Statistics test three

MS 150 statistics test three includes some material that is not subsequently covered on the final examination. The material that is not covered are normal curve calculations that provide a foundation for the t-distribution and subsequent consideration of confidence intervals. Some of the student outcomes on the outline must be assessed by test three. Course learning outcomes 2.1 and 2.2 are assessed during test three.

Test three consisted of 14 questions based on a small 12 item data sample. 73 students sat for test three. The fourteen question test was worth 15 points, two for the final question which involved citing a confidence interval. Overall performance was an average of 71% on the test The median test score was 80% correct.

The first three questions were basic statistics that the students calculate on almost every quiz and test.

Questions four and five cover material the students have not seen since midterm about a month ago, these are effectively a measure of retention of material for which the students are not likely to have studied.

Questions six to nine involve normal distribution calculations. Ten has the students calculate the standard error of the mean. Eleven to fourteen are the newest material, the students first encounter with a 95% confidence interval using the t-distribution.

Qstn	Chap	Topic	n corr	%corr
1	1	n	71	0.97
2	3	mean	71	0.97
3	3	sx	70	0.96
4	3	z-score	36	0.49
5	3	infer	31	0.42
6	7	normdist	59	0.81
7	7	normdist	25	0.34
8	7	normdist	40	0.55
9	7	norminv	58	0.79
10	8	stand err	59	0.81
11	9	deg free	61	0.84
12	9	tc	59	0.81
13	9	margin err	42	0.58
14	9	CI	36	0.49

Performance on questions one to three averaged 97%.

Questions four and five, which were unannounced and covered old material from before the midterm saw a 46% success rate. Retention of knowledge remains elusive over any span of time. Nine of the 36 students who answered four incorrectly omitted parentheses in the z-score formula. Students have access to formulas during the test, thus this error is particularly puzzling. The other 27 incorrect answers showed no discernible pattern.

Course learning outcome 2.1, normal distribution calculations, had a 62% success rate. The easiest problem, using the NORMDIST function to find the area to the left of a data value had an 81% success rate. Students are able to make a basic single calculation which requires no special set-up or analysis.

Questions seven and eight required more careful analysis. Question seven asked for the area to the right of a data value. This requires finding the area to the left and then subtracting that value from one. The dominant incorrect answer was simply the result of the first step: finding the area to the left of the data value.

In light of the above paragraph, the improvement seen in number eight is somewhat puzzling as eight required finding the area between two data values. This is actually more complex than number seven, however the wrong answer in number seven can be used to derive the answer to number eight. Thus getting seven wrong was not necessarily an impediment to getting number eight correct.

Question nine required use of the NORMINV function to find an x-value from the area to the left of x. This was a simply calculation and saw a 79% success rate. Bear in mind that errors in questions two or three prevent obtaining the correct answers for problems involving both the NORMDIST and NORMINV function. Five students answered two and/or three incorrectly.

Question ten, calculating the standard error, which is course learning outcome 2.2, saw an 81% success rate. This calculation will appear on subsequent quizzes and the final examination, thus success rates should theoretically improve.

Questions eleven to fourteen test course learning outcome 2.3. This material will appear again, including on the final examination. While the average success rate is 68%, the questions are a chain of sequential calculations where answering a preceding question incorrectly usually prevents answering subsequent questions correctly.

Overall performance by course learning outcome is summarized in the following table:

CLO	Perc
2.1	0.62
2.2	0.81
2.3	0.68

Current discussion at the college centers in part on what is an acceptable rate of success and whether a 60% D should be a passing grade. Is a D really an F? I would also ask whether the standards applied to the individual student apply to item analysis of a group of students. The students are still be graded on the traditional scale, but what are the acceptable success rates for student learning outcome?

Historically overall averages are similar to those seen in the CLO table above.

SLO	Fa 05	Fa 06	Fa 07	Sp 08	Fa 08	Sp 09	Fa 09	Sp 10	Fa 10	Sp 11	Avg
1.1	0.6	0.92	0.82	0.78	0.82	0.94	0.96	0.74	0.44		0.78
1.2	0.61	0.56	0.6	0.83	0.84	0.75	0.79	0.55	0.7		0.69
1.3	0.89	0.91	0.87	0.9	0.8	0.86	0.93	0.74	0.95		0.87
1.4			0.5	0.67		0.82	0.59	0.73	0.52		0.64
1.5						0.77	0.52	0.75	0.79		0.71
2.1			0.61	0.71		0.61	0.45	0.71	0.19	0.62	0.55
2.2			0.74	0.84	0.84	0.87	0.91	0.64	0.78	0.81	0.80
2.3	0.65	0.79	0.4	0.66	0.85	0.67	0.73	0.55	0.65	0.68	0.66
2.4	0.7	0.69	0.64	0.36	0.56	0.55	0.55	0.46	0.83		0.59
2.5			0.68	0.55	0.63	0.43	0.56	0.46	0.71		0.57
3	0.74	0.61	0.73	0.8	0.79	0.63	0.69	0.7	0.76		0.72
3.1	0.95	1.61	0.9	0.91	0.95	0.85	1	0.79	0.88		0.98
3.2	0.91	0.37	0.93	0.84	0.85	0.87	0.92	0.79	0.86		0.82
3.3	0.49	0.69	0.56	0.66	0.44	0.38	0.47	0.55	0.58		0.54
Avg	0.73	0.79	0.69	0.73	0.76	0.71	0.72	0.65	0.69	0.70	0.72

Spring 2011 performance on 2.1, 2.2, and 2.3 are in line with historic averages and are, if anything, potentially slightly stronger. The terrible performance seen on 2.1 Fall 2010 has been strongly reversed.

I would be remiss if I did not note that stability in the basic outline and assessment process choices over the past six years has provided the ability to look at success rates by CLO across that span of time. The ability to provide coherent assessment data that is comparable across this time span is, for me, a form of validation of the usefulness of simple item analysis to determine the level at which learning is occurring.

This data also, at least for me, provides a basis for discussing what is an acceptable level of performance on an individual student learning outcome and on overall average performance levels. Over the past ten terms overall performance per term is bounded between an average 65% to 79% success rate as measured by item analysis. Given that the margin of error for the mean at a 95% level of confidence is near nine percent at present means that specifying, for example, a 70% success rate could still see term averages as low as 61% on a purely random basis.

The upshot is that looking at one term is statistically insufficient. One term at 61% would not, at least for statistics, mean that a long term average of 70% was not being maintained. Thus saying that all courses will achieve 70% success rates (or any other rate) for all outcomes across all terms is simply unrealistic.

Spirit Week

Spirit began with crazy dress day on Monday.

Seen in the cafeteria, Mayleen sporting the deadliest Pippi Longstocking hair style.

Tuesday was cross-dressing day. By coincidence the Upward Bound students were also on campus. The director of Upward Bound joins in a group photo with some, uh, lovely Chuukese co-eds and a bearded old lady.

Culture day is really the highlight of Spirit Week, the day that is visually like no other Spirit week at any other college on the planet. Mylinda displays her Chuukese heritage adorned with Asplenium nidus about her waist, Cordyline fruticosa around her midriff, and Nephrolepis ferns on her arms and head.

A Pohnpeian wearing a traditional koahl, using a kiam to carry his books. A scene from early in the 20th century.

Culture is a moving target, an evolving, living and breathing entity. Debra wears what might now be considered a classic look from twenty-five to thirty years ago.

Outer island Yap.

Renee wears church traditional wear.

I too attempted to find something traditional to wear.

The Bridge

Running. Sun Behind. Bridge ahead. Three orbs up. Winded. Pushing. Cross the water. Cross wind. Far Side. Turning. Back. Into the face of a shining sun.

A run to the bridge first swings up past the PICS track
Geolocation

The run to the bridge began as a bachelor in 1994 from an apartment at the bottom of Elenieng street. That first run was exploratory - a run to see the terrain. When I saw the bridge I knew that was my turn-around. Only when I reached the near side of the bridge did I realize that a run to the bridge ought to at least be to the middle of the span. To the center of mass if not also the center of gravity. Equidistant from either beginning of the bridge.

A run to the bridge heads down from capitol hill towards the intersection of Kaselehlie and Elenieng
Geolocation

At the middle of the bridge I realized that if one has made the effort to get to a bridge in life, then one should, at the very least, cross the bridge and experience the other side. I cross fewer bridges now than I did in my youth, and I cross them more cautiously than I did then.

The view from the bridge looking south
 Geolocation

I ran to the far side of the bridge, crossed the Nett Point circumferential road, and then turned around. From that first day on, a run to the bridge meant a run to the far side. Nett bridge far side. NBFS.

 The view from the bridge looking north, Paipalap in the distance

Four years later my sister-in-law, my wife, and I would move to a home beyond the bridge in Nantipw-Lewetik, Nett. Once or twice a week I would run home from the college in Palikir, a distance on the order of fourteen kilometers. The bridge marked the start of roughly the final 1600 meters, a final mile.

The first time I ran the route I arrived after an hour and forty-two minutes. I knew I could easily bring that down under one forty, but I was uncertain whether under one-thirty was possible for me. For a runner, a 1:29:59 counts as "under one thirty."

I ran a number of runs in the low thirties when I managed to put my form, pace, and stamina together to notch a one-twenty-eight. Now I was looking at one-twenty, but putting together that one-twenty-eight was tough enough that one-twenty appeared unreachable.

In 1999 I learned that the bridge has a name, the Dausokele bridge.

Each run home from the college passed the Pohnpei state hospital. In May 2000, my son was born there. Two days later, with mother and child still in hospital, I ran past the hospital where my first born was sleeping.

My splits into Kolonia had been unbelievably fast for me - all under an hour. Running through Kolonia, I kept thinking I had to crash, I was too far above a pace that would get me to the bridge, let alone the last mile. As I passed the hospital, I realized something special was happening. Magic was happening. As the hospital slid past me, I realized this was a once in a lifetime evening, I would never run this run again. My bridge split confirmed this for me, and I flew home in a never repeated 1:15:15. I spent that night in the hospital holding my newborn son.

Seventeen months later my daughter was born in the same hospital. Two days later my son fell ill. I spent six days with him around the clock in the open children's ward. The nights were the longest, he was weakest in those small hours in the middle of the night. I knew that outside the moon was shining on an empty bridge.

I ran to the bridge when Heinrich was admitted to the hospital, racing the setting sun, to try to reach the bridge  before the sunshine vanishes from the deck of the bridge. I kept pushing harder. My body unwilling, but my mind telling my body, "You are not dying yet, fight on." I won my race that evening and burst out of the shadows into the last light of the sun on the deck, but Heinrich was lost to us.

I ran to the bridge when Benson was admitted, leaving me lost in the thoughts of the terrible terror of cancer.

I ran to the bridge when Harvey was in, struggling to breath. I pushed deep into my own oxygen debt. Faster. Faster. I am not breathless enough yet.

In early February the early evening sun shines straight down the lengthwise span of the bridge. Eastbound the sun is behind, the forested slopes of Nett Point ridge line aglow with the golden light of the late afternoon tropical sun.

On a race for the sunshine, this is the first view of the bridge
Geolocation

Westbound is directly into the scorching sun, still searingly hot. A stellar nuclear fusion furnace directly behind my three ascending and descending spheres, lit from behind like sunward planets. The only wind a solar wind.

On a lazy, sunny afternoon when the heat and humidity cause the fan and a nap on a cool tile floor to seem an appealing activity, the bridge beckons me. Calls out to come and race for the sunshine on the deck.

Sunshine on the deck of the bridge

Taking a loss on an issue at work, I try not to bring it home. I bring it to the bridge. Running amidst traffic, uneven surfaces, in the road, the wind, and the sun is too complex too remain focused on the matters of the day. They melt, dissolve in the heat, fall to the ground, and dissipate. Inbound Nett school I realize the shadows are long. The race is on, the race for a shadow being cast on the deck, a race for sunshine.

Geolocated photographs

Recording an image of a plant and the location of the plant has meant hauling around a camera and a GPS, and then later adding in the geolocation information to the photo. Until now.

No doubt about the location of an image when the extended image data includes the latitude and longitude.

The FujiFilm FinePix XP30 GPS, satellite enabled. The real fun is that the camera can "track back" to a stored photo location. I will be wrestling with image sizes, however. 640 x 480 is not directly available in shooting mode.

The smallest image is a 1920 x 1080 pixel 16:9 ratio image. I know the image appears smaller, but click on the image to see the original size. And to think I first utilized 200 x 150 pixel images from a one thousand dollar Sony DSC-F1 in 1998.

Pwisehn Malek after 1998 El Niño grass fire

Now for a quarter of that cost I can shoot 14 megapixel geotagged images. Change is the constant.

Post-script learnings: If uploaded from Panaramio into Panaramio, the geolocation information is retained and Panaramio places the image in Google Earth. If one uploads to Picasa from the Picasa web site, the geolocation information is NOT retained. However, if one uploads to Picasa from Picasa desktop, then the geolocation information is uploaded with the photograph. The later process also allows one to resize on upload.

Uploading from Picasa to Picasa resized the 1920 x 1080 to 912 x 513 in Picasa, thought the properties still show the original size. Uploading from Picasa desktop software to Picasa with the options set to 640 yields a 640 x 360 image in Picasa online. Picasa no longer counts images under 800 pixels against one's storage space, so there is an advantage in staying under 800 pixels. 

Note that the 912 x 513 can be seen at its original 1920 x 1080 by clicking on plus sign that opens the image using Flash player. Flash includes a zoom control so one can further zoom and scroll when the image exceeds your monitor size. The 640 wide image is shown at full size and cannot be enlarged further by Picasa.

Material Culture

Material culture presentations in SC/SS 115 Ethnobotany.

Jackleen presents a coconut husk scrubbing implement called a dipoanihd in Kitti, Pohnpei. The dipoanihd is used not to clean sakau of dirt per se but rather to remove fungal and other growths that would add an extremely bitter taste to the sakau.

Vanessa gestures to indicate the actual size of a dil kahlel, a torch made of coconut leaves which is used to attract flying fish during night fishing. Flying fish season is March, hence March is also known as kahlek - dancing month. The men dance with their torches in their canoes out on the water while the women prepare land based starches at home. When the men come in a late night family feast is in order.

A dok kemelis used for pounding hard taro. While the men "dance" in their canoes during March to catch flying fish, the women pound giant swamp taro getting ready for the special meal which will follow the fishing.

Angelo brought a model of a pelek from the library, a copra grinding stool. As noted in class, once the material culture of a society is only objects in a library, then those objects have lost their cultural meaning, they are but dead things on a shelf, no more imbued with life than the books they sit next to. That said, the pelek remains in active use across Micronesia. As to whether a full sized one can be carved from a single piece of wood like the model above, a student from Yap noted that she had seen such a coconut grinding stool in Yap.

A ngarangar for the sakau ceremony. Prior to becoming a ngarangar the cup is known as a poun dal. Once sakau is in the ngarangar the cup is referred to as a kohwa. A ngarangar is special and is not used for anything other than sakau. A ngarangar may be handed down through a family. The ngarangar unites a family around the sakau cup both in the present and across the generations, across time. Tremendous symbolism surrounds the ngarangar.

Betsyna brought in a basket called a kiam used for food from the uhm (rock oven) such as pig, yam, breadfruit.

Anthony holding an uken laid model from the library. More culture on a shelf. In earlier years no student needed to "raid" the library to have something to present. Whether the present plethora of library based items is a sign of material culture loss or simply students not making the effort to bring in items remains unclear to me at this time. For some students growing up in Kolonia there may be a real dearth of actual culturally relevant items. I expect I shall have to ban library based items and see what happens.

Annjanette of Yap proper wears the marfaw'. The marfaw' is given to a girl after menarche and symbolizes that she is now a woman. When a young woman wears the ong gal' formal grass skirt, then she must also wear the marfaw'. She need not wear anything else above the waistline, but she must wear her marfaw'. In traditional times the marfaw' was made from hibiscus, with red being the traditional color of the marfaw' The marfaw' is a symbol of coming of age for a young woman in Yap.

Grass skirt names of Yap

Very young girls start off wearing a skirt called a lebwu' made from soft betelnut leaves. Once she reaches puberty she can wear the fadilap made of coconut, banana, or fern leaves. The ong gal', seen above, is worn only for special occasions such as dances. Elvira, above, wore her ong gal' for her first communion in church. When the ong gal' is worn it is worn with the marfaw'. A woman may also wear a lei. Old women wear a grass skirt called a buch made of old brown banana leaves.

Isabella brought in a lap', one of the forms of lei that a dancing women may wear. The traditional colors are red and yellow, occasionally purple. The green in the lap' above is considered somewhat non-traditional. The yellow colors are produced from the roots of Morinda citrifolia, the reds are produced by adding wine to the yellow dyes from M. citrifolia.

Isabella.

Mylinda brough a canoe from the library. She noted that while her grandfather still occasionally uses a canoe, she and her parents generation do not. They use outboard motor boats.

Syleen presents the nipwepwe - the Chuukese love stick - which is now little more than a curio sold to tourists, devoid of any real meaning or use. The nipwepwe almost seems to symbolize the changing social structures surrounding mate selection in Micronesia.

To be charitable, Jayheart is confused at best, presenting a highly stylized work of art based on the Chuukese nipwepwe as some sort of Pohnpeian spear. It is not. Cultural knowledge loss and devolution are quite real.

Jasmine notes the importance of Hibiscus tiliaceus in the sakau ceremony. The inner bark, seen above, may be called koht, although there was some discussion of this. The more commonly used term is that which refers to the whole plant - kohlo.

Melinda brought in a mwarmwar made from Microsorum scolopendria. This protects a dancer who is dancing outside of their kousapw - their land unit - from spiritual harm.

Judyleen holds forth on the padil - used for dances, moving canoes and potentially as a weapon. The padil is a paddle with a sharpened end point. This always leads to the question, "Which came first? Foreigners with paddles or the padil?" If the latter, what was the padil called prior to Western contact, as padil is surely the word paddle.

Juanita brought in a tuhken lup - a stick for beating laundry.

Refraction and Reflection

Laboratory ten began with an investigation of the relationship between the distance of an image behind a mirror versus the distance of the object in front of a mirror.

Sinforsa works on the apparent depth of a penny

This term I lined up all of the beakers, the bucket, and large graduated cylinders, from zero water depth to 50 cm water depth.This seemed to work well, especially if the students started from the deepest penny.

LillyAnn and Brilinda measuring the image distance in a mirror.

Bersin working on the apparent depth of a penny in water.

ShirleyAnn works with a figurine. She postulated that the image distance would be less than the object distance, thus the slope would be greater than one. The Ardos-Alfons theory stated that the object distance is equal to the image distance.

Angie confers with Nancy

Tracy Ann

Silver Rose

Patsipa and Tracy

Peter

Johnson and Jeremiah