The term experiment is defined as a systematic procedure carried out under controlled conditions to discover an unknown effect, or to test and establish a hypothesis, or to illustrate a known effect.
There are seven parts of an experiment:
1. Question/Title – It is a brief query that describes the main purpose of the experiment.
2. Hypothesis –Hypothesis is a prediction about what might happen in an experiment. If the proposed hypothesis is found to be correct, even after repeated experiments, it turns out to be a theory.
3. Materials- The list of equipment-Glassware, Instruments, Chemicals, and other things required to perform the experiment.
4. Procedure/ Experiment –The specific steps followed during the experiment to find out if the hypothesis is correct. The experiments that are successful require numerous trials and errors for standardization of the steps, which can hence forth be performed by anyone.
5. Observation – It is a record of all the changes that took place during the experiment. Observation is recorded and can be systematically represented through charts, graphs and pictures.
6. Results – From the observations during the experiment, a definite outcome of the experiment is reached which is the result. It validates, nullifies or modifies the hypothesis that was proposed at the time of designing the experiment.
7. Discussion/Conclusion – It is the final statement of the experiment, which states if the hypothesis is true or false, and whether or not we accept it or reject it. A conclusion should answer the question with which we started the experiment.
What are variables in experiments?
Scientists use experiments to search for ‘cause’ and ‘effect’ relationships in nature. In other words, we design an experiment to study if changes in one factor can lead to changes in other factors in a predictable way. These changing quantities are called variables. Variables can "vary" - for example, be high or low etc. An experiment usually has three kinds of variables: independent, dependent, and controlled. An independent variable is the one that is changed by the scientist. A good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens to the dependent variable to see how it responds to the changes made to the independent variable. The new value of the dependent variable depends on the value of the independent variable. The dependent variable is the results of what happens during the experiment.
For more information regarding the parts of an experiment see the presentation 'Design Your Experiment.ppt’
For more information on cellular respiration please see ‘cellular respiration teacher’s resource.pdf’