Writing a Lab Report
Introduction—continued
Step 2. Experiment
Accurate observations must be made during an experiment. Observing requires the use of all the senses—sight, smell, hearing, taste, and touch—to measure changes such as plant height, leaf colour, leaf size, number of leaves, etc. You should record in detail everything you observe, including changes you didn’t expect or that don’t seem to be part of the experiment, such as fungus growing on the leaves. Many scientific discoveries (e.g., penicillin) are the result of accidents in the laboratory.
The information you record while making observations is called data. Data can be reported in written form, such as a paragraph, or in tables and graphs.
Two important things you should remember about experiments:
- You must have a control
- The procedures must be repeatable
A control is something to which the experimental data can be compared. For example, if you experiment with growing pea plants in two different fertilizers, then you would compare those plants to another group of plants grown under the same conditions but with no fertilizer. The plants grown without fertilizer are referred to as the control. A valid experiment must have a control.
