Topics covered: Course Introduction
Instructor: Prof. Donald Sadoway
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So 3.091 is a subject, it's one of three that satisfies the Institute undergraduate chemistry requirement. And it sets itself apart of the other two. The other two are both taught by the Chemistry Department and follow in the tradition of general chemistry classes as students would have expected to met them. 3.091 is taught by the Department of Material Science and Engineering. So, as the name implies, it focuses more on the solid state. And it does so for good reason. Most engineering systems are made of solids. For example, what kinds of topics are in 3.091 that otherwise you might not expect to find in a first year general chemistry class?
Well, we talk about structure of solids, crystal structure and the characterization of crystal structure by x-ray diffraction. So generation of x-rays, the use of x-rays in determining the long-range order or lack thereof in a solid. We look at metals, we look at ionic solids. We look at them amorphous solids. Silicate glasses. We look at polymers, another example of amorphous solids. And then, ultimately, we look at the pinnacle of macromolecular design which is biochemistry and with DNA which is nothing more than a polymer. You know, if you some day start thinking that you are really special, just remember that the peptide bond in a protein is identical in composition to the amide bond in nylon rope.
So a little bit of humility is probably in order here. Evaluation methods, there are some strong similarities to what you would expect in a large class. I mean this class, in recent years, has numbered some 600 students. So we have exams. We have monthly exams that are written during the normal class time. It is a 50 minute test. I refer to exams as celebrations of learning where we get together and show each other what we have mastered. So it is a festive occasion. And the idea is to attempt to measure what they have learned in the light of what I have taught. It is not an IQ test. It is not to try to beat them down and prove to them that I am the professor and I know more than they do, but rather to give them feedback.
And I like to think of three bins. OK. One bin is at the end of 50 minute I should be able to ask them three or four questions that they should comfortably be able to finish in the time allotted and give me enough information to allow me to decide whether keep up the good work, you've mastered the material and that is my message. Second bin is you are not mastering the material. This is not about you.
It is not telling you that you are a bad person or that you don't have the intellectual apparatus to be here. It is telling you whatever you are doing it is not working and let's figure out a way to make you successful. And then the third bin is the student is probably smarter than I am and I don't have to worry about this student, but I ought to tell the student, you know, you are doing really, really well and it is a pleasure to have you in the class. So those are my three bins. And then there is a final exam.
It is a three hour final which is both cumulative and specific to the subject matter at the end of the semester. In addition, homework. And many of the subjects here at MIT it comes in waves weekly. Large problem sets, they are called, that are due on a weekly basis. They are submitted for grading. I don't do this. I give out problems with model solutions at the beginning of a unit. And the students are given all of the answers to the questions. And instead of having them submit something for grading, once a week we have a ten minute quiz based upon the content of the weekly homework. So if you have done the weekly homework and mastered the material you should have no problem. The monthly tests are returned within 24 hours.
If the students write them on a Wednesday they get them back in recitation on a Thursday. I believe in giving rapid feedback. The students have worked hard. They are ready to see to what extent they have mastered the material. And I want to tell them right away either keep up the good work or get in and see us because we need to change your ways. And then with the weekly tests it is the same thing. The students will write them on a Tuesday. And I require of my recitation instructors that those quizzes be graded and returned on the Thursday.
So there is never a lag in getting the message back to the student to make sure that the student is given the necessary information to decide how to go about investing in the subject. The instruction comes in several modes. There are the lectures with the large group Monday, Wednesday, Friday. And these are fairly classical. I stand at the front of the class wired for sound. I write on the board. I still use chalk on a blackboard. And I augment with audiovisual imagery, sound through a laptop computer that is projected on screens. I believe that it is good to not put everything on the computer. I think there are different cognitive modes that are activated by my speaking, my turning and writing on the board. And they see the writing, they copy the writing and so on.
And then the lectures are recorded and then posted subsequently for students to view, should they choose. And also for OCW, of course, to post for anybody who wishes to view. So all of this is available to them. Then twice a week they are in small groups of about 20 with a recitation instructor. That recitation instructor could be a graduate student TA. Could be a faculty member, sometimes junior, sometimes senior faculty member, sometimes an upperclassman. So it is in the recitation setting that the students get the chance to ask questions, go over problems, go over lecture material and so on. So that is the mode of instruction.
