Reality Check: The True Size of Africa

Africa is unimaginably large, and not surprising why the cost to fly around the continent is relatively high.

The Inauguration of the 6th Grade Guest Speaker Series, and Poulet On The Grill

It is a privilege to teach at an international school with access to such rich resources.

The 6th grade has begun a Friday afternoon Guest Speaker Series, inviting members of the ISD community -- parents and staff -- to come in and share a personal interest, skill or experience, whether connected to their profession, or more an advocation.

Ali's pop was the first to visit with us. Mr. Ka shared his experience of making the Haj to Mecca earlier in the year. I think we all found it very interesting, from the history and significance of the Kaaba, to the challenge of locating a bathroom when you're surrounded by several million pilgrims!

Upcoming presentations will include the arts and music, sports, culture and the nature of relief work. All fascinating.

* * *

BBQ.

I'm still trying to figure it out, and through my small successes it's coming together, sort of.

I've got the coals figured out: Place a small pile of briquettes on the grill, and use the gas stove to get them lit up.

(I'm glad that there isn't a smoke alarm in the flat. Insert image of toubab Tod -- toubab here used not in it's most flattering connotation -- scurrying across the living room with a grate of red hot smoking coals, sparks popping -- an excellent segment for the movie Jackass 3.)

I then use the official Senegalese coal-fanning tool (there is one) to up the flame, and the coals roar. Excellent. So far, so good.

Well, let's stop there. The rest is embarrassing.

Dive! Plage N'Gor: Happy Birthday Gus! 10.14

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The Saalfeld Family -- Brigette & Mark, Gus (grade 5) & Ben (grade 8) -- are a wonderfully sweet family. They are together learning to SCUBA dive at the Nautilus Dive Center in N'Gor, and chose to celebrate Gus' birthday with a family dive. Gus invited me along, which I flatteringly accepted, with camera in hand.

Discriminating Taste 10.12

This taste discrimination experiment was the second of two designed to explore the nature of science generally, and the scientific method specifically. Here is the final report:

INTRODUCTION AND PREDICTIONS

The purpose of this experiment was to see if 6^th grade students were able to distinguish by taste the difference between three brands of locally available cola drinks here in Dakar, SENEGAL: Coca-cola, Magic Time Cola and Afri-Cola.

The class was mixed in their predictions. Most were unsure of the result.

PROCEDURE

The subjects for this experiment were 38 6^th grade science students attending the International School of Dakar. They are 11 and 12 years old, 19 girls and 20 boys, all good looking and above average.

Subjects were asked to compare the taste of two small samples of cola, served in small, plastic bathroom-style cups, to determine whether the samples tasted the SAME or DIFFERENT. Each student received three trials in succession. Between each sample, and between trials, subjects were instructed to sip fresh water, with the intent of cleansing their palettes.

In addition to determining SAME or DIFFERENT, subjects were also asked to provide a confidence rating for each trial: on a scale from 1 to 5, how confident are you of your response, where 5 means that you’re certain, and 1 means that you guessed.

Students designated as POURERS prepared all samples in isolation in the rear of the classroom, using a master list of subjects x trial x cola. EXPERIMENTERS worked directly with the SUBJECTS, guided and monitored their sampling, and recorded their responses.

The POURERS did not prepare their own samples. Instead, volunteer students prepared their samples from a master list kept hidden from the POURERS.

This experiment was double blind: neither the EXPERIMENTER nor the SUBJECT knew which brands of cola were being served. Actually, the sneaky teacher mixed up the colas bottles, and regrouped them only by number – cola 1, cola 2, and cola 3 – so that even the POURERS didn’t know what brand they were serving.

Three factors were randomized: the assignment of students to subject numbers; the assignment of the SAME/DIFFERENT conditions to trials; and the assignment of cola brands to cups. All this was done using a random number generator available on the internet at http://random.org.

Note the master data sheet, used by the POURERS, attached. Note also a sample subject response form, used by the EXPERIMENTERS, also attached.

RESULTS AND CONCLUSIONS

The results of our experiment are summarized in the top image above.

Based upon these results, we conclude the following:

· = Students are able to distinguish between the three brands of cola, but the effect is small, only about 60%.

· = The differences between boys -girls (about 1%) and homerooms (about 3%) are not significant.

· = Students who rated their response with a confidence of 5 did in fact perform more accurately, but the difference is very small, only about 5%.

· = Our results suggest that subjects were more accurate in judging differences than similarities, with the highest accuracy in the SAME condition 9-20% lower than the DIFFERENT conditions.

DISCUSSION

The purpose of this experiment was to investigate whether children are able to accurately discriminate among brands of cola drinks. In this case, we compared Cola-Cola with two less expensive generic brands.

Our results suggest that our subjects were able to distinguish amongst the three brands, but the effect was weak. There were no significant gender or homeroom class differences. It does seem that differences are more easily detected than similarities. The reasons for this are particularly interesting and worth exploring.

Dive! Plage Mamelles 10.9

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Photographed while snorkeling with Steve K. off Plage Mamelles. The water was less than ideal, with a significant surge, varying visibility, and strong surface-to-bottom thermoclines, indicating that the seasons are changing, and the great West African upwelling machine is beginning to roll.

Ethan Stroke Analysis 10.7

The above stills were pulled from HD video filmed while swimming beside Ethan in PE.