology as offering ideas and insights that might shed light on research related to adults. I’ve come to the conclusion that a lot of us are imprisoned in an adult box. Once we define our subjects as adults, we believe that there’s little to be gained from looking at similar issues in literature concerned with children and their development. With so many possible literature bases to look at, it’s probably a survival instinct that keeps us from churning through every conceivable area of scholarly research for insights. Yet, the adult box is still a box, with all the attendant disadvantages of ignoring potentially fruitful areas such as cognitive development.

My talk today has one main purpose. It is to convince you to get out of the adult box and take a look at what child psychology has to offer, whether you are interested in children or adults as consumers. Realistically, this is a task that should take longer than the 25 minutes I have left with you. But, what I will try to accomplish is to simply point out a few areas of research that could and should shed light on how we think about adult consumer behavior. To do so, I am going to focus on the topic of knowledge and knowledge development, which is a key area of intersection between consumer research and cognitive development. Children, and the research about them, have something to say to us... if we are willing to listen.

DESCRIBING KNOWLEDGE DEVELOPMENT

What We Know

Over the last decade, consumer researchers have been increasingly interested in understanding how different levels of knowledge impact consumer behavior. Examinations of this variety have featured comparisons between experts and novices or between consumers who have low, medium, or high degrees of knowledge in an area. These studies have provided insights into how different levels of knowledge affect everything from information gathering to product evaluation to product choice.

Much less is known, however, about the nature of the knowledge itself and how it develops. That is, though we presume there are interesting differences in the knowledge possessed by an expert versus a novice consumer, we have not focused much effort on finding out what those differences might be and how they arise (see Sujan, Sujan, and Bettman 1988 for a notable exception).

What Children Can Tell Us

What can children tell us about the way knowledge changes as it develops? Can research with children give us some hints about the types of changes we should expect? What really changes with change?

Though this is a complex question, and one whose answer might be different from domain to domain, there are a number of generalizations that do emerge in the vast literature on knowledge acquisition and development in children. To provide a concrete base of reference, let me begin by giving an example of how researchers have described knowledge development in one specific domain, specifically economic exchange.

The most inclusive description in this area is provided by two Italian psychologists, Anna Berti and Anna Bombi, in a 1988 book, The Child’s Construction of Economics. They gave children a number of questions and tasks designed to tap their knowledge of the role of money in buying and selling objects. Children’s responses were reflective of several levels of understanding, as follows: [The description of Berti and Bombi's levels is based on material from Karsten (1996).]

Level 0: No Understanding of Money. Children do not have a clear idea that money is necessary for the exchange of goods. Coins and bills are simply objects.

Level 1: Money is Used to Buy Something. Children understand that money is a necessary part of buying and selling, but do not understand why. They do not understand why people get "change" as part of the buying process and believe that change is given out indiscriminately, regardless of how much money is offered in exchange.

Level 2: Not Every Kind of Money Buys Everything. Children begin to understand the value of money at this point. They know that some coins are worth more than others, though the exact relationship is unclear and sometimes intransitive. A child may say a dime is worth more than a penny, but may reverse the ordering just a short time later.

Level 3: Some Money Buys More than Others. Children recognize that certain types of money are worth more than others, and that these higher valuations allow one to buy more-costly goods. However, the criteria used to decide the value of money is usually tied to its physical size. For example, children at this level usually believe that a nickel is worth more than a dime because it’s larger.

Level 4: Strict Money-Object Correspondence. Children at this level understand money values and prices. Their ideas of exchange are still developing, though. For example, children will say that it is necessary to pay for goods with the exact amount of money, no more and no less. They might deny the possibility that a $2 item could be purchased with a $5 dollar bill. The concept of change is still not well understood, even though children have the basic math skills to calculate change amounts.

Level 5: "Correct" Ideas. Children finally understand money valuation, the relation of money values to prices, and how change works to balance the transaction. They understand, for the first time, that one can pay more than an item costs and receive the difference in change.

What do we learn by looking at knowledge development in this domain? Well, practically speaking, those of us with children probably understand, maybe for the first time, why our children do not understand the value of money and why they continually ask us for expensive toys and clothes. It should be obvious why all of our admonitions, such as "Money doesn’t grow on trees," fall on deaf ears.

Beyond this, our picture of children’s growing knowledge base illustrates several characteristics of knowledge development found across domains. First, the changes that occur are both qualitative as well as quantitative in nature. In our example, one sees changes of a quantitative nature as children learn to recognize more coin values over time (e.g., a nickel, dime, and quarter). One also sees changes that are more qualitative in nature. For example, the transition from viewing money as simply another object to viewing it as having economic value represents a qualitative shift in the child’s way of thinking.

Second, the changes that occur in knowledge development are both abrupt as well as gradual. Though we tend to think of development as a radual accretion, many knowledge bases emerge as a function of very abrupt changes in thinking as well as gradual ones. In our example, we see gradual developments in children’s understanding of "change" as a mechanism for balancing transactions. In fact, a true understanding of this concept does not emerge until the last level. But, we also see abrupt development, as illustrated by the transition from viewing money as an object to viewing it as having economic value.

Third, knowledge development consists of changes that are both modular as well as systemic in nature. By modular, I am referring to the fact that some changes seem to occur in isolation and have little influence on other changes that are occurring. In our example, a change in the ability to recognize coin values is more modular in its effect. It takes quite a while for children to sort out the fact that dimes are worth more than nickels, but this lag in understanding does not necessarily inhibit the child’s ability to develop a more advanced notion of buying transactions. In contrast, changes in children’s thinking that allow them to understand that some coins are worth more than others, whatever the value, are more systemic in nature. That is, these changes are necessary for other changes in children’s thinking to occur, such as the concept of giving change as a way to balance the amount of money tendered with the cost of the item.

Fourth, and perhaps most interesting, is the notion that knowledge development is often accompanied by changes that are both regressive as well as progressive. Usually, we think of knowledge development as a process that results in progressively more advanced ways of thinking. In our example, there are a number of components related to children’s knowledge of economic exchange that conform to this view. However, we also see evidence of developmental changes of a regressive nature. Consider how children’s understanding of "change" comes about. At lower levels, children erroneously believe that change is given out as part of every transaction, and that the amount is given out indiscriminately. One might expect that children would start out from this base and develop more advanced notions that sometimes change is given and sometimes it is not. But, this is not what happens. Before they reach this more advanced notion of change, they go through a stage where they often insist that items can only be purchased if the exact amount of money is tendered, actually denying that change plays a role in transactions. Children actually regress, in a sense, before they advance toward a more mature understanding. [An interesting example of regressive and progressive change can be found in a recent conceptualization of change in the context of addictive behavior (Prochaska, DiClemente, and Norcross 1992).]

What We Can Learn

What can we learn from this picture of knowledge development? As a beginning, these characteristics of development can serve as guideposts for the types of changes we may find in consumers as they become more knowledgeable and develop more expertise. There is every reason to suspect, as some recent research in problem solving suggests, that the pattern of development in adults has many parallels with that of children (Kuhn 1995). We can take advantage of these parallels as we attempt to describe consumer knowledge development in more detail.

EXPLAINING KNOWLEDGE DEVELOPMENT

What We Know

If we admit to knowing very little about the nature of consumer knowledge development, we also have to own up to the fact that we know even less about the process that drives such development. Clearly, understanding the process is as important as understanding the types of changes that occur as consumers become more knowledgeable and more expert.

What Can Children Tell Us

What can children tell us about the way knowledge develops as one becomes more advanced or more expert? Can research with children give us some hints about the type of process we should expect?

Once again, I am compelled to say that this is a complex topic with relatively few simple answers. If there is any question that dominates research with children, this is it. There simply isn’t a more compelling question than how knowledge is acquired, transformed, and structured. Instead of providing an overview of the long and lengthy history of process explanations in the literature, I would like to focus on relatively new ways of thinking about the process of knowledge development, contrasting these approaches with the more traditional view.

The Staircase Metaphor. The most traditional view of knowledge development is that children progress through a series of stages in acquiring new skills and concepts. Think of it as a staircase, with children climbing up a series of steps, each representing more advanced thinking. Once a child has climbed up to a particular step, they never climb back down to less advanced ones.

This traditional view is most closely associated with Jean Piaget’s theory of cognitive development, which views development as a series of dramatic qualitative shifts that occur in children’s thinking. The most well-known feature of his theory is the depiction of four qualitatively different stages (or steps) of development: sensorimotor, preoperational, concrete operational, and formal operational. These stages are characterized by different underlying mental structures, which drive the way children think and reason across domains. A child in the preoperational stage, for example, is very egocentric in viewing the world, whereas a child in the concrete operational stage can represent other people’s points of view (for a full description, see Ginsburg and Opper 1988).

Stage theories, such as Piaget’s, do quite a remarkable job of explaining why there are regularities in the way children of a particular age think and reason across domains. Consider, for example, the development of number conservation in children. One test of this concept involves showing children a row of buttons spaced evenly apart. The experimenter then removes one button, and spreads out the remaining ones so that the length of the row is the same as before. Young children, under the age of 8, will typically say that the new arrangement has the same number of buttons as the old arrangement, even though one button has been removed. They judge number by using "length" as cue, rather than encoding other features of the display that would point to the correct answer.

We see this same pattern repeated in other domains. Moral judgments are a good example. In testing children’s concepts in this domain, researchers present several scenarios to the child, each describing an unfortunate incident that has occurred, such as a child breaking a teacup. In one scenario, the child has broken the cup entirely by accident, shattering it into a million pieces. In a second scenario, the child has only chipped the cup, which can be repaired easily, but did so because he was trying to steal cookies from a plate sitting nearby. When asked which of these children is the most "naughty," young children say it is the child who totally shattered the teacup, even though this was a "true" accident. This outcome obtains because, once again, the child is encoding and using a single cue, the consequences of the behavior, rather than other, more important, cues such as the individual’s motives.

As important as these regularities are, both across children and across domains, researchers have managed to find a host of situations that defy description in terms of the staircase metaphor. Though these are too numerous to survey, let me point out two of the most important anomalies. First, there are instances where children show different levels of understanding in very similar domains. Second, there are instances where children show different levels of understanding on the very same task from day to day.

Of course, this type of behavior drives every parent crazy! Your child acts mature and responsible one day, and turns into a "terrible-two" the next day. You can take heart in the fact that it not only drives us crazy, but it also drives researchers in cognitive development crazy, too. Crazy enough, in fact, to develop new theories and new metaphors for knowledge development. I would like to share the ideas behind two of these new theories, both quite new and provocative.

The Workshop Metaphor. The workshop metaphor illustrates the basic tenents of dynamic systems theory. Dynamic systems theory suggests that knowledge develops as the result of an interaction between independently developing subsystems. Each subsystem, or component, has its own unique course of development. Subsystems develop at different rates, at different times, in different children. For example, applying these notions to children’s knowledge of economic exchange, we would say that progress from one level to the next is a function of developing and interacting subsystems. These subsystems might be related to children’s understanding of coin values, trading, and concepts such as "more" and "less" (see Karsten 1996).

Dynamic systems theory offers the idea that children construct solutions and knowledge based on the subsystems of knowledge they have, in whatever form they have them. In other words, using a workshop metaphor, children pull tools from their mental toolkit to solve a problem or construct an interpretation of their environment. [The emphasis on construction is similar to recent views of constructed preferences (e.g., Slovic 1995) and decision-making strategies (e.g., Payne, Bettman, and Johnson 1993).] The combined condition of the tools they use influences the result of their efforts, which may be inhibited by the existence of an immature or poorly-developed tool.

These ideas are nicely captured in a passage from a recent book, How Children Discover New Strategies (Siegler and Jenkins 1989, p. 1):

"A child’s mind is like a workshop. This workshop contains a remarkable collection of materials (knowledge) and tools (learning processes) that can be used to make new products (rules, strategies, hypotheses, schema, causal networks, etc). Some of the tools and materials are useful for a great many tasks. Many others are specialized for a particular purpose, but are invaluable when they are needed.

Orders constantly arrive at the workshop for products that need to be made. Most of the requested products are familiar, and the child already knows how to make them. Others are new, though. Choosing the tools and materials for building these new products can be frustrating, but it also challenges the workshop to produce its finest wares.

Many products that are fabricated in the process of meeting one order themselves become materials and tools for making additional products. For this reason, the broader the range of products the workshop has produced in the past, the greater its potential for meeting future demands."

As this passage suggests, the workshop metaphor differs from the traditional staircase view in several important respects. First, it allows for variance across children at a particular age by proposing that not all children at that age will possess the same subsystems at the same level of maturity. Though there may be strong age-related trends in the nature of the subsystems, one seven-year-old may differ from another because one of the important subsystems is a bit more mature or more accessible for one of the children. Second, it allows for variance in children across settings by proposing that not all subsystems will be recruited in the same manner on every task. Though certain tasks may suggest the need to recruit some tools more han others, the possibility exists that a particular tool may be missing as children attempt to complete a particular task. Thus, the difference in one component or subsystem can totally change the type of knowledge or understanding exhibited by a child from one task to another.

The Wave Metaphor. The notion that a child’s knowledge can look so very different on different occasions is at the center of the newest metaphor, the wave metaphor, recently advanced by Robert Siegler in a new book, Beyond the Immaculate Transition: Change Processes in Children’s Thinking. Siegler argues that the traditional stage or staircase model is too rigid and fails to account for much of the complexity we see in cognitive development. Instead of viewing development as a progression of steps or stairs, Siegler proposes that we think about development as a series of overlapping waves, where each "wave" represents the ebb and flow of ideas and strategies. Instead of viewing development as new material replacing the old, the notion of a wave suggests that the replacement is more gradual, as the use of old concepts or strategies fades and the use of new concepts and strategies gradually builds to a crest and overtakes the old ones.

This metaphor is a particularly apt one for procedural knowledge development in problem-solving or decision making. Consider, for example, research on the development of arithmetic skills in children. Much of this literature addresses the strategies that children use for solving single-digit addition problems, such as "1 + 2," "4 + 5," and "6 + 8." Though you may not remember from your childhood, there are a number of ways to add single-digit numbers. A favorite one of preschoolers is to count out the first addend on the fingers of the left hand, count out the second addend on the fingers of the right hand, and then count all the fingers on both hands. For example, to add "5 + 2," one would count 5 fingers on the left hand, 2 fingers on the right hand, and then count the fingers on both hands to arrive at the number "7." This is referred to as a "sum" strategy in the literature.

While this works well for many basic problems, there are shortcuts that children learn by kindergarten or first grade for solving these problems. Referred to as the "min" strategy, children select the largest addend and then count upwards by the number of times indicated by the smaller addend. For example, to add "5 + 2," a child would start at 5 and count upward 2 counts ("5, 6, 7"). The min strategy produces faster response times, as well as being very useful when the addends are larger than the number of digits on one’s hands or toes!

Until recently, researchers viewed the development of strategies for single-digit addition as a sequential process, with children progressing from the use of a relatively simple "sum" strategy as a preschooler to the use of the more advanced "min" strategy as a kindergartner or first grader. That is, children were viewed as progressing from strategy A to Strategy B to Strategy C, giving up the use of an old "inferior" strategy as soon as they discovered a better one. Thus, development was characterized as a series of stages, consistent with the staircase metaphor.

Current developments have uncovered a more complex picture of how arithmetic skills develop in children. Specifically, studies in this area (e.g., Siegler 1987; Siegler and Shrager 1984), have revealed that children simultaneously use a variety of strategies to solve single-digit addition problems, including a mix of rather primitive and advanced strategies. On a single day, a child might use a "sum" strategy on one problem and a "min" strategy on another. Or, he might use these two strategies to solve the same problem on different days. What changes over time, as children become more knowledgeable, is the relative frequency of using different strategies. As children move from preschool to first grade, use of the sum strategy declines, while use of the min strategy increases. That is, knowledge development is not an abrupt shit from one type of strategy to another, but a gradual shift from a reliance on less-sophisticated strategies to more advanced ones over time. Development is really more wave-like than step-like.

The wave metaphor differs from the traditional staircase view in several important respects. First, it allows for variance across children at a particular age by proposing that not all children will be riding the same wave, or that the wave may be at different levels of cresting or falling. Though there may be strong age-related trends in the existence of particular waves (strategies), one seven-year-old may differ from another because the wave is just cresting for one, but is falling for the other. Second, it allows for variance in children across different settings by proposing that children do not ride only one wave, but have several in motion at any one time. Though certain waves (strategies) may be more favored, the possibility exists that a child may choose to ride quite a different wave at any one point in time.

What We Can Learn

Taken together, what can we learn from these metaphors? How can we apply the workshop and wave metaphors to deepen our understanding of consumer knowledge development and inform our research?

As a beginning, let me suggest two very concrete ways that we can use the ideas behind these metaphors in our research. First, if knowledge does not develop in invariant stages, but develops in a more constructive and wave-like manner, we need to employ different data collection methods. Specifically, instead of measuring consumer knowledge or strategies at one point in time, we will need to assess them at multiple points in time. Using such approaches, called microgenetic methods (cf., Kuhn 1995), is one of the few ways of capturing anything other than a strict stage-like progression of knowledge development.

Second, continuing with this theme, we need to employ different data analysis methods. Our current methods, based upon analyses of group means, hide much of the variance that is the very focus of the workshop and wave metaphors. If the process of development is not stage-like, it will be hard to detect if we do not search for the possibility that differences exist among groups of consumers we wish to label "experts" or "novices." The metaphors I have described encourage us to look beyond what is happening at a group level and consider what the within-group variance can tell us about how consumer knowledge or strategies are developing.

CONCLUDING COMMENTS

Whether you realize it or not, you have broken out of the adult box for the last 30 minutes. I have not discussed even one adult study, based on one adult theory, about one adult consumer. Hopefully, you’ve found some of the ideas and concepts interesting.

My objective today has been to convince you to break out of the adult box to see what child development research has to offer. By necessity, I narrowed the discussion of relevant research to one topic, knowledge development, but be assured that others could be equally interesting. For example, if you are interested in consumption symbolism, you might find studies of adolescent gang behavior to offer some very important insights. If you are interested in ethics or consumer misbehavior, you might find the literature on children’s moral judgments to offer some interesting direction.

Children do have something to tell us...if only we are willing to listen. Follow the example of scholars who have used research in child development to enrich their thinking, regardless of whether they are studying adults or children. Consider Greg Murphy and Doug Medin, two prominent cognitive psychologists. In their frequently-cited 1985 article titled "The Role of Theories in Conceptual Coherence," Murphy and Medin arge that individuals have "theories" about how objects "hang together" (Murphy and Medin 1985). If you read this article carefully, you will note that much of the empirical support they marshal for their ideas comes from the concept development literature in child psychology.

This is, by no means, an isolated example. In their 1993 book titled The Adaptive Decision Maker, John Payne, Jim Bettman, and Eric Johnson reference work on children’s problem-solving abilities in their discussion of why individuals sometimes fail to adapt. In their recent article titled "The Persuasion Knowledge Model: How People Cope with Persuasion Attempts," Marian Friestad and Peter Wright incorporate ideas pertaining to children’s developing cognitive and social abilities in their discussion of how persuasion knowledge develops (Friestad and Wright 1994). As a final example, Joe Alba and Wes Hutchinson incorporate literature on analytic and holistic classification in children in their well-known 1987 article titled "Dimensions of Consumer Expertise" (Alba and Hutchinson 1987).

Let me suggest that you can go even further than this if you are willing to spend more time out of the adult box. Even if your research agenda finds you squarely in the adult domain, you may find interesting extensions of your research by studying similar phenomena with children. Some of your colleagues have done so, such as Russ Belk, Merrie Brucks, Kim Corfman, Terry Shimp, Mita Sujan, and more. You need not spend most of your time outside the adult box, though you are also welcome to do so. Some of us-such as Marv Goldberg, Gerry Gorn, Carole Macklin, Laura Perrachio and myself-go back and forth between boxes quite happily.

Whatever your course, I hope you’ll remember the notion of the adult box and will think about breaking it out of it, at least every now and then. Children do have something to tell us...I hope you’ll keep listening!

ACKNOWLEDGEMENTS

I would like to thank Sara John and Tessa Druley for providing the illustrations that accompanied my address. I would also like to acknowledge the many helpful comments received on a previous version of the address from Jim Bettman, Marv Goldberg, Jennifer Gregan-Paxton, Carole Macklin, Laura Peracchio, Terry Shimp, and Alice Tybout.

REFERENCES

Alba, Joseph W. and J. Wesley Hutchinson (1987), "Dimensions of Consumer Expertise," Journal of Consumer Research, 13 (March), 411-454.

Berti, Anna and Anna Bombi (1988), The Child’s Construction of Economics, New York: Cambridge University Press.

Friestad, Marian and Peter Wright (1994), "The Persuasion Knowledge Model: How People Cope with Persuasion Attempts," Journal of Consumer Research, 21 (June), 1-31.

Ginsburg, Herbert P. and Sylvia Opper (1988), Piaget’s Theory of Intellectual Development, Third Edition, Englewood Cliffs, New Jersey: Prentice-Hall.

Karsten, Yvonne Cariveau (1996), "A Dynamic Systems Approach to the Development of Consumer Knowledge: Children’s Understanding of Monetary Exchange," Unpublished Doctoral Dissertation, University of Minnesota.

Kuhn, Deanna (1995), "Microgenetic Study of Change: What Has It Told Us?" Psychological Science, 6 (May), 133-139.

Murphy, Gregory L. and Douglas L. Medin (1985), "The Role of Theories in Conceptual Coherence," Psychological Review, 92 (July), 289-316.

Payne, John W., James R. Bettman, and Eric J. Johnson (1993), The Adaptive Decision Maker, Cambridge: Cambridge University Press.

Prochaska, James O., Carlo C. DiClemente, and John C. Norcross (1992), "In Search of How People Change: Applications to Addictive Behaviors," American Psychologist, 47 (September), 1102-1114.

Siegler, Robert S. (1996), Beyond the Immaculate Transition: Change Processes in Children’s Thinking, NY: Oxford University Press.

Siegler, Robert S. and Eric Jenkins (1989), How Children Discover New Strategies, Hillsdale, New Jersey: Lawrence Erlbaum Associates.

Siegler, Robert S. and J. Shrager (1984), "A Model of Strategy Choice," in Origins of Cognitive Skills, C. Sophian (Ed.), Hillsdale, New Jersey: Lawrence Erlbaum Associates, 229-293.

Slovic, Paul (1995), "The Construction of Preference," American Psychologist, 50 (May), 364-371.

Sujan, Harish, Mita Sujan, and James R. Bettman (1988), "Knowledge Structure Differences Between More Effective and Less Effective Salespeople," Journal of Marketing Research, 25 (February), 81-86.

----------------------------------------