Project Work and Laboratory Assessment
What you must command
This domain tests how you plan, execute, record, and report experimental or project work. You must understand the structure of a technical report (aim, apparatus, procedure, observations, calculations, results, discussion, conclusion), the importance of calibration and repeatability, safe laboratory practice, error analysis, and the presentation of data in tables and graphs.
Traps that appear in questions
- Calibration: instruments must be zeroed and calibrated before use; neglecting this invalidates results.
- Repeat readings: take at least three and report the mean with the spread.
- Graph plotting: label axes with quantity and unit, use a sensible scale, and plot the independent variable on the x-axis.
- Error sources: distinguish systematic (offset, calibration) from random (fluctuation) errors; averaging reduces random but not systematic error.
- Significant figures: the result cannot be more precise than the least precise input.
- Safety: guard interlocks, emergency stops, and personal protective equipment are non-negotiable.
Worked rule of thumb
When reporting a measured quantity, express it as mean ± uncertainty. Example: three readings of a diameter are 25.02, 25.04, and 25.00 mm. Mean = 25.02 mm; range = 0.04 mm; a simple estimate of uncertainty is half the range, 0.02 mm, so report 25.02 ± 0.02 mm. If a systematic zero error of −0.01 mm is known, correct all readings by adding 0.01 mm before averaging - averaging alone will never remove it.
For a graph, the slope often yields the physical constant of interest; calculate it from the best-fit line, not from two arbitrary data points.