Even when students ’ prior knowledge is accurate and activated, it may not be suffi cient to support subsequent learning or a desired level of performance. Indeed, when students possess some relevant knowledge, it can lead both students and instructors to assume that students are better prepared than they truly are for a particular task or level of instruction.
In fact, there are many different types of knowledge, as evidenced by a number of typologies of knowledge (for example, Anderson & Krathwohl, 2001 ; Anderson, 1983 ; Alexander, Schallert, & Hare, 1991 ; DeJong & Ferguson - Hessler, 1996 ). One kind of knowledge that appears across many of these typologies is declarative knowledge , or the knowledge of facts and concepts that can be stated or declared. Declarative knowledge can be thought of as “ knowing what. ” The ability to name the parts of the circulatory system, describe the characteristics of hunter - gatherer social structure, or explain Newton ’ s Third Law are examples of declarative knowledge. A second type of knowledge is often referred to as procedural knowledge , because it involves knowing how and knowing when to apply various procedures, methods, theories, styles, or approaches. The ability to calculate integrals, draw with 3 - D perspective, and calibrate lab equipment — as well as the knowledge of when these skills are and are not applicable — fall into the category of procedural knowledge.
Declarative and procedural knowledge are not the same, nor do they enable the same kinds of performance. It is common, for instance, for students to know facts and concepts but not know how or when to apply them. In fact, research on science learning demonstrates that even when students can state scientifi c facts (for example, “ Force equals mass times acceleration ” ), they are often weak at applying those facts to solve problems, interpret data, and draw conclusions (Clement, 1982 ). We see this problem clearly in Professor Won ’ s class. Her students know what various statistical tests are, but this knowledge is insuffi cient for the task Professor Won has assigned, which requires them to select appropriate tests for a given data set, execute the statistical tests properly, and interpret the results. Similarly, studies have shown that students can often perform procedural tasks without being able to articulate a clear understanding of what they are doing or why (Berry & Broadbent, 1988 ; Reber & Kotovsky, 1997 ; Sun, Merrill, & Peterson, 2001 ). For example, business students may be able to apply formulas to solve fi nance problems but not to explain their logic or the principles underlying their solutions. Similarly, design students may know how to execute a particular design without being able to explain or justify the choices they have made. These students may have suffi cient procedural knowledge to function effectively in specifi c contexts, yet lack the declarative knowledge of deep features and principles that would allow them both to adapt to different contexts (see discussion of transfer in Chapter Three) and explain themselves to others.
Implications of This Research
Because knowing what is a very different kind of knowledge than knowing how or knowing when , it is especially important that, as instructors, we are clear in our own minds about the knowledge requirements of different tasks and that we not assume that because our students have one kind of knowledge that they have another. Instead, it is critical to assess both the amount and nature of students ’ prior knowledge so that we can design our instruction appropriately.
