The last class of the course. The lab reports go up on the walls, the data tables come out on the benches, and everybody explains their work to people who are going to ask about it.
This is not a presentation evening with an audience that claps. It is the part where somebody who was not in your group asks why you chose that limiting reagent, or which way your errors pushed, and you answer.
The situation
You have spent a semester producing work that only you fully understand. Today that stops. The room is arranged so that everybody presents and everybody questions, and the two halves are marked together, because explaining and defending are the same skill seen from two sides.
Nothing new is built for this. No new experiment, no new calculation, no new poster produced the night before. You are presenting what you already have, which means the preparation is entirely about selection and explanation rather than production. If you find yourself making something, you have misread the task.
What you present
1. Your work from The Water Report, in five minutes, spoken, with your data table in your hand rather than on a slide behind you. Cover four things: what you measured, how good the measurement was, what the published record said, and where the two disagreed.
2. One earlier investigation or task of your choosing, in two minutes. Choose the one where your thinking changed most, not the one that went most smoothly. A percentage yield of 103.8% that made you go back and find out why is a better two minutes than a yield of 98% that came out as expected. A prediction you got wrong in Building the Activity Series and then explained is worth more than one you got right by luck.
3. A career panel. One role connected to the chemistry in your work. The curriculum’s own examples are pharmacist, forensic scientist, chemical engineer, food scientist, environmental chemist, occupational health and safety officer, water quality analyst, and atmospheric scientist — and yours might be a lab technologist, a water operator, a quality control analyst, a pharmacy technician, a materials scientist, a science teacher. What does the work actually involve day to day, and what education and training does it take to get there? Two minutes.
4. A scientist panel. One person who contributed to a field this course touched. The curriculum document offers Carol Ann Budd, Edgar Steacie, Raymond Lemieux, Louis Taillefer, and F. Kenneth Hare as starting points, and you are free to choose someone else. Find out what they actually did, from a source that says where its information came from. A name is not a summary, and a one-line label copied from a search result is worth nothing here. Two minutes.
The questioning
Every presenter answers at least two questions, and every student asks at least two questions of other people. Both sides are marked, and half the marks are on the asking side of the room.
"I don't know" is a good answer when it is finished
Nobody expects you to have an answer to everything about your own work, and pretending is the only thing that will actually cost you.
A weak answer: “Um, I’m not sure.”
A strong answer: “I don’t know. My data can’t distinguish those two explanations, because we only ran one trial and never reached constant mass. If I repeated it I’d dry to constant mass and see whether the excess disappeared — which would tell me it was water rather than unwashed salt.”
Same three words at the front. The difference is that the second one says what you do not know, why your evidence cannot settle it, and what would. That answer earns more than a confident guess, every single time.
Good questions to ask other people, if you are stuck for one:
- Which way did your largest error push your result, and how do you know?
- How many significant figures is that number really entitled to?
- What would have made you abandon your prediction?
- What is the weakest measurement in your data?
- What did you control, and what could you not control?
- If you had one more class, what would you measure?
- What would somebody who disagreed with your conclusion say first?
How it will be judged
| What I am looking for | Level 3 sounds like | Level 4 sounds like |
|---|---|---|
| Explaining the work | Clear, accurate, in the right order | Pitched at whoever is standing there, and it lands with all of them |
| Quantitative honesty | Quotes numbers with units | Quotes them with the right number of figures, and can say why that many |
| Uncertainty | Mentions sources of error | Names the direction each one pushed, and which dominated |
| Language | Uses the correct terms | Uses them and can restate any of them plainly on request |
| Answering questions | Answers accurately | Distinguishes what is settled from what is not, and says which is which |
| Asking questions | Two relevant questions asked | Questions that made a presenter think, rather than questions with known answers |
| Career panel | A real role, correctly described | What the work is actually like, and what route leads to it |
| Scientist panel | A real contribution, correctly attributed | The contribution explained well enough that we can see why it mattered |
What sinks an otherwise good showcase
- Reading from a page. You did the work; you already know it. Notes on a card for the numbers are fine, a script is not.
- Hiding the result that did not work. It is the most interesting thing on your bench and everybody in the room has one. The yield over 100%, the titre you had to discard, the prediction that failed — those are the two minutes worth listening to.
- A number with no unit, or with six figures from a balance that gave you three. In this room, at this point in the course, that is not a small thing.
- “Sources of error: human error.” By now you know that a limitation is something about the method that survives doing everything perfectly.
- A career or scientist panel copied from the first search result, with no source and no sign you understood it.
- Vanishing during the questioning half. Half the marks are on that side of the room, and a room where nobody asks anything is a room where nobody has to defend anything.
Afterwards, and before the course ends, write Final Reflection in your Chemistry Journal. It is the entry I read first.
Curriculum connection
A1.11
communicate ideas, plans, procedures, results, and conclusions orally, in writing, and/or in electronic presentations, using appropriate language and a variety of formats (e.g., data tables, laboratory reports, presentations, debates, simulations, models)
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A2.1
identify and describe a variety of careers related to the fields of science under study (e.g., pharmacist, forensic scientist, chemical engineer, food scientist, environmental chemist, occupational health and safety officer, water quality analyst, atmospheric scientist) and the education and training necessary for these careers
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A2.2
describe the contributions of scientists, including Canadians (e.g., Carol Ann Budd, Edgar Steacie, Raymond Lemieux, Louis Taillefer, F. Kenneth Hare), to the fields under study
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