Tag Archives: blogs

Grading statistics – blog period 1

Grading has finished for blogging period 1.  In this post I’ll give some information about the grade distribution, and comments.

Blogs1Here is a bar chart showing the overall grade distribution for blogging period 1.  Let me break down some of the numbers here.

  • There are 20 students in the D and F area. Almost without exception, these are students who either have posted nothing at all, or posted their initial introduction (required in Week 1) and then stopped.  Because of the best-of-three-periods algorithm that I am using for the blogs, these students still have two opportunities to succeed in this component of the course; I hope they take advantage of it.
  • Among those who did post something substantive, many did not post enough to obtain higher than a “C” grade.  For a “B”, the syllabus requirement is one post a week.  This does not seem too demanding, especially for a class without other homework assignments.
  • Many posts contained simple errors that could be eliminated by re-reading them more carefully: links that do not work, math calculations that do not yield the answer stated, mistakes about units (confusing dollars with cents was surprisingly common – let’s hope students don’t do that in real life!)
  • A quality post does not just contain numbers, but uses quantitative reasoning to advance an argument.  A good way to do this is to make comparisons between different scenarios.  Sarah’s sample post is a good example of this.
  • It was interesting to see so many posts that tried to evaluate some “sustainability”-related change (should I use bottled water?/buy a hybrid car?) in financial terms alone.  Sometimes the “sustainable” approach will save money, sometimes it may not.  I would have liked to see more discussion of the trade-offs that are inevitable in such decisions – I sometimes got the impression that the financial bottom line was going to settle everything.
  • Even in the best posts there was room for improvement in presentation, argument and referencing.  I will be glad to talk in office hours with anyone who wants help working on their blogging skills or crafting a quality post.


Blogging Theme Week 5

This is the final week for your blog postings to be graded in the first blogging period.  Remember, there are three such periods, and the blogging component of your overall grade will be based on your best performance over all three such periods.

A brief reminder about blogging requirements: you may post on anything related to the course (the “theme” for the week is only a suggestion), and your postings will be graded according to the rubric that appears in the syllabus,  The rubric involves five grading elements: frequency of posting, mathematical content, thematic content, organization and presentation, references and connections.  Blogging is your only “homework” for this course and a high standard will be expected.

The suggested blogging theme for this week is Bad Math.  This is in conjunction with the presentation that I will give on Wednesday.  The idea is to identify a web page or newspaper article or media soundbite which uses numbers or mathematical jargon in a misleading way. Here’s a link to a post that suggests some ways to identify “misleading numbers”.  Remember, you are also welcome to post on any of the earlier themes (or on any other topic).

Events Schedule, Week 5

Here is the schedule for the fifth week of class.

  • Monday 2/9,  2:30 – 3:20, Class Unit  2.1 (115 Osmond)
  • Monday 2/9, 4:00-5:00, Kaley Weinstein’s office hour and tech support (101 McAllister)
  • Tuesday 2/10 3:30-4:30, Sara Jamshidi’s office hours, 419 McAllister
  • Wednesday 2/11 2:30 – 3:20, Class – Case Study – “Bad Math” John Roe (115 Osmond)
  • Thursday 2/12, 10:30 – 12:00, John Roe’s office hours, 204 McAllister
  • Friday 2/13, 2:30 – 3:20, Class Unit 2.2 (115 Osmond)
  • Friday 2/13, midnight,end of first blog grading period

Readings for  classes are available at


Alternative office hours are available on request by contacting me.

Thoughts about blog posts

So we are more than halfway through the first blog assessment period.  The TAs and I have read through everything that you all have posted.  There are a lot of interesting ideas out there, ideas that, with a bit of thought, could be developed into excellent posts.  (And remember, you can go back and edit your post, until the end of the blogging period, if you want to improve it; the final grade will be based on the final version of your post.) But fewer of the posts are excellent right now.  Here are some suggestions for the future.

  1. You cannot get points for posting if you don’t post.  As of right now, 8 class members have not made any posts at all, and a further 16 have not posted anything beyond the introduction that was required in week 1.  Yes, I know that according to the grading rules, you can in theory make things up in the second or the third blogging period, but it will take practice – practice which might as well start now.
  2. Posts should contain numbers, but should also set those numbers in context.  Too many posts suffer from the “gee whiz” use of numbers (this is a problem with a lot of environmental writing generally, I find): “if we all did this simple thing we could save 3000 barrels of oil a year”.  All well and good, but how does 3000 barrels a year compare to the total amount of oil that “we” are responsible for consuming?  Is it huge in relation to our total consumption, or insignificant? If insignificant, is it worth the time to do the simple thing (whatever it is)? What are the costs of doing the “simple thing”? etc.
  3. Posts should also contain calculations: it’s not a math post just because you quote a lot of numbers from some web site or other. This post for instance tries to do that by expressing energy consumption of different countries in terms of the number of people who consume one MToe/year.
  4. I’d like to see a clearer awareness of the distinction between environmental benefits (accruing to society at large) and financial benefits (maybe to the individual consumer) – I’m thinking of some of the posts about hybrid cars here, for example.  Related, though not the same point, is to make some effort to quantify trade-offs: if putting solar panels on my roof costs me x dollars right now, and saves me y dollars per year using net metering, how many years will it take to pay back my investment?  (This particular example requires some financial math, about the present value of an annuity, that we will cover in the next chapter.)

Okay, that’s enough suggestions for one post!   Remember that I or the TAs are happy to talk about your blogging during office hours or at any other time by appointment…

Blogging theme, week 2

The blogging theme for this week is Water.   A brief reminder about blogging requirements: you may post on anything related to the course (the “theme” for the week is only a suggestion), and your postings will be graded according to the rubric that appears in the syllabus,  The rubric involves five grading elements: frequency of posting, mathematical content, thematic content, organization and presentation, references and connections.

Because from now on we will be looking for actual mathematics, you may want to review this post which explains how to include mathematical expressions like

[ 5.7 times 10^{11}, qquad y = mx + c, qquad frac{1 – r^{n+1}}{1-r} ]

in your posts.

Suggestions (possible starting points) related to the theme.

  • Find examples of water waste, either in the US or abroad.  You could focus on agricultural, industrial, or domestic use.  Make suggestions for reducing the level of waste, and quantify the amount of water that could be saved by implementing them.
  • Carry out an Internet search on the term “water pricing”.  Give examples of apparently irrational pricing or of conflicts over water prices.  Does it make sense to speak of a single “price of water”?
  • Think about bottled water.  How many disposable drinking-water bottles are used every year on the University Park campus?   Estimate how much oil is used to make these bottles and to ship the water here.  Compare with the energy costs of delivering water by pipe.   Why is bottled water so popular? Is the bottled water industry sustainable?
  • Learn about the concept of “virtual water”, that is, water that is embodied in other products that we consume.   Give some calculations of the amount of virtual water in various consumables.  On a “virtual water” basis, where does most of our water consumption come from?
  • The Greenland ice sheet is roughly 600,000 square miles in area, and on average is over a mile thick.   If all that ice were to melt and end up in the ocean, by how much (on average) would global sea levels rise?  Show how you do the calculation.
  • Write about groundwater supplies in the southwestern US.  (This article by Jay Famiglietti, Senior Water Scientist at the NASA Jet Propulsion Laboratory, is a good place to start.)

Blogging feedback

I’ve now reviewed all the introductory posts on the student blog.  It is fascinating to see the variety of backgrounds and experiences of the students in this course.  Thanks for sharing your ideas.  Those of you who did not make an introductory post, we missed your contribution!  (You also did not help your grade any, but I imagine you’re already aware of that.)

I noted a number of things that might help some students improve the quality of your posts.

  • Make sure your post has a title.   (“Untitled Post” does not count.)
  • Use categories and/or tags to describe post content.
  • Follow instructions.  For instance, if asked for a picture, make sure to post one!
  • Don’t forget to comment on the posts of others, as well as to post on your own account.
  • Make sure that any URLs you include are active (clickable) hyperlinks.  I’ve asked Kaley to make a tech support post about generating hyperlinks.

Please contact Kaley with any  blogging questions.  If necessary, we can easily schedule another tech support session in a computer lab this week.

About the blog grading

I MODIFIED THE “CUMULATIVE SCORE” IDEA that was in an earlier version of this post.  See below for details.

This post is to explain how to read your blogging grades on ANGEL.

As is explained on the syllabus, the blogging component is worth 35% of your grade.  There are three five-week “blogging periods” ending 2/13, 3/27 and 5/1, each of which will be assessed separately.  The best score over the three blogging periods will be counted towards your grade.

When you look on the ANGEL gradebook for your course, you will see three “assignments” for blogging, one corresponding to each of the three blogging periods.  When each blogging period is completed, the assignment will record your score for that period.  This will be scored out of 50, and then scaled to represent 35% of the total grade points available.

The instructors will meet each Monday to review the blog postings for the previous week. However, the grade is awarded for the blogging period as a whole.  After some thought, I’ve decided not to award week-by-week cumulative grades, as they could be confusing and also because we want to assess your contributions for the whole blogging period in terms of the qualities listed in the grading rubric.  You are welcome to consult an instructor in office hours or elsewhere for feedback about your blogging contributions.

If you have questions or need more information about a particular grade, you are welcome to contact me or one of the other instructors.