168 – Feedback and Chi Square

Today in honors biology we worked on leaving feedback and displaying our posters for the CER model we did earlier in the week. Next week the kids will use the Post-It note feedback to reflect in their journal about whether they could incorporate feedback into their revisions if they were to make them and if not, why?

In AP biology we moved into working on Chi Square which is a statistical method used frequently in the course. A short explanation by Paul Andersen about it led to a Q & A about real world applications. The students then did the old M & M chi square activity, looking at bags of the candy in comparison to the Mars company’s proportions. The Chi Square calculation and null hypothesis generation (in particular) stumped kids this past year and this activity did a nice job to rectify that. 

As an aside, my ecosystem jars ammonia levels rose too much and killed off my animals. I had to do some science today to figure that out and how to remedy that. The shrimp and snails are hardy, but I was at fault in expecting them to suddenly adapt to the small container. I will monitor the water quality for a week and introduce some nitrifying bacteria. I’ll also let the plants modify the ecosystem before adding animals. When I do, the snails will go first and then the shrimp. I may even use smaller shrimp to prepare for a larger respirator. I was not happy about the shrimp and snail deaths but it led to some patient thinking and a revision of the methodology. 

 

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