Lab Report Grading Guidelines

These Grading Guidelines are intended to help supervisors assign grades appropriately for lab work and lab reports, and to help students understand what is required to produce high quality work.

Practical Lab Work

4 Marks

All experimental lab work should be completed satisfactorily. Students should lose marks if the work is not completed, or if it is done carelessly or less accurately than the equipment allows.

Title and Goal / Hypothesis

1 Mark

The lab report should have the correct title, and should begin with a clear statement of the goal of the lab or the hypothesis that the experiment is intended to test.

Whether a goal or a hypothesis is appropriate depends on the nature and aim(s) of the experiment itself. If the experiment simply aims to make an observation, then a goal is likely to be most natural (e.g. “To observe the impact of temperature on diffusion rate”). If the experiment is intended to test whether or not a certain claim is true, then a hypothesis is more appropriate (e.g. “The amount of sodium chloride that will dissolve in a given volume of water will vary with temperature”).

In many cases, either a goal or a hypothesis is fine, since a hypothesis can often be re-stated as a goal or vice versa. For example, the hypothesis “The amount of sodium chloride that will dissolve in a given volume of water will vary with temperature” can be re-stated as the goal “To test whether the amount of sodium chloride that will dissolve in a given volume of water will vary with temperature.”

Method

1 Mark

The lab report should describe what was done in enough detail to allow another student to repeat the work by following the instructions.

Note that minor details (e.g. where equipment is stored) or irrelevant matters (e.g. the color of a plastic container) do not need to be included, but there is enough detail for another student to repeat the work. The method should usually be written in the passive voice (e.g. “Water was poured” rather than “I poured water”).

Diagram

1 Mark

A simple labelled diagram should be drawn in pencil, using a ruler to draw straight lines. As with the method (above), the goal is to give enough detail for another student to set up the experiment in the same way. Minor details and irrelevant matters should not be included in the diagram.

Results and Analysis

2 Marks

The results of the experiment should be described in an appropriate way, and any necessary mathematical analysis should be done. The exactly results obtained may of course differ slightly from those found in the sample reports. However, if the experiments are done correctly, the results should be similar, and the overall trends should be the same.

The best way to describe the results will depend on the nature of the results themselves. Sometimes, simple statements are fine (e.g. “The reactants fizzed and bubbled, and the balloon inflated rapidly”). Sometimes numerical results should be given, remembering to state what the numbers refer to, and to include the units (e.g. “Mass of salt = 23 g” is good; “23 is unacceptable). If there are lots of results, a table may be used to display the results more clearly. In this case, the headings should state what the numbers refer to, and the units they are measured in.

In some cases, it may be helpful to display the results in the form of a sketch or photo (labelled), or a graph. If a graph is used, the points should be marked with neat crosses, the axes should be labelled, and the units clearly given.

In some cases, it is necessary to carry out some simple calculations (analysis) in order to obtain the results. These calculations should be laid out neatly, and the results clearly identified, with units given.

Conclusion

1 Mark

Finally, the conclusion of the lab should be stated. This should relate back to the goal (stating whether or not the goal has been accomplished) or the hypothesis (stating whether or not the hypothesis has been confirmed).