danaleeling

To demonstrate that relative frequency is probability and to show that sample values can only lead to conclusions about what the population values are not, not what they are, a mix of two colors of marbles were used.  Spring 2025 35 blue and 15 green marbles were put into a cloth bag. 14 students were present at the time of the draw, each blindly drew a single marble. The result was 11 blue and 3 three green for a 79% and 21% relative frequency. The actual relative frequencies were 70% and 30%.  Fall 2024 a mix of 40 blue and 12 orange marbles was used, 77% and 23%. The draw by 21 students was 13 blue and 8 orange, 62% and 38%.   Fall 2025 30 blue, 20 orange, and ten white marbles were placed into a cloth bag. 18 students each selected a single marble.  Some of the questions posed ahead of the marble tally included: What percentage of the marbles in the bag are blue, white, and orange? Can I know the number of marbles in the bag from the ...

Force of friction ran on a cold open, one-by-one mentoring start. A single student arrived by 8:00, instruction was one-on-one. No opening lecture or explanation. As students trickled in, each was either started on measurements or added as a partner to an existing solo experimenter. Initially gathered data during the demonstration phase was echoed to the white board. Austin and Yonard measure the effect of weight on the force of friction. Vandasia and Tayshaun measure the effect of weight on the force of friction. LizxyAnn and Bennie test the effect of grit size the force of friction. Tommylee worked solo and found that in the force range where the green and blue spring scales overlap they do not produce the same result for a given load. To think to check for this possibility is deeply insightful. He understood the implicit assumption that the scales were both accurate, questioned that, and found that they were not. Absolutely...

Opened with the black stone/white stone example of a 50/50 probability. Then did ten pennies passed out to all students. Followed by multi-sided dice examples. Time was tight, perhaps too tight. The opening, based on Exodus 28:30, has to be kept short, brief  and light. Or skipped entirely.

The bus arrived at around 15:50 Coleus scutellarioides had come up again in the healing plants presentations. The class began at the Ficus prolixa before moving onto Syzygium aromaticum and the Araucaria columnaris. Faithjewel rubs Cinnamomim verum Vinola takes photos and notes, as does Ashley behind her. Cinnamon! Vinola, Nicole  Ashley, Tommylee leaving the Myristica fragrans. Arrival at he Eucalyptus deglupta was 16:20, a little later than ideal. Perhaps too much time at the Ficus prolixa or the Myristica fragrans. The reversed order of having the field trip ahead of the gymnosperm, timber, and spice trees slide deck worked against moving more quickly. There was nothing to reference back to. At 16:32 the class arrived at the Agathis lanceolata. The Agathis lacked any recent resin. The van arrived adding to the time pressure. Piments dioica was quickly covered. The Calophyllum inophyllum was only pointed at ...

This term the measurement of the downslope force was improved by tying a loop of jute twine to a post. Board ahead of RipStik run Ahead of class my mass and the mass of the RipStik were measured. The twine was also already prepared, attached to a post on the west side about halfway up the 21 meter run. The spoed trap was kept on the slope at the same length as last week: 1.8 meters. Data after the run. The downslope time was stopped at top of speed trap. By keeping the speed trap on the slope there were no losses to friction. The change in momentum took 15.411 seconds for 21 meters minus 1.8 meters, a 19.2 meter run. Five timers were deployed on the 1.8 meter on-slope speed trap. Four stopwatches and a cell phone. The median time was used in the velocity calculation.  Spreadsheet For g, which wasn't strictly necessary, the median time of experimental results was used in keeping with the spirit of the course. The new spring scale arran...

A ten meter distance was marked off in front of the south faculty building ahead of class. At 08:40 I started making runs and gathering data.  Online metronomes were used after the eighth run to target gaps in the data. Class was a cold open on the sidewalk. Attendance was whomever showed up. After run 15 we returned to the classroom.  There the data was brought up on the Smartboard. Spreadsheet The extra duration in data gathering improved the sense of scatter. The correlation will come in at 0.87 and a coefficient of determination of 0.76. 

As with all of my blogs, the audience for this post is a single person, me. I use blogs as notes I can consult in the future to determine how I accomplished something, and provide a place to record formulas I used to solve particular problems. In this case I needed to connect grade exports from Moodle to class exports from MyShark to produce a list of students on early warning. As the target audience is my future self, these notes are necessarily abbreviated and may be missing steps that I know intuitively. That said, this might benefit someone somewhere when dealing with related complications. I needed advisor information for each student which is only available from an extended student data export in MyShark. I also needed grades from the Grades: Export menu in each course. Note that the export menu link is the same except for the course ID, so link editing can jump one from one export screen to another directly. If a course has multiple sections, then Groups have to be previously se...

This term a Thursday holiday turned the banana leaf marble ramp laboratory into a Wednesday demonstration using a Hot Wheels car and track . Rather than do the smorgasbord of equations approach of spring 2025, Friday was used to replicate the Wednesday demonstration but used the RipStik on the sloped sidewalk. Three heights were set up with vertical drops of 11 cm, 28 cm, and 37 cm. Eleven centimeters was on the pillar base. Twenty-eight centimeters was at the bottom of the post. The nuts actually proved useful in tensioning the line. Thirty-seven centimeters was on top of flanges. This measurement has come in at higher values in the past. Fall 2024 the height from 21 meters was measured as being 0.7 meters or 70 centimeters.  The first double set corresponded to the 11 centimeter drop. Twenty-eight cm Lines hooked on a nut to clear the sidewalk. Based on an image from fall 2024 , the launch this ...