# Gas station without pumps

## 2013 April 30

### UC Berkeley college tour

Filed under: home school — gasstationwithoutpumps @ 22:05
Tags: , , , , , ,

My son and I went on a prospective-students’ tour of UC Berkeley today.  Because the information session and tour was scheduled very early in the day (starting at 9 a.m.), and public transit from Santa Cruz to Berkeley is slow (about 3–3.5 hours, using 3 different transit systems), we actually left last night, shortly after my early evening class ended.

We started with the 8:15 p.m. SCMTD Highway 17 Express bus over the hill for $5. It’s a fairly comfortable bus, being a relatively new natural-gas powered bus with soft slightly reclining seats, air-conditioning on hot days, and free WiFi. We took advantage of the soft seats to nap a bit, but did not try the WiFi, having no WiFi devices with us. Then we took the VTA 181 Express from the Diridon train station to the Fremont BART station. This bus costs$4 for adults, $1.75 for children under 18, and spends a big chunk of the trip on the freeway after a couple stops in downtown San Jose. The bus was packed, apparently with San Jose State students going home from evening classes. Unfortunately, the ride was on a poorly maintained rattletrap bus with shocks that should have been replaced about 100,000 miles ago. The seats were hard, the floors dirty, and knee room close to non-existent. I’m guessing that either there is no money in Silicon Valley any more to maintain their bus fleet (or their roads) or that the money is concentrated in the hands of a few people who think that bus riders are so low-class that third-world quality is all that is needed. Perhaps VTA has been sinking all its money into expanding the light rail service and neglecting maintenance and replacement of its bus fleet. The BART train ride from Fremont to Berkeley ($4.35) was fine—the ride was fairly smooth and the cars clean, though it was clear that they were far from new.  It was a step up from the decrepit VTA bus, but not as comfortable as Caltrain or even the Highway 17 Express bus—and I usually find trains and light rail much more comfortable than buses.

Our connections were all excellent, and we got to Berkeley an hour earlier than Google Maps had suggested—the Highway 17 Express had made good time and we caught an hour earlier 181 than Google thought was possible.  (The usual schedule calls for the 181 to leave just before the Highway 17 Express arrives, since the transit agencies don’t think much about synchronizing between systems.)  We made it to our motel (Berkeley Travelodge) just over 3 hours after leaving our house, getting in before 11pm. Since the distance is 76 miles by car, we averaged about 23 mph, which is twice the speed of the public transit we took in LA.

The Travelodge had one of the smallest motel rooms we’ve stayed in (barely room for the 2 beds), and it smelled a little musty, but we slept well enough despite that.  The “continental breakfast” was also about the feeblest attempt at that we’ve seen—I had a cup of tea providing my own tea bag and a tiny sweet roll in a plastic package.  Our poor breakfast may have contributed to low blood sugar and less enthusiasm than we might have had with a decent breakfast.

In the morning we walked to Sproul Hall, the administrative building on Sproul Plaza where the information session was scheduled. The info session was so early in the day (9 a.m.) that the campus was nearly deserted as we walked across it to Sproul.  Even Sproul Plaza was nearly empty.

The only substantive advice in the whole presentation was that the student essays should focus on achievements, not just activities, and that depth and duration of an activity are more important than breadth of different activities.  This was not news to us, but it was more clearly presented than at other colleges. The depth-rather-than-breadth focus is good for his admissions chances, as my son has two activities that he has been engaged in for a long time: theater for the past 12 years, science fair for the past 8, for both of which he has positive outcomes to talk about, though no obvious super-star status.  For example, he’s never won his category at state science fair, but he has gone to state 6 years running (a distinction shared by only about a dozen students), and he did make 3rd in his category one year.  Since all his science fair projects have been in the field he plans to major in, tying them into his application should not be too difficult for him.

The tour itself had more people on it than the information session, and was fairly ably presented by the student guide. It was not as sports-focused as the University of Colorado Boulder tour—perhaps not even as much as the UCLA one, though there was more mention of traditions surrounding football games than we were really comfortable with, and the tour guide referred to the sports terms in the first person (“we won …”), even though she was not on the team herself (she did play in the band that accompanies one of the teams).  As with the UCLA tour, we did get to see the interiors of a couple of buildings (the huge Valley Life Sciences Building and the Doe Memorial Library), but no classrooms.  The interiors we were shown looked more like museum entrances or film sets than like working parts of the university.  Because the dorms are at the uphill edge of campus, they were only pointed out to use from a distance. By the end of the tour (around 11:30 a.m.), Sproul Plaza was bustling, though the tour guide had felt obliged to apologize for how dead it was at 10 a.m.

Overall the Berkeley tour was perhaps the blandest and least distinctive of the tours we’ve had—it told us almost nothing about how well the school would fit my son’s needs.

My son had tried to set up an appointment with a CS faculty member at Berkeley, but he’d left it rather late, and the faculty member had said just to stop in during his open office hours (11–12) as he had no other time today.  The trek from Sproul Hall to Soda Hall is a fairly long one (½ mile)  for such a compact campus, and when we got there the professor was in a meeting (apparently with grad students).  We waited around for about 5–10 minutes, but it didn’t look like he was going to be free, so we left without meeting him.

We looked over Soda Hall, which is a nice new building.  We noted that it seemed awfully sterile: there were no conference posters, no announcements, nothing to break up the stretches of blank wall.  The faculty offices all seemed to be tucked away in lab pods behind closed doors—we saw no welcoming open doors as at Harvey Mudd. They had a big TV screen in the main lobby flashing up research posters and unidentified pictures, but none of the posters stayed on the screen long enough to read more than the title, and the resolution was too poor to read the poster even if it had been up long enough.  It looked like a movie set of a “futuristic” computer science department, rather than a real one.  The only lab we saw was the one where we waited for the faculty member—it had a huge bullpen of cubicles for grad students, a few conference rooms and offices, and a kitchen.  It looked like a department unto itself, and I wonder whether UCB is organized into independent fiefdoms that don’t talk to each other, the way so many large departments are.

We had lunch in a courtyard just down the hill from Soda Hall, that Google Maps currently identifies as “Northside Asian Ghetto”, which I doubt is any sort of official name.  There were several Asian restaurants (Korean, Chinese, Himalayan, Japanese (udon), Japanese (donburi), Vietnamese), and lots of students and faculty eating lunch.  I suspect that it is a favored hangout for CS students, though the few textbooks I saw were not likely texts for CS students. We saw a lot of students eating in groups, but we also saw a lot sitting by themselves.

Although we did not get a chance to talk with any faculty, we did get a chance to ask some CS undergrads about the program.  It seems that the classes are even bigger than at UCLA, with 400 or more in the lower division and 100–200 in the upper division.  There is more opportunity to do research, but students have to hustle a bit to find it—some of the students admitted that they didn’t know anything about research opportunities, as they had never tried to get involved, while one had done research his freshman year but had since dropped it.

I worked in one more visit, to the theater department to find out whether non-theater-majors had any hope of getting parts in productions.  The answer was a definite “yes”—they do open casting for all productions with no slots reserved for theater majors or minors.  The acting classes are the same way, though I note that Theater 10, 11, 110A, 110B, 111 all require an audition (a 1-minute monologue) to get into, and Theater 12, 162, 163 require an interview [ http://tdps.berkeley.edu/programs-courses/courses/class-auditions/ ].  The Acting Focus minor, which consists primarily of audition entry acting classes, looks like a pretty good fit for what he wants to do with theater in college, so that part of his education could be easily met at UCB.

Overall, UCB looked like a better fit than UCLA, but not really thrilling.  Even though UCB has only about 25,000 undergrads (smaller than the undergrad university I went to), it is big enough and the faculty distracted enough by grad students and research, that it would be easy for undergrads to get lost in the shuffle if they didn’t push themselves forward.

We took the BART, VTA 181, and Highway 17 Express back home, again getting excellent connections.  The VTA 181 bus this time didn’t rattle quite as much (the shocks were not completely gone), but it stank of stale urine.  VTA really needs to work on their cleaning and maintenance problems!

We’ve got one more visit to do this Spring (Stanford), then a few more to do in September (MIT, Olin College of Engineering, maybe CMU and U Washington).  He may apply to a few others without visiting them, visiting only if admitted.

## 2013 April 29

### AP tests as validation of courses

Filed under: home school — gasstationwithoutpumps @ 09:07
Tags: , , ,

I’m on a couple of the Advanced Placement teacher mailing lists (Physics because I’ve been home-schooling my son in calculus-based physics, biology because I’ve been attempting to get bioinformatics into AP bio courses as a teaching tool).  On one of the lists, a fairly new teacher brought up a concern about grading—last year many of his or her top students got 1s on the corresponding AP exam.  This triggered an excellent discussion about the meaning of grades and the value of the AP test.  In this blog post I’m going to repeat my contributions to the discussion, lightly edited to remove any identifying info, with brief summaries of other views to show what I was responding to (often lumping several people’s ideas together).

Speaking as a college professor, one of the main values of the AP exams is providing a uniform external calibration for the level of high school classes.  Most high school teachers don’t have that much communication with other teachers, particularly not on matters like what level of performance should be expected of students at different levels.  The result has been an enormous grade inflation over the past few decades, so that “A” is the most common grade in many schools rather than a rare accolade.  (The problem is common in colleges also, perhaps even worse than in high schools, especially in the humanities.)

Having an external calibration (an A in this course is roughly the same as a 5 on the AP exam) is very useful for gauging the level of the course, for the teacher, for the students, for parents of the students, and for the colleges that might admit the student.  The AP exam scores, after all, are supposedly set to correlate with the grades the students would have gotten in a first-year course in college.  It used to be that 5, 4, and 3 correlated well with grades of A, B, and C, but grade inflation in the colleges appears to have advanced faster than on the APs, so perhaps 5 and high 4s correspond to an A, and low 4s and 3s to a B (depending on the college, of course, as grade inflation is far from uniform).

Of course, the AP test does not measure all the things that go on in an AP course, and a student can do well in the course and poorly on the exam or vice versa, but if A students in a course are consistently getting 1s on the test, it leads one to suspect that grade inflation has happened.  Similarly if C students are routinely getting 5s, one suspects that the course grading is ridiculously harsh.

Others pointed out the obvious thing, that the test is a 3-hour snapshot of how a student did on an arbitrary subset of the material on one day.  Seniors who have already been admitted to college (or decided not to attend) may have little incentive to do well, particularly if their college does not give credit for AP exams.    One teacher, who posts a lot of good stuff on the mailing list, asked me directly:

I am curious to know what portion of the grades in the courses you teach are determined by one, largely multiple choice exam?  I’ve never taken a worthwhile course where “passing” was ever determined in such a way.

He called it right on that one.  I’ve never given a multiple-choice exam in 31 years of being a professor—multiple-choice exams are very difficult to write well, and really only appropriate when there are enormous numbers of test takers to reduce the cost and variance of grading and amortize the large cost of making the exam.  For that matter, I give very few exams—most of my courses are graded on the basis of week-long or quarter-long projects, papers, and programs.  I’m not particularly interested in the things testable by multiple-choice tests (mainly memory and simple reasoning tasks), but in what students can do with a sustained effort.  My most recent course (Applied Circuits for Bioengineers) was graded mainly on the basis of their weekly design reports based on their lab work (about 5 pages of writing a week, and any mistakes in the schematics or explanations meant that they had to redo the writing).

I’m not going to defend the AP exams as great ways to evaluate learning, but they are better than the exams that most teachers write and rely on for grading, and they do have the advantage of uniformity across a large number of classrooms.  A 5 on an AP exam may not tell me a lot about a student’s capabilities, but I believe it tells me more than an A from teacher I’ve never met and who may have only taught a handful of AP students.

I agree that the goal of an AP course is not “college credit” or even “preparation for the AP exam,” but the learning that takes place.  But grades and  exams scores are used for selecting kids for college admission (as being better than a simple lottery or selection based solely on money or race), so it is better if the exams and grades are as meaningful as they can be made (at reasonable cost—a lot of state testing is providing very little useful data at enormously high cost in both money and lost time).  Because teachers have so little opportunity to calibrate their own grading, an external test at the right level provides very useful information.

I agree that a single sample of small number of students may not tell you much about the level of instruction in a class, but may be a warning that recalibration is needed. There are many possible reasons for the discrepancy (difference in content between course and exam, difference in level of expectations, student test-taking ability or attitude, random noise, …).  For a course labeled “AP”, the teacher has a responsibility to make sure that the content of the exam is covered in the course.  As a parent, I would also want the level of expectations in the course to be as high as in a first-year college course.  If the students are uniformly doing worse on the test than what the teacher expects, then some reflection on why the expectations are wrong is needed.

Elsewhere in the discussion, another teacher asked

When admissions officers are trying to select <6% of the students from 38,828 applicants (as Stanford did this year), it is difficult to process voluminous communications from individual teachers.  They rely on summary statistics (GPA and SAT scores, for example) to do crude filtering, then concentrate on student essays and letters of recommendation.  The very selective schools sometimes try to correct the GPAs based on grade inflation at the high school (there are databases of information about each high school being sold—I’ve no idea how accurate the information in the databases is, but some admissions offices use them).

The college faculty, who might care about the “skills that aren’t reportable by traditional methods”, are rarely part of the admissions decisions.

Public universities are usually forced to have a simple formula for most of their admissions, to be able to show the public that they are being scrupulously fair.  If they took into account “skills that aren’t reportable by traditional methods”, parents of rejected students would scream to their legislators to cut off funding to the university.  (An exception is always made for athletics, which is a sacred cow in the US.)

Later in the discussion, after more narrative transcripts were proposed and the value college admissions officers put on letters of recommendation had been introduced, I wrote about my experience with narrative evaluations.

I had to review narrative transcripts for honors review of graduating seniors, and I often found it very difficult to interpret the narratives.  It took a long time to read a narrative transcript, and often told me very little about the student. There was no controlled vocabulary, and the same word might be used by one instructor for a barely passing performance and by another for a truly excellent performance.  I could see why med schools could be frustrated by the difficulty of dealing with this format.  Nowadays the honors review in the school of engineering is based on GPA, with a well-defined grey region where student research projects can make a difference in the honors rating.  I understand that the honors review now takes only a fraction of the time it used to, despite large increases in the number of students reviewed, and the time is spent only on the cases where some thought is needed.

As a grad director, I read a lot of applicant files for admission to our program.  GRE scores and GPA do matter, but not very much, as the GRE tests essentially the same stuff as the SAT (nothing college level on the general GRE and there isn’t a subject GRE in our field) and college GPAs are often highly inflated, depending on the college.  We also get a lot of foreign applicants, whose grades come on a bewildering variety of different scales that are essentially uninterpretable.  We expect high GRE scores of all applicants, but decide between them based mainly on their personal statements and letters of recommendation. What we are looking for is strong evidence that the students can do research (not just coursework), and the best evidence is that the student has already done substantial research.  Many of our grad students come to us with multiple publications already—more than I had when I got my first faculty position.  Narrative transcripts would not be a good substitute for letters of recommendation from faculty that had supervised research—the signal we’re looking for would be buried in the noise of irrelevant comments for coursework that is not that important to us.

As a homeschooling parent of a high school junior who is likely to fit in best at a super-selective college like Harvey Mudd, MIT, or Stanford, I worry a lot about how to put together his transcript, school profile, and counselor letter to show that he really would fit in. There are mailing lists with 1000s of readers dedicated to parents worrying about how to get their home-schooled children into appropriate colleges (hs2coll@yahoogroups.com, for example).  I’m having to rely heavily on external validation of his coursework, much of which is not even accredited.  SAT 2 and AP exams form part of that validation, while college and university courses form another part.  Science fairs and contest exams (AMC12 and AIME in math, F=mA in physics) form yet another part, though his contest scores are not stellar enough to make him a shoo-in at the colleges where he would fit, since he does all his exams without prep. We are trying to get letters of recommendation from the university faculty (he’s been at the top of the classes), since those will be particularly informative for admissions officers.

I’ve written blog posts about how homeschoolers can get into the University of California, which is highly bureaucratic, but fairly straightforward:

http://gasstationwithoutpumps.wordpress.com/2011/10/07/satisfying-ucs-a-g-requirements-with-home-school/

http://gasstationwithoutpumps.wordpress.com/2012/06/14/ways-in-to-university-of-california/

In short, I like narrative feedback to students and their parents, but do not find narrative transcripts to be a particularly useful way to select students from a large pool (whether for honors or for admissions to the next level of education).  Small numbers of well-selected letters of recommendation are much more helpful.

I didn’t say this on the AP forum, but I will have to provide a narrative transcript of my son’s high-school curriculum, as it is pieced together from a variety of different sources. We’ll probably provide 2 formats for the transcript: a one-page one that lists courses and grades (for those courses that have grades) and a multi-page transcript that describes the content and level of each course in more detail.  Admissions officers in a hurry can glance at the one-page summary to see that he has taken all the expected courses, and those with more time or more interest can read the detailed descriptions to see that the courses were solid, even if not officially accredited.

Teachers participating in this discussion seemed to be in agreement that an AP class had several purposes, and that the most important ones were teaching the kids how to master college-level material and instilling both a knowledge of and a love of the subject.  Preparing for the exam was seen as a secondary goal at best—useful for calibrating the level of the course and with the possible college credit as a nice incentive to get students to study, but not the central focus of the teaching.  I found the discussion refreshing—teachers were talking about the goals of their courses and the value of different assessment techniques without falling into defensive postures or reciting meaningless eduspeak mantras.  There was a general feeling that the AP test was about as good as a 3-hour test could be and useful for calibrating course levels, but that a single data point was not sufficient for evaluating student performance.

I did not see teachers blaming students or prior teachers for poor performance, nor talking about doing a lot of “test prep”, which seem to be the big problems with how standardized tests are handled in schools in discussions I’ve seen elsewhere.  The attitude among the AP teachers seems to be that if they teach a good course with student engagement in a lot of the right content, then the test will take care of itself.  Most of the discussion on the AP list is about lesson plans, text books, sources for lab supplies, debugging lab procedures or test questions, and (at this time of the year) review materials.  There are occasional complaints about administrators (mostly about ridiculously little teaching time for the course or overcrowded labs, but sometimes about administrators tying teacher evaluations to the single 3-hour test taken by the students), but most of the discussion focuses on the content and pedagogy.  I wish there were such discussion sites for the college-level courses that I teach.

## 2013 April 23

### Chapter 22 homework

We finally finished off Chapter 21 of Matter and Interactions today, about 2 months behind my original schedule, having been repeatedly distracted.  We never did get around to measuring the magnetic field of a coil as a function of distance or current, either, though we’ll probably get back to trying that after the AP exams.

It looks like there is a chance my son will get to take the AP CS and AP Physics C: E&M exams this year, even though my first 5 attempts to find a place for him to take them failed. He needs to take the late exam for AP CS, since it conflicts with the Oregon Shakespeare Festival field trip and no one in the County offers Physics C—my attempts to get one of the high schools to offer the exam (which is at the same time as Physics B) all failed.  His consultant teacher is trying to arrange to be the proctor for him on the late AP CS and the late Physics C: E&M exams (it is now too late to register for the regular exams) through another high school in the same district.  I’m hopeful that she’ll be more successful in moving the bureaucracy than I was as an outsider.

Of course, he’ll probably never get any credit for taking the exams, since many of the schools he is applying to don’t do AP credit anyway, and he’ll have to retake physics at any of the schools he’s likely to choose.  But the exams will help validate that he has done rigorous work in physics, which should help him get into the colleges that would be a good fit for him. The AP CS exam is so low level that all it validates is that one has learned some Java syntax—but it might help with admissions offices also, as most will not be familiar with the new Art of Problem-Solving Java course.

In any case, we have to speed up a bit on the physics, despite the distractions, so here are the problems for Chapter 22 “Patterns of Fields in Space”: 22P15, 22p16, 22p18, 22P22, 22P23, 22P25, 22P29, 22P31, 22P33, 22P37.

## 2013 April 20

### College tours around LA

Sorry I’ve not been posting this week, but I’ve been on the road with my 11th-grade son around Los Angeles for science fair and college campus tours.

On Monday and Tuesday, we had the California State Science Fair, where he had a project in the math and software high school division, and I was judging in the math and software middle-school division.  He did not expect to win anything this year, as he had a fairly straightforward engineering project—the Arduino data logger that he wrote for my circuits class to use.  The project was well done for a high school student (comparable to some senior projects I’ve seen by college students), but not flashy in the way that science fair judges like. Indeed he did not win anything at state this year, but he was one of only 11 students who had been to state science fair 6 or more times—so he shows consistent quality and perseverance, even if he never wins the lottery that science fair judging often is.  The top math and software award at the high-school level this year went to a math project (not a software project), which is a bit unusual.  I did not read the poster for it in any detail, which I now regret, as it must have been pretty good to overcome the usual judging bias in favor of software.

The middle-school math and software category had a unanimous vote for the first-place project: an ambitious image-processing project with an interesting application and pretty good code (properly commented—a rarity at the middle-school level or even the high-school level).   The order of the next few projects was more strongly debated, but all of them were very good projects, and the order ended up depending more on the tastes and persuasive abilities of the judges than on the inherent merits of the projects.

Since we were down in Los Angeles for the science fair, we decided to extend the trip by 3 days to visit three colleges in the area: Caltech, UCLA, and Harvey Mudd.  [The science fair is right by USC, but that was not our list of colleges to visit—we've seen the campus often enough, and the academic program did not appeal.] Originally we had planned a west-to-east sweep (UCLA, Caltech, Harvey Mudd) to minimize the transit time, but Caltech was not doing tours on Thursday and Friday (preparing for their admitted-students yield event this weekend), so we changed the order to Caltech, UCLA, Harvey Mudd. To get from the science fair to Pasadena, we took a DASH bus, the red line (subway), and the gold line (light rail).  That used 2 different transit systems (LA DOT runs the DASH buses, and Metro runs the subway, the light rail, and all the other buses that we took on this trip).

I couldn’t find any reasonably priced motels or hotels near UCLA in my on-line searches, so we stayed one night in Pasadena and two nights in Claremont, with the UCLA tour sandwiched in between the 2-hour, 2-bus Pasadena-Westwood and 3-hour (bus, subway, train) Westwood-Claremont transits.  I had originally planned to take a taxi from UCLA to Claremont (a pretty expensive ride across Los Angeles), but my son wanted to include a Metrolink commuter rail link in the trip somewhere in our trip, so we ended up taking the Metro number 2 bus from UCLA to the red line, the red line to Union Station, and Metrolink to Claremont.  The subway and commuter rail portions were fairly pleasant, but the number 2 bus was so full that we felt guilty for having luggage—Metro probably needs to run more buses on that route during rush hour.

The LA transit system is usually maligned by the locals, who claim that it is so bad that they have to drive everywhere, but it seemed pretty reasonable to us—under-utilized, perhaps, but reasonably quick and with decent connections.  Of course, just about any local bus system will only provide about 10-mile-per-hour transportation, so bicycling is almost always faster, but that is an option that is seems very , very few people choose in Los Angeles.

OK, enough on transit, what about the 3 colleges?

At Caltech we had a very small tour group (just 3 prospective students) and a friendly, barefoot tour guide.  We were shown the Caltech “houses” and the guide talked a lot about Caltech traditions.  Some of the traditions (like the honor code) seem great, but a lot of the other traditions seemed to be based mainly on rivalry, competition, and mean-spirited pranks. The social activities mentioned (like the interhouse parties) seemed to be mainly competitive events also (which house could build the most elaborate set for their party).  We saw almost no students while on the tour, no classrooms, no professors—very little other than the houses and the outsides of buildings.  The campus seemed strangely deserted for a Wednesday afternoon in the middle of the term.

The Caltech campus does have some nice-looking buildings, and there are supposedly a lot of Nobel prize winners around, but we didn’t hear much about students actually interacting with the professors—the impression was that the professors mainly kept their heads down and did research with their postdocs and grad students. My son had tried to arrange meetings with a computer science faculty member by e-mail, but the first one he contacted suggested he talk to someone else, and that person said he was too busy, but that my son should just wander down the hall and stick his head in an open door.  We ended up not talking to any Caltech faculty or even seeing any from a distance.

The one academic message that we got from Caltech was “physics”.  They teach physics at Caltech—occasionally they give it a different name (math, chemistry, computer science, engineering, … ), but when you look at the research interests of the faculty, it is almost all physics in different flavors.  My son likes physics, and would probably do ok at Caltech, but he has other interests as well, and Caltech does not seem to provide instruction or opportunities in them.  He also likes doing applied work more than theory, and Caltech (according to the student tour guide and what we could glean from the web) is very theory-oriented.  Caltech does have some theater that he could participate in, but their entire “theater and visual arts” program apparently fits in a small 2-story house and a shed at the corner of campus, and there was no one around on a Wednesday afternoon to get any information from.

UCLA was in many ways the opposite of Caltech.  It is a large, bustling campus, crowded with students the whole time we were there. Students walked or hung out in groups (very little wheeled transportation, because of the number of hills and stairs).  There did not seem to be many quiet places on campus (unlike Caltech, where the entire campus seemed to be silent).

The tour group we were with for a 2-hour walking tour was large—probably 15 students plus accompanying family members.  The tour guide showed us many buildings (including the insides of a nice library), but no residences (which are a 20-minute walk away from the academic buildings), and she told us about admissions and other generic information.  The campus tours seem to be entirely student run (the campus tours office is in the student government building and staffed entirely by students), rather than part of the admissions office.  The tour was pretty good, for a large, generic tour, and UCLA does have some nice-looking buildings (and nice-looking students, but I’m not supposed to notice that).

We had arranged a meeting with a CS faculty member, who told us about his classes and research. Undergrad computer science at UCLA has huge classes (60–80 in upper-division courses, and three times that in lower-division courses). The faculty member told us that he does not allow undergrads into his grad courses and that few undergrads get research opportunities.  He did not have numbers, but estimating from what he said, it sounds like only about 5% of CS majors at UCLA get involved in faculty research—an appallingly small number.  It sounds like it is hard for an undergrad at UCLA to get a first-rate computer science education, because they are so focused on pumping through huge numbers of OK students.

UCLA does have a great reputation in theater, so we went over to the opposite side of campus to find out whether a non-theater major could ever get roles.  We did not talk to a theater faculty member nor an administrator, but to a friendly group of theater majors.  They basically said that non-majors had essentially no chance of getting a role (or even tech work) in any theater department production—even the theater minors only got theater-appreciation classes, not acting classes.  They did say that there were some non-departmental theater productions, but that they knew almost nothing about them.  In short, it sounded like what my son wants (a really advanced computer science education with the ability to do a fair amount of acting on the side) is not available at UCLA.

I had expected Harvey Mudd to be similar to Caltech.  They both have reputations for being very techie schools with impossibly high workloads, and Harvey Mudd was started by someone with close ties to Caltech.  They both have a similar-sounding common core requirement and both have a very pure form of honor code (tests are unproctored take-home exams, with students responsible for timing themselves as well as following directions about whether notes and books are permitted).  There were a number of observable differences, though, even on a one-day visit:

• Harvey Mudd has some of the ugliest buildings I’ve seen on any college campus.  The concrete block buildings with “warts” make UCSC’s cast concrete bunkers look stylish in contrast.  It is clear that Mudd has not been investing in the amenities wars—there is no luxury here.  The interior of the dorms look a lot like the concrete-block dorms I lived in back in the early 70s at Michigan State, but perhaps even more crowded.
• The campus is small.  Our walking tour showed us every building on campus, including a walk through the main academic building, showing us classrooms, faculty offices, and even the wood shop and machine shop (which Mudders can use 24/7 once they have passed the safety training). The class in which students have to make a hammer to specifications from a chunk of wood and a chunk of metal seems like a good, practical course.
• The campus is flat, so wheeled transportation is common (bikes, unicycles, skateboards, long boards, and freeline skates seemed the most popular).
• The density of students was between that of Caltech and UCLA.  There were plenty of students around, but it was never so crowded or so loud as to be claustrophobic. A lot of the students were wearing geek T-shirts and seemed likely to be the sorts of kids my son would get along well with.
• Faculty were clearly visible—one physics professor even kibbitzed the tour guide as he was giving the explanation of the physics core courses.
• The admissions office gave my son a ticket for a free meal at the dining hall (and a reduced-price ticket for me).  We had lunch there, and the food was pretty good for a dining hall—more important it included several things that my son would eat on a regular basis.  We also noticed that several of the faculty ate there.  I don’t know if Harvey Mudd encourages the faculty to eat with the students (free lunch might do the trick, or the unavailability of other options), but it was good to see faculty and students in the same hall, even if at different tables.  I also noticed that none of the students were eating alone—almost everyone was in a group of 2 to 10 students. For a group of geeks, that is a rather astonishing bit of social engineering—I wonder how they accomplished it.
• My son was also given a list of all the classes meeting at Harvey Mudd this semester and invited to sit in on any of them.  Unfortunately, we were there on a Friday, so few classes were meeting (mostly long labs).  We sat in on one of the “choice” labs for a while, and saw mainly one-on-one mentoring by the faculty member, which was good to know about, but not very exciting to watch.
• Harvey Mudd does have an 11-course humanities, social science, and arts (HSA) requirement, about half of which has to be done at Harvey Mudd, with the rest usually being done at the other Claremont colleges.  It would be possible for him to do a theater concentration (5 theater-related courses), by taking the one Harvey Mudd theater course (simply titled “Shakespeare”) and 4 courses at Pomona.  Most of the Mudders take a fair number of courses at the other Claremont colleges—usually PE courses and courses in their HSA concentration, and cross-registration seems to be fairly straight-forward, since the Claremont colleges share a common registration system.
• There is an aikido course at Scripps that my son could take for PE—he’s not done aikido since he was quite young, but thinks that he would enjoy picking it up again more than most PE options.
• My son had made an appointment with a computer science faculty member and we had a good conversation with him about the Harvey Mudd requirements and opportunities in computer science.  All the computer science students have to do research or development projects and most do more than one (the senior clinic plus one or more summer research projects).  There seems to be enough depth in courses and research in the fields my son is interested in that the lack of grad courses is not really important.  Even the required common-core first course in computer science has an option for students sufficiently advanced in CS, so that he would not have to repeat stuff he’s already done.
• The tour guide talked a lot about coöperation, mentoring, and group projects—concepts that were independently brought up by the admissions officer and by the CS faculty member.  The group projects don’t seem to be the one-person project forced on a group that most middle-school and high-school projects are, but projects big enough to benefit from multiple people working on them.  They do practice pair programming in most CS classes, which will be a new experience for my son.

Although I had expected Caltech and Harvey Mudd to be very similar schools from what I knew before the visits, I ended up with very different impressions of them.  Caltech seems to be a competitive school with a physics-centric, theoretical focus, while Harvey Mudd is a cooperative school with an applied engineering focus.  My son will probably apply to both, since getting in is largely a lottery (they both have about a 10% acceptance rate and his test scores are only average for either school), but I think that he’d end up much happier at Harvey Mudd.  UCLA looks much less attractive (other than financially), but he’ll probably apply to several of the UC schools as he is much more likely to get into them.

## 2013 April 7

### Destroying a hard drive

Filed under: home school,magnetometer — gasstationwithoutpumps @ 13:08
Tags: , ,

Sorry that I’ve not posted in a week, but my laptop has been in the shop, getting the hard drive replaced.  The destruction of the old drive happened last Sunday in a physics lab I was doing with my son.  We were planning to measure the magnetic field of a coil as a function of current, distance, radius, or number of turns (but probably not all those variables, as that would have gotten tedious).  We weren’t getting a noticeable reading from the magnetometer, so I got out a neodynium magnet to see if the magnetometer was working.  It was—in fact the magnet saturated the magnetometer easily.  When I went to turn off the program that was streaming data from the magnetometer, I carelessly put the magnet down on my laptop—right over the hard drive. That mistake turned out to be an expensive one.

The computer continued to work that day, but the next time I tried to restart it, it wouldn’t boot up.  I took it down to the local computer shop on Monday, where I found out that the extended warranty had expired 6 months ago, so I had to pay labor as well as materials for replacing the disk, which ended up costing me $376 (as long as they were replacing the drive, I had them upgrade from a 500GB drive to a 1TB drive, since I was running out of disk space). When I finally got the computer back on Saturday, I spent most of the day restoring the system from my backup drive. Now I need to replace the backup drive, since Time Machine complains that the old drive does not have enough space to do a full backup. It looks like that will cost me another$100–$150 for a 1–2TB backup drive. I don’t have many choices of drive, since I need a Firewire 800 interface (my old MacBook Pro does not have USB 3 or Thunderbolt). So my moment’s carelessness cost me the use of my laptop for a week and about$500.

After having confirmed that the magnetometer was ok, we did a rough calculation of how strong the field from the coil should be, to see whether we ought to be detecting. (I know, we should have done that first.)  We were running about 33mA through a coil of 5 turns with a diameter of about 4.4cm. Using the formula $B(z) = \frac{\mu_0}{4\pi} \frac{2 \pi R^2 N I}{(z^2+R^2)^{3/2}}$, with I=0.033A, R=0.022m, and N=5, I computed that the magnetic field right at the center of the coil (z=0m) should be 4.7µT,  at 1cm (about as close as I could get the magnetometer) it should be 3.6µT, and at 2cm (where the measurements were being attempted) the field should be about 1.9µT.  The magnetometer has a resolution of 0.1µT per count, but the noise level was high enough that counts of 20 (2µT) would have been barely detectable. I suspect that a lot of the noise was because we had not immobilized the magnetometer.  According to the World Magnetic model, as displayed in Wikipedia, we should have about 49µT at a 60° inclination due to Earth’s field, so changes in orientation of 1° in the magnetometer would causes changes of about 0.9µT.

We’ll repeat the experiment (without having a strong magnet near the laptop!) using more current (say 300mA), more turns (40), and a smaller radius (a diameter of 1.25cm). With those values, we should be able to get a field of  1.2mT at the center of the coil, 180µT at 1cm, 32µT at 2cm, and 11µT at 3cm. We’ll also immobilize the magnetometer in my plastic-jawed Panavise, and make measurements by subtracting the field with the current off from the field with the current on. We may even double the signal by subtracting the field with the current in one direction from the field with the current in the opposite direction.

Next Page »