Resources

Recording, Manipulating and Reporting Data

Trainee analysts often make mistakes in the recording, manipulating and reporting of data. The supervisor needs to check that the trainee knows how to correctly handle data.

Keeping a notebook is essential for successful experimental work. Notes should provide an accurate record of the events that have happened throughout the experiments and can be further used as a basis to write detailed reports. Enough information should be recorded so that a colleague can repeat the experiments using the notes. In special circumstances, some laboratories (such as those in the field of forensic science and/or drug analysis) may have certain procedures for recording information in notebooks.

Writing short and detailed reports will be a task that is necessary irrespective of whether the analyst is in education or working within industry. They are essential because they can be used to inform others of the outcome of the analyst's work and may provide the basis for future work.

The following sections provide key information on these important topics.

Handling data

Keeping a laboratory notebook

Writing a report

Handling data

When handling data, the analyst should:

• record data correctly and legibly, e.g. when recording an instrument reading in a work book;
• be able to copy correctly a set of numbers, e.g. 20 results from one place to another without losing or transposing results;
• record numbers using the correct units, e.g. µg, mg, g, etc. for weighing data;
• understand and be able to apply the principle of significant figures;
• make sure that the data goes in the correct place when using a data capture system, e.g. when handling several samples, make sure data are assigned to the appropriate sample number;
• ensure the right data are recorded correctly when using a laboratory information system;
• know how to enter data into a spreadsheet and obtain a calculated result(s) and a hard copy;
• use common sense when evaluating results, e.g. the mean of 11.12, 11.38 and 11.43 will be between 11.1 and 11.5;
• be able to perform simple calculations correctly with a calculator;
• record calculations in a work book so that they can be followed by another analyst;
• be able to set up a control chart with appropriate action and warning limits;
• know how to interpret results on a control chart;
• know how to plot a calibration curve, e.g. using a computer software package to calculate the slope and intercept;
• understand the output from statistical packages, e.g. correlation coefficient, residuals, t and F tests etc;
• use specialist functions correctly, e.g. know that it is inappropriate to force a calibration curve through zero, unless there is evidence to confirm that the intercept is not significantly different from zero;
• use the ‘output data’ from statistical software correctly, e.g. to determine the linear range and limit of quantitation for a calibration curve;
• know how to use the calibration curve to calculate, e.g. the concentration of the analyte in a test sample;
• know how to use regression analysis to determine the form of the relationship between two parameters, e.g. linear, quadratic.

Keeping a laboratory notebook

When keeping a laboratory notebook, the analyst should:

• write legibly;
• record the date and title for individual experiments;
• record the list of objectives of the experiment;
• record the reaction schemes if necessary;
• where appropriate, make notes of potential hazards related to the experiment;
• refer to the method or standard operating procedure used and/or write a brief description of the method used;
• record relevant equipment details, e.g. serial numbers;
• record results and observations at the time they are obtained/made;
• include graphs, spectra and appropriate spreadsheet data;
• record conclusions and/or outcomes;
• make corrections by drawing a line and initialling the change rather than using correcting fluid;
• note possible changes required if work is to be repeated.

Writing a report

When writing a report, an analyst should:

• write the report in a clear and concise style;
• use language that is appropriate to the target audience;
• present the information in a format that can be readily comprehended, e.g. using tables and graphs;
• write a report of an appropriate length and in the required style;
• include sufficient data and calculation detail to satisfy the reader;
• produce a report that contains an informative introduction and a summary;
• make clear any conclusions and/or outcomes reached;
• explain interpretations where appropriate, e.g. comparing the result of an analysis against a regulatory limit;
• differentiate clearly between opinions and factual information contained in the report;
• make comments on future work, if appropriate;
• file the report in a safe place where it can be found at a later date.