Fall 2001 Abstract Algebra

Questions and comments welcome!  Email me at fnewberg@csulb.edu.
http://www.csulb.edu/~fnewberg

Goals, Assessment and Course Materials.

Exams and supporting materials are provided below.  This is a senior level algebra course required for all pure math majors, including those planning to teach high school.  We do not offer a second semester of abstract algebra at the undergraduate level, though from time to time advanced undergraduates continue on to take our graduate algebra course.

I always lectured the entire class period, which lasted one hour and fifteen minutes and met twice weekly.  I had 34 students. Of these, 2 students dropped, there were 1 F, 3 D's, 10 C's, 7 B's and 11 A's (1 of which was a B students that received a high A on the final exam).   My colleges informed me that 6 of those 11 students are the strongest this department has seen in years, that I was lucky to have them, and not to expect so many A's in general.
 

Goals

Very generally, the nature of mathematics requires that the primary goals are to teach some of the basic vocabulary in some of the basic fields of mathematics and to develop proficiency in reasoning and communicating using the precise language of mathematics.  These are the goals of this course as well; on one hand there is the content, and on the other the reasoning and communication skills.

Content:
I planned to spend and spent the first third of the semester discussing the integers and basic number theory, the next half semester on group theory, and the final sixth on rings and fields.  I covered Lagrange's Theorem and cosets, though not to the group structure on quotient groups. I did homomorphisms and isomorphisms thoroughly and the First Isomorphism Theorem, though since we did not have a group structure on the quotient, we just showed the bijection between the cosets of the kernel and the image of a homomorphism.  We covered the definition and various examples of rings (commutative and noncommutative), integral domains, division rings and fields, as well as ring homomorphisms.

Next time:  I will cut the number theory part by half and begin group theory seriously by the second sixth of the semester.  I used the number theory because I wanted to get them off to a good start with easier problems (and I wanted to use the number theory freely later on), but I would like to try to give the same writing and reasoning instruction through the group theory in order to get through more content.  I hope to add the group structure on quotient groups and the rest of the isomorphism theorem, without losing any of the topics listed above.

Reasoning and communication:

Next time:  These continue to be my goals in this course.
 
 

Assessment

Homework:
All personal interaction I had with the students was through their written work and office hours.  The homework was therefore extremely important and counted for 40% of the students' overall course grades.  I assigned at least one proof each class period due the next period, and most of the time graded each day's papers by the next class period.   I used the constant exchange of homework to pass information to the students about their grades and other logistics.

Grading:  The assignments were graded subject to the following rules:

Upshot: The students all rewrote virtually all of the homework assignments as needed, giving them an excellent resource to prepare for their exams.  They read the comments I wrote on their papers because they needed to do so in order to rewrite them.  Their writing became more consistent and coherent through revision and critique.  I spent a lot of time grading papers.

Next time:  I used this grading scheme in a sophomore-level bridge course at Penn State (4 sections in 3 consecutive semesters) and will use some variation of it in all "proofs" courses, as long as I have time; there is a lot of grading time, but it is so effective, that I find it worthwhile.

Accommodating a variety of levels of student preparation:  From time to time, I assigned two sets of problems, one labeled Fundamental and the other labeled Challenging, letting the students choose which problems to complete (for example, they were asked to do 2 of 4 problems, with two labeled Fundamental and two labeled Challenging).  The Fundamental problems were always straight forward applications of the definitions and theorems given, though they were not always easy.  The students were told that they would be held responsible for the Fundamental problems on the exams.  The Challenging problems required mathematical ideas beyond the definitions and theorems of the section, and often required a trick that I did not want to explain over and over in my office hours to students still struggling with the definitions.  In messages on their homework, I encouraged approximately the top third of my students to do the Challenging problems, indicating that I expected them to do so; many of these students did not consider themselves strong students, and I hoped that they would rise to the challenge.  Orally, I encouraged everyone to try all problems.

Upshot:  About a fifth of the students always did the challenging problems (sometimes getting help from other professors).  Maybe another fifth did the Fundamental problems, but came to ask for solutions to the Challenging problems because they had tried and failed to solve them.  I believe it kept my advanced students engaged, and gave me a way to teach them a little deeper into algebra without losing the weak ones.

Next time:  I think I did this only on about 4 assignments.  Next time, I plan to try to do it much more frequently, maybe once per week, depending on the students.  Last time I started this about a month into the course, after the wide range of preparation that the students had became apparent.  Next time, I may start it earlier so that I can push my strongest students a little farther.

Exams:
I provided a study guide one week before each exam.  On it I gave the students a list of theorems and definitions followed by a break down of the exam.  The breakdown was always essentially the following.

I sometimes gave them more information about the content in the last part, for example, I told them on the second exam that they would be asked to show a given binary operation is a group, and that a given subset of a group is a subgroup.  Please refer to the review sheets and exams below for more examples.

Upshot:  On the exams, I often asked for a definition followed by a problem using that definition. My thought was that I was forcing them to receive the partial credit for the problem by knowing the definitions.  Students writing definitions out when fishing for partial credit clutters any attempt at a solution; this was my attempt to avoid that clutter.   I gave a couple of quizzes over definitions (worth little) before the first exam, so that when I told them to memorize the definitions for the exam, they believed me.  This was effective in motivating the students to learn the definitions and well as emphasize the importance of precise language in mathematics. Most students received all the credit for this part of the exams.  The 10% of the exam attributed to a new definition had much the desired effect.  On the first exam most students did not receive even half credit on this part.  A few students with lower grades did complete this section, and I made an effort to help those students individually to understand how to use their apparent reasoning skills to solve other problems.  In one rewarding case, a student who received a low B but solved that part of the exam responded to my prodding and shot to the top of the class, getting a nearly perfect score on the final.  On the second exam about two thirds of the students got at least 7 out of the 10% on that problem, and on the final, as a group they clearly approached it as one of the easier problems. (One student remarked, "Well, it can't be that hard since it is totally new.")

Next time:  I plan to structure my exams in this way again next semester, though I am considering changing the 40% to 35% and putting 5% more weight on the students general knowledge (the section worth 50%).
 

Course Materials

The following are the course materials from my 2001 abstract algebra course.  If you are a student in my 2002 course, be wary; I have made some changes to the content for this semester, and the exams here are not likely to be over the same material as in the 2002 course. Questions and comments welcome!  Email me at fnewberg@csulb.edu.
http://www.csulb.edu/~fnewberg