Errors

Most experimental measurements are susceptible to errors, whether from limitations of the experiment, errors of the operator or fluctuations of the conditions.

Experimental measurements should always be reported with an estimation of the likely errors. Reporting a measurement without an error estimate is useless because no-one will know how reliable the measurement is. In the worst cases, claiming higher precision than is justified is tantamount to scientific fraud.

It is therefore a highly important skill for all quantitative scientists to be able to estimate the errors in a result and to work out how to use and combine errors in calculations.

Errors can either be reported as absolute errors (i.e. in the same units as the measurement) or as relative errors (i.e. as a proportion of the measurement like a percentage or in parts per million), whichever is more convenient or appropriate to the situation.

In each tutorial the level of difficulty of each topic is colour-coded.
This is intended to give you some idea of when it might be appropriate to have a go at it. The colour codings are intended to mean:

Level 0 (green)- this is basic material that you have probably encountered already, although the approach may be slightly different. No prior knowledge is assumed.

Level 1 (gold) - this material has some prerequisites that are covered in the first year mathematics for chemists course. It will be made clear what these prerequisites are; many students will have covered them already as part of Physics or Further Mathematics.

Level 2 (red) - this material is more advanced. It has been provided as background to help you understand courses in the second and third years. You may not be in a position to understand this until you have completed and digested the first year.