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Why not just use questions provided in textbooks, instead of these worksheets?


Short answer:

Typical questions provided in textbooks are written quite differently from most of the questions in these worksheets, and are intended for a different purpose.


Long answer:

Open up any electronics textbook and take a close look at the answers to end-of-chapter questions. What do you see? Mostly numbers, with an occasional graph or diagram. Although many in quantity, they all have pretty much the same, narrow, quantitative focus. Questions like this are good for "drill," where students practice to develop proficiency at using math. However, they typically do not challenge students to explore the conceptual details of electronics, or relate theory to real-life practice. And they rarely, if ever, begin with the word "Why."

Scientific practice, whether it be pure research, engineering, or even technician-level work, involves inductive reasoning as well as deductive. It is not sufficient for a student to simply "drill" on using general formulae and theory to deduce specific answers to specific questions. Students must also become adept at drawing their own general conclusions from specific instances. I say this because inductive thinking is the key to autonomous learning, which is a vital skill.

These worksheets are not just collections of practice problems with definite, concrete answers. Rather, they are designed to make the student think about why circuits function as they do, and how realistic problems are solved. You will notice that many of my questions contain either the word "why," or the word "explain," and for good reason. These types of questions ask the student to abstract from specific details, facts, and figures, to the reasons behind those details, facts, and figures. This is exactly what students will have to do after graduation when they encounter something they don't understand: abstract from specific data to general principles, or at the very least relate specific data they encounter to general principles learned long ago in school.

The types of questions I write are also designed with follow-up discussion in mind. I especially like questions with multiple correct answers, and questions whose answers depend heavily on unstated assumptions, because these simulate the complexities of real life for the learning benefit of the students. How many textbook questions support multiple correct answers, force the reader to question assumptions, or even suggest the possibility of creative solutions?

Why are typical textbook questions so one-dimensional? One possible reason is that textbook prose and illustration demands an immense amount of effort to create, and so the questions accompanying each chapter tend not to be the focus of the author's effort. Also, it is a lot easier to generate numerical answers for deductive questions than it is to write non-quantitative answers to inductive or loose-ended questions. This is especially true with modern circuit simulation software, where it is possible to have a computer provide answers for you.

I vastly prefer to let instructors and students invent their own quantitative problems to solve, and then obtain the answers to those problems by building real circuits and measuring the results, and/or by running computer simulations. With inexpensive electronic components, test equipment, and simulation software being so readily available, it seems silly to me for textbook authors and instructors to waste time calculating answers for sample circuit problems. Rather, teach the students how to obtain their own answers through experimentation and simulation (and eventually, how to challenge themselves with problems of their own design!), and they will be much better prepared as a result.

In recent years I have seen a disturbing trend in textbook questions. Many new textbooks have section reference numbers shown next to each question, to show the student where they need to read in the book for the method of solution. In trying to be "friendlier" to the student, authors and publishers bypass a very important step in learning: how to research information. I can't tell you how many times I've had students approach me, puzzled by a problem, when the answer they seek is just a paragraph or two away from where they are in a book. This is the type of student who would really like to have references next to each question to tell them where to read. But references don't address the root problem: the student's inability to seek and filter information on their own. In fact, references that tell the student where to read actually make the root problem worse, because now students become accustomed to having others do the work of research for them. What first appears as a convenience will, over time, be viewed as an entitlement.

This is certainly the trend I've noticed as an instructor when giving verbal answers to students: if you directly answer every question a student approaches you with, over time the student begins to expect it, and will complain if you later direct him or her to research something on their own. This does nothing to prepare them for the challenges of real life, and in fact does quite the opposite.


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