TA grading notes
While we do want you to grade the first experiment on completeness, we'd also like you to give the students some feedback on what they've done to let them know what's being expected of them in the future. To that end, here's a (non-exhaustive) list of things to consider when looking at the assignments.
Keep in mind that the entire assignment is worth 2 points, so slight omissions in responses should not result in deduction of points. Give 2 points if the work is complete and mostly correct. Give 1 point only if there are significant mistakes or omissions. Give 0 points if the work does not represent a meaningful attempt or if nothing was submitted.
Did the student include a picture of their ruler?
Does their procedure for making tick marks seem reasonable?
If not, give feedback on why. Was it too arbitrary? Hard to reproduce? Done sloppily?
Were the measurements of the ID card reasonable?
How was their assessment of uncertainty? Presumably the Z dimension (thickness) will be hampered by the resolution of the system the most.
Did the student come up with reasonable ideas for systematic uncertainties? Note that they don't have to definitively be a cause of uncertainty, but they should be plausible.
“The length could change due to heating from my hand” is an example of something just on the edge of plausibility. Technically true, but extremely unlikely unless they've got very hot hands or they're making a very high precision measurement. This is a case where the student would be given credit, but you might make a note on the low likelyhood of relevance.
“My ruler seems to be bent or bowed” is a decent example; easy to assess and very likely to affect measurements.
“My markings might not be uniform” is also a good example
“Quantum uncertainty might suddenly make my ruler shorter” is not a good prediction; it sounds science-y but is utterly implausible.
Did the student propagate uncertainties properly for a multiplicative quantity (i.e. did they add relative uncertainties)?
Did they justify either including or excluding some uncertainty in a plausible way?
The volume calculation could neglect the uncertainties from the x and y components, because the relative uncertainty in the z component will be an order of magnitude larger or so.
Did the students try to make proper comparisons with the three hypothetical classmates?
As an example, the $t'$ statistic for Wynn and Omar's area measurements is 0.8, so they would be in agreement. Leslie and Omar's $t'$ for area is 1.2, which is inconclusive.
If a student makes math errors that lead them astray (e.g. forgetting the square root) but interpret the derived $t'$ statistic properly you should give them credit, but note where things went wrong if you are able.
Was the student's improvement suggestion reasonable?
A half-baked answer like “I would measure better” or “I would measure more times” isn't sufficient.
Were the questions for other classmates sensible? Again, completely surface-level things like “Did you do it wrong?” are insufficient here.