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2016 November 13

BioTreks—a specialized research journal for high-school students

Filed under: Uncategorized — gasstationwithoutpumps @ 18:09
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Five and half years ago, I published a blog post, Journals for high school researchers, which listed the tiny number of venues I knew of that were open to high-school researchers.

At iGem this year, I heard about a new peer-reviewed journal for high-school students: BioTreks.  Currently the journal is planning on one issue a year, and solely on the subject of synthetic biology, which seems a bit narrow to me:

In 2016, BioTreks will begin publishing open access, peer-reviewed articles related to the implementation and outcome of high school student-driven synthetic biology research. We’re currently accepting original articles that present perspectives, methodologies, and outcomes related to the study and practice of synthetic biology in high schools. Students, educators, and biologists from around the world are invited to contribute content that promotes and describes synthetic biology education and research at the high school level. Authors who are interested in contributing original research articles, methods papers, literature reviews, editorial perspectives to the journal are encouraged to contact us for more information. We look forward to hearing more about your experiences in synthetic biology and discussing ways in which you can share your insights in our journal. Please contact us to learn more about publishing in the journal.

I chatted with one of the originators of the idea for a while at the iGEM Jamboree, and they may be open to expanding the journal to be “synthetic biology and bioengineering”, which is a considerably wider scope, and which may open up opportunities for a lot more high school students.

I don’t know whether this would require them to rewrite their description of their goals:

Ars Biotechnica is a 501(c)3 public charity whose mission is to support science education by introducing high school students to the emerging field of synthetic biology. We do so by awarding grants for schools to use in obtaining laboratory supplies, coordinating local and regional symposia on synthetic biology, and administering a peer-reviewed journal. Our organization has been providing financial and technical support to iGEM-bound synthetic biology teams since 2013 and supporting high school focused synthetic biology symposia since late last year. We’re now excited to announce the launch of BioTreks, a peer-reviewed journal just for high school synthetic biology.

The organization has a very small budget and relies mainly on volunteers:

BioTreks is maintained by a volunteer staff of dedicated biologists, students, and educators. If you have a background in biology, education, peer-reviewed publication, or graphics design and would like to help us develop and maintain the journal, then we would like to hear from you. Volunteers can work remotely and on their own time to coach students on writing scientific papers, serve as section editors, copy editors, and peer-reviewers, and contribute to the journal’s overall presentation and design. Please contact us to learn more about volunteer opportunities at the journal.

They don’t charge anything to students for publication—they aren’t a vanity press that makes money off of selling overpriced printing to suckers students.

If anyone knows of other journals interested in high-school submissions (not vanity presses), let me know, and I’ll blog about them!

2016 September 15

Research Report | Siemens Competition

Filed under: Uncategorized — gasstationwithoutpumps @ 12:23
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I was reading the guidelines for a research report for the Siemens competition for high-school science projects.  Overall, the guidelines are good, but I have one quibble with their description of the first section:

Introduction: the “why” section (2-3 pages)

  • Start with a broad picture of the problem you have chosen to study and why it is interesting. Provide a brief review of pertinent scientific literature, describe what information is missing and how your work addresses this gap in the literature. Previous relevant publications and patents must be properly cited in the text of the Research Report and included in the Reference section of your report.
  • Describe the specific problem to be solved, the research question to be answered, the hypothesis(es) to be tested, or the product to be developed (if any). Provide a brief rationale for the research and why the work is important.

I believe that they are encouraging a common mistake: burying the lede. Theses, grant proposals, student projects, and papers should start with a direct statement of the research question or design goal of the project, then provide the “broad picture” and “why it is interesting”. I’m very tired of wading through a page or more of mush trying to find out what a student project (or published research paper) is.

Swapping the two points that they put in the first section would improve the quality immensely.

2014 October 25

Grading based on a fixed “percent correct” scale is nonsense

Filed under: Uncategorized — gasstationwithoutpumps @ 10:12
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On the hs2coll@yahoogroups.com mailing list for parents home-schooling high schoolers to prepare for college, parents occasionally discuss grading standards.  One parent commented that grading scales can vary a lot, with the example of an edX course in which 80% or higher was an A, while they were used to scales like those reported by Wikipedia, which gives

The most common grading scales for normal courses and honors/Advanced Placement courses are as follows:

“Normal” courses Honors/AP courses
Grade Percentage GPA Percentage GPA
A 90–100 3.67–4.00 93–100 4.5–5.0
B 80–89 2.67–3.33 85-92 3.5–4.49
C 70–79 1.67–2.33 77-84 2.5–3.49
D 60–69 1.0–1.33 70-76 2.0–2.49
E / F 0–59 0.0–0.99 0–69 0.0–1.99
​Because exams, quizzes, and homework assignments can vary in difficulty, there is no reason to suppose that 85% on one assessment has any meaningful relationship to 85% on another assessment.  At one extreme we have driving exams, which are often set up so that 85% right is barely passing—people are expected to get close to 100%.  At the other extreme, we have math competitions: the AMC 12 math exams have a median score around 63 out of 150, and the AMC 10 exams have 58 out of 150.  Getting 85% of the total points on the AMC 12 puts you in better than the top 1% of test takers.  (AMC statistics from http://amc-reg.maa.org/reports/generalreports.aspx ) The Putnam math prize exam is even tougher—the median score is often 0 or 1 out of 120, with top scores in the range 90 to 120. (Putnam statistics from  http://www.d.umn.edu/~jgallian/putnam.pdf) The point of the math competitions is to make meaningful distinctions among the top 1–5% of test takers in a relatively short time, so questions that the majority of test takers can answer are just time wasters.
I’ve never seen the point of having a fixed percentage correct ​used institution-wide for setting grades—the only point of such a standard is to tell teachers how hard to make their test questions.  Saying that 90% or 95% should represent an A merely says that tests questions must be easy enough that top students don’t have to work hard, and that distinctions among top students must be buried in the test-measurement noise.  Putting the pass level at 70% means that most of the test questions are being used to distinguish between different levels of failure, rather than different levels of success. My own quizzes and exams are intended to have a mean around 50% of possible points, with a wide spread to maximize the amount of information I get about student performance at all levels of performance, but I tend to err on the side of making the exams a little too tough (35% mean) rather than much too easy (85% mean), so I generally learn more about the top half of the class than the bottom half.
I’m ok with knowing more about the top half than the bottom half, but my exams also have a different problem: too often the distribution of results is bimodal, with a high correlation between the points earned on different questions. The questions are all measuring the same thing, which is good for measuring overall achievement, but which is not very useful for diagnosing what things individual students have learned or not learned.  This result is not very surprising, since I’m not interested in whether students know specific factoids, but in whether they can pull together the knowledge that they have to solve new problems.  Those who have developed that skill often can show it on many rather different problems, and those who haven’t struggle on any new problem.

Lior Pachter, in his blog post Time to end letter grades, points out that different faculty members have very different understandings of what letter grades mean, resulting in noticeably different distributions of grades for their classes. He looked at very large classes, where one would not expect enormous differences in the abilities of students from one class to another, so large differences in grading distributions are more likely due to differences in the meaning of the grades than in differences between the cohorts of students. He suggests that there be some sort of normalization applied, so that raw scores are translated in a professor- and course-specific way to a common scale that has a uniform meaning.  (That may be possible for large classes that are repeatedly taught, but is unlikely to work well in small courses, where year-to-year differences in student cohorts can be huge—I get large year-to-year variance in my intro grad class of about 20 students, with the top of the class some years being only at the performance level of  the median in other years.)  His approach at least recognizes that the raw scores themselves are meaningless out of context, unlike people who insist on “90% or better is an A”.

 People who design large exams professionally generally have training in psychometrics (or should, anyway).  Currently, the most popular approach to designing exams that need to be taken by many people is item-response theory (IRT), in which each question gets a number of parameters expressing how difficult the question is and (for the most common 3-parameter model) how good it is at distinguishing high-scoring from low-scoring people and how much to correct for guessing.  Fitting the 3-parameter model for each question on a test requires a lot of data (certainly more than could be gathered in any of my classes), but provides a lot of information about the usefulness of a question for different purposes.  Exams for go/no-go decisions, like driving exams, should have questions that are concentrated in difficulty near the decision threshold, and that distinguish well between those above and below the threshold.  Exams for ranking large numbers of people with no single threshold (like SAT exams for college admissions in many different colleges) should have questions whose difficulty is spread out over the range of thresholds.  IRT can be used for tuning a test (discarding questions that are too difficult, too easy, or that don’t distinguish well between high-performing and low-performing students), as well as for normalizing results to be on a uniform scale despite differences in question difficulty.  With enough data, IRT can be used to get uniform scale results from tests in which individuals don’t all get presented the same questions (as long as there is enough overlap in questions that the difficulty of the questions can be calibrated fairly), which permits adaptive testing that takes less testing time to get to the same level of precision.  Unfortunately, the model fitting for IRT is somewhat sensitive to outliers in the data, so very large sample sizes are needed for meaningful fitting, which means that IRT is not a particularly useful tool for classroom tests, though it is invaluable for large exams like the SAT and GRE.
The bottom line for me is that the conventional grading scales used in many schools (with 85% as a B, for example) are uninterpretable nonsense, that do nothing to convey useful information to teachers, students, parents, or any one else.  Without a solid understanding of the difficulty of a given assessment, the scores on it mean almost nothing.

2014 April 11

Arthur Benjamin: Teach statistics before calculus!

I rarely have the patience to sit through a video of a TED talk—like advertisements, I rarely find them worth the time they consume. I can read a transcript of the talk in 1/4 the time, and not be distracted by the facial tics and awkward gestures of the speaker. I was pointed to one TED talk (with about 1.3 million views since Feb 2009) recently that has a message I agree with: Arthur Benjamin: Teach statistics before calculus!

The message is a simple one, though it takes him 3 minutes to make:calculus is the wrong summit for k–12 math to be aiming at.

Calculus is a great subject for scientists, engineers, and economists—one of the most fundamental branches of mathematics—but most people never use it. It would be far more valuable to have universal literacy in probability and statistics, and leave calculus to the 20% of the population who might actually use it someday.  I agree with Arthur Benjamin completely—and this is spoken as someone who was a math major and who learned calculus about 30 years before learning statistics.

Of course, to do probability and statistics well at an advanced level, one does need integral calculus, even measure theory, but the basics of probability and statistics can be taught with counting and summing in discrete spaces, and that is the level at which statistics should be taught in high schools.  (Arthur Benjamin alludes to this continuous vs. discrete math distinction in his talk, but he misleadingly implies that probability and statistics is a branch of discrete math, rather than that it can be learned in either discrete or continuous contexts.)

If I could overhaul math education at the high school level, I would make it go something like

  1. algebra
  2. logic, proofs, and combinatorics (as in applied discrete math)
  3. statistics
  4. geometry, trigonometry, and complex numbers
  5. calculus

The STEM students would get all 5 subjects, at least by the freshman year of college, and the non-STEM students would top with statistics or trigonometry, depending on their level of interest in math.  I could even see an argument for putting statistics before logic and proof, though I think it is easier to reason about uncertainty after you have a firm foundation in reasoning without uncertainty.

I made a comment along these lines in response to the blog post by Jason Dyer that pointed me to the TED talk. In response, Robert Hansen suggested a different, more conventional order:

  1. algebra
  2. combinatorics and statistics
  3. logic, proofs and geometry
  4. advanced algebra, trigonometry
  5. calculus

It is common to put combinatorics and statistics together, but that results in confusion on students’ part, because too many of the probability examples are then uniform distribution counting problems. It is useful to have some combinatorics before statistics (so that counting problems are possible examples), but mixing the two makes it less likely that non-uniform probability (which is what the real world mainly has) will be properly developed. We don’t need more people thinking that if there are only two possibilities that they must be equally likely!

I’ve also always felt that putting proofs together with geometry does damage to both. Analytic geometry is much more useful nowadays than Euclidean-style proofs, so I’d rather put geometry with trigonometry and complex numbers, and leave proof techniques and logic to an algebraic domain.

2014 January 28

High school senior workload

Filed under: home school — gasstationwithoutpumps @ 22:00
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Shireen Dadmehr, in Math Teacher Mambo: Seniors, Workload, Responsibility, talks about high-school seniors dropping out of her CS course:

The flip side of this is that depending on what courses the students take their senior year, and how they approach their scholarship applications and college applications, and what sports they play, and how far their daily commute is, the amount of time they have for homework and sleep and life fluctuates. Needless to say, there are stressed out little bundles of walking sleepless zombies.

Her dilemma is whether to push the students to stick with what they signed up for or to let them drop courses that are either too ambitious for them or just lower priority in an over-loaded schedule. My advice to her is simple—talk to the students and make sure that they aren’t just scared of the material or not getting it due to things that could be changed in the teaching, but let them make their own decisions about whether the effort is bringing enough reward.

As a home-schooling parent of a high-school senior, I’ve also got to deal with helping my son balance his workload—I have high standards and high expectations for him, and I’d like to have him do everything he started this year, but some things are taking more time than anticipated, so it is time to re-evaluate the importance of different activities.

The second semester is starting now, so this is the ideal time to rebalance the workload.

His first semester was supposed to be econ, AP chem, writing (a mix of college essays and tech writing),  group theory, two computer science/computer engineering projects (the light gloves and upgrades to the Arduino data logger), and theater.  The mix of what was done was not quite what was envisioned—more of some things and less of others.

The AP chem and econ are pretty much where they should be (a few days behind in chem due to illness, about a week to go to finish econ) at the semester break.

The college essays turned out to take far more time and effort than originally anticipated (by me and him—his mother had a more realistic view), which pushed the tech writing out.  The college essays got done, but only at the expense of no winter break. Luckily this problem was seen early enough that the transcript was revised to describe his fall semester English class more accurately.

More acting got done than originally expected (and we originally expected a heavy acting load), as he ended up with 5 roles (rather than 1 or 2) in the school one-acts and he added a 3-day workshop during winter break.  This last month has been crazy, with performances almost every weekend, but things should wind down after the Dinosaur Prom Improv performance this Sunday, to just 2 theater classes a week (Dinosaur Prom and Much Ado About Nothing).  The two going away are the Page-to-Stage theater class (where he was the oldest student) to make room for younger kids on the waiting list for the spring production, and the school production which is once a year and had the performance last weekend.  With 2 theater groups instead of 4, he should have more time for other classes.

He’s been working diligently (often spending more time than he really has available) on the light gloves.  In addition to hours of programming or hardware design he’s been meeting weekly or more with the team and having Skype/Google Hangout meetings with investors and with new, remote engineers thinking of joining the team.  I think that they’re getting their second set of prototypes fabricated this month, and he’ll need to start intensive programming to get the Bluetooth LE chip working and communicating with a laptop or cell phone.  I believe that they are getting 10 prototype boards assembled commercially, rather than having to deal with the surface mount parts themselves—the price was low enough that the time savings (and probable quality) justified the extra price.  I think that they are still planning to have a Kickstarter campaign this spring and go into production over the summer, but that schedule may slip if the programming and debugging takes longer than they expect.  (Note: I’m not involved in this project, except once in a while as someone to bounce ideas off of, so all those “I think” and “I believe” statements are vague impressions not the result of detailed status reports.)

The Arduino Data Logger project was put on hold over the fall, but I really need him to get back to that very soon, as I’ll have to tell the staff whether to order Arduino boards or KL25Z (or KL26Z) boards for my circuits class soon.  The extra features that I requested are not critical, but we can’t use the KL25Z boards unless they are supported by the data logger software, and it would be nice to have the much higher resolution and sampling rate of the KL25Z boards.

Because group theory was always last on the priority list and had only Dad-imposed deadlines, it has lost out.  We’re still in Chapter 3, and I don’t see much hope of our catching up by the end of the year.  I see three choices:

  • Drop Group Theory from the transcript, treating as a nice idea that there just wasn’t time for.
  • Push real hard to try to complete the book anyway—I don’t see this happening, as the group theory is just fun math, not something he “needs”, so it I want it to be something we do together for fun, not under high stress.  It is the lowest priority of our courses in my mind, so I can’t see pushing him hard on it.
  • Reduce our ambition to only ½ or even ⅓ of the book, and reduce the credits for the course correspondingly.

He’s finished with econ (almost) and with college essays, but is picking up government/civics and dramatic literature.

The civics will probably be at about the same effort level as the econ, but it may be hard to find a good source at the right level—the MIT open courseware econ lectures made a nice, rather lightweight econ course, supplemented by a few popular-press econ books.  Government/civics doesn’t have the mathematical appeal of econ, and most high-school or freshman college books on the subject are rather dry and boring.  Oh, well, that course is my wife’s responsibility (as was the econ), and she can undoubtedly do a better job of finding materials for it that I could.

The dramatic literature course is preparation for the trip to the Oregon Shakespeare Festival and should not be a problem for him—certainly nothing like the torture of college-application essays!  He’s done two previous dramatic literature courses with the same teacher (different plays each year, based of the OSF schedule), and knows what to expect.

So this spring semester should see

  • replacement of econ by civics
  • replacement of college-application essays by dramatic literature
  • continuation of AP Chem
  • switch from mostly hardware and app/web programming to embedded software for light gloves
  • two-fold reduction in acting (down to a sane level)
  • addition of data logger project
  • low-level continuation or elimination of  group theory

I think that the spring is likely to be less stressful than the fall, but still a full load.

We’ll have to make a decision on the group theory soon, for the updated report through the Common App.

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