B session trainings: time is not on our side

Lautem, Timor-Leste

September, 2016

We’ve begun our B session trainings in the two eastern municipalities of Lautem and Baucau.  I drew Lautem this time, together with Julio and Fin, whom I’d trained with in the A sessions, and two SESIM trainers I had yet to train with this phase: proud Lautem son Mestre Bernardino, our top mathematics trainer and junior professor at the national university; and Mestra Mimi, one of our top chemistry trainers.  We’re staying in spare rooms at the home of Mestra Sandra, another SESIM trainer from Lautem, now in charge of the Green School program described in the last blog.  She couldn’t make it, but her family has been a great host.

Traditional sacred houses in Lautem, like this one in the capital’s central square, are both beautiful and practical. High, steep roofs shed rain easily and make great places for grain storage. At the top of each of four stout legs, just under the room, are large horizontal boards, which deter would-be rodent and reptilian food thieves.

Lautem municipality fills the far eastern tip of the island of Timor.  Three local languages are spoken in different parts of the district, in addition to the two official languages, Tetun and Portuguese, as well as a good deal of Indonesian.  A common phrase we hear in Tetun, the base language of our training, is: “In ours, we say …”, at once taking proud possession of their language while also teaching it to others.  Lautem has a reputation for valuing education.  Several local schools are always among the nation’s best in terms of test results, and I’ve noticed Lautem natives seem to crop up in high positions throughout academia; SESIM’s got 5!

By a fluke of scheduling, none of the 5 of us trainers here now were here for the A sessions, but it seems SESIM has risen to a level of organization and consistency such that the Lautem teachers got right to work without a hitch, pleased with another SESIM training.  We find the teachers generally eager to learn and full of creative ideas.

All the topics we cover in the B sessions are from the newly revised curriculum to be taught in the first trimester of next year, January through April.  Our first two B sessions are in September and October, long before exams in November, and the other two are in November and December, well after the exams.  Timor-Leste’s rigid, formal, high-stakes exams are a carry-over from Indonesia and Portugal.

Pratika topics in the mathematics section include sequences found in the lafatik winnowing basket, present in every home. You can see the series of figures on the base of this group’s lafatik: one lone hexagon, 3 in a triangle, 6 in a triangle, 10 in a triangle. We help them discover the formula for this sequence.
Here you see another sequence in the lafatik weave. Concentric stars have steadily increasing perimeters.

But, in an effort to make lemonade from sour lemons, part of SESIM’s curriculum revision was to create and distribute a large number of model exam questions related to the set of newly required pratika, and to help the Ministry of Education evaluation department incorporate similar questions into the national exams in 9th grade.  In an unfortunately accurate paraphrasing of the Field of Dreams:  if you test it, they will teach it.

The mathematics content for the B sessions spans the topics as always:  number systems, pre-algebra, geometry, statistics, and sequences.  The science content of the B sessions is around half physics and astronomy and half chemistry and geology.  I’m helping mostly with physics this time. I’ve done many of these activities hundreds of times in three different countries, yet I have still been able to learn new ideas here from watching the Lautem teachers do the pratika.  I have also been inundated with great questions and had to email my colleagues back in California for reinforcement explanation several times.

Frankly, there are too many pratika in the science B sessions.  Here is the line-up (I’m known as Gabriel or Gab here):


You can see it’s a packed week:  27 pratika to run through in five 7.5 hour days. (We keep lunch to strictly an hour, but the snacks often stretch to 20 minutes.)  Several of the activities are demonstrations, that is, the teacher does it in front while students just watch.  We trainers in turn often do that for the teachers, but it’s not ideal, because each teacher will have to do these demos themselves back at their school.  Each teacher really should have a chance to personally try everything, but it’s just not possible with the limited time.

(The teachers themselves often complain that we’re rushing things, and we have a great response for that: a few years ago Indonesia’s Ministry of Education radically changed the entire national curriculum, and gave not a single teacher training.  In other words, count your blessings.)

The truth is that teacher training, like life, is a compromise from start to finish.  We have a sweet, solid pedagogy that we do our best to convey, and we introduce a whole set of fabulous new pratika that are doable with simple materials and relevant to their everyday lives.  But with an average of an hour and 20 minutes for each, we can’t go very deep into many of them.

We passed out T-Shirts with SESIM’s motto in Tetun and English, courtesy of UNESCO Jakarta and our good funder KOICA.

To try and get a good balance, we choose a select few and spend a full two hours on them. On the other end of the spectrum, we pull off some of the demos in just 10 or 15 minutes:

  • Matter transformation: See how when we light this candle it burns away, never to return, whereas when we melt this candle with hot water, we can cool it again and it is still sort of a candle?  Ah: one change is chemical, the other physical.
  • Rotational motion: See how the rock on the string goes around and around at a certain speed, but then begins to spin faster when you pull it in toward the center? That’s what the theory says it’s supposed to do!
  • Buoyant force: See the plate floating?  Now see it floating lower when I pile on the rocks?  And notice the water level rise in the basin?  Great, let’s move on.

Of course, each of these concepts is the tip of a magnificent iceberg of knowledge.  It pains me to talk about buoyant force without mentioning Archimedes and his principle.  Since I was a child I’ve been star-struck by that concept, and even named my dog after the venerable old Greek.  But to merely state the concept in Tetun requires two cumbersome sentences, and to treat it in any sort of meaningful way requires an hour minimum of playing with floating and sinking and forces, just to get everyone on the same pleasant page.  (If you’ve forgotten or never heard it, here it is in English:  the buoyant force equals the weight of the displaced fluid. Like poetry, eh?  Try to put it into another language you know.)

Measuring density is one pratika we spend two full hours on, but we still don’t do it as well as we could.  We do the standard routine of measuring the mass and volume of several objects, calculating their density, and then checking to see which of them float and which sink in water.  All the ones floating should have densities less than 1 g/ml, since that’s water’s density.

We only have two electronic balances, and will soon be procuring and delivering a single one to each school. It’s not ideal, but with creativity and patience, many fine pratika can be carried out.
Devils reside in the details when measuring volume using water displacement, and teachers must find the meaning of each line on the measuring cup’s wall.


Just last year I got the chance to do density right:  the class is divided into 6 groups, and each group gets 5 baggies, each with several pieces of a single material.  Each group receives the same 5 materials in their baggies, – for example  steel, wood, cork, potatoes, PVC, marbles, etc. – but different amounts of them,   Each group finds the mass and volume of each of their baggie’s contents, and plots the results on a common graph pasted up in front, x=mass, y=volume.  The dots are all over the place, but slowly it is discovered that (except for the sketchy outliers!) the dots describe straight lines of different slopes, all leading to zero.  Thus the formula for density, with the queer ρ equaling m/v, is laid bare in front of the whole class; it’s something like the opposite of a conjurer’s trick, in that everyone ends up in the know.  See Don Rathjen’s brilliant pratika: Plot the dot.

But we decided not to put that particular piece of pedagogic profundity into the junior-high curriculum here, one, because the complex activity takes 2+ hours to do with a good deal of set-up time as well, and two, because most teachers themselves don’t yet grasp density.  Instead we compromised. We lead the teachers through this lesser activity, which still has them coming to terms with measuring both weight and volume, a first for most of them.

The reality we embrace at these trainings is much the same as the reality the teachers face each day in their classrooms: time is limited.  In the future, we hope to do more in depth sessions with teachers, for example spending a whole day on a single concept with several pratika from various angles.  Right now our priority is introducing the teachers to our pedagogy and presenting each pratika in some form.  So we let them chew well on one or two concepts per day, and trot them through the rest.  They smile and laugh a lot, and the evaluation results remain extraordinarily positive, so we must be doing something right.


We constructed dynamometers, (spring scales) with rubber bands and then calibrated them. It turns out that rubber bands follow Hooke’s law, F=kx, though some are more lax than others.
This is the popular stomp rocket pratika, developed by my student and me in California in the late 90s. A paper tube rocket hugging the end of the tube goes flying off like a dart when you stomp on the attached plastic bottle. This pratika touches on nearly every basic concept of mechanics. At junior high level, we keep it mostly qualitative, but in high school we apply simple motion equations and calculate changes in pressure using PV=nRT.




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