Step 4: Procedure – Testing the Hypothesis with an Experiment

In the procedure, the materials that will be used and the steps to be followed while performing the experiment are recorded. Then, the experiment is performed to test the hypothesis. The materials list must be complete and the steps must be clear so that another person can repeat the experiment without having you there for guidance. Procedures are best written as a numbered list.

Step 5: Data Collection – Analyzing Results

As you perform your experiment, you will collect data on the variables being tested. These data will help you determine if your hypothesis is correct or incorrect.

Regardless of the experiment, accurate data collection is necessary to maintain the honesty of the experiment. In science, a measurement is accurate if it correctly reflects the size of the thing being measured. For example, a perfect grade on a test would be 100%. If three students receive a 99%, 100%, and 98%, the results would be considered accurate.

On the other hand, precise means that an experiment is repeatable, reliable, and gets the same measurement each time. This could be exemplified by a student taking three tests and getting a 85% on all three – her results are not accurate (100%), but they are repeatable, getting the same grade each time. Remember, you can never make a perfect measurement. The best you can do is to come as close as possible with the equipment and technology you have access to.

Once you have collected your data in the most accurate and precise way, the next step is to communicate your data. Visual displays are a very effective way to display the data collected. Common ways of doing this are to create a table or a graph.

A table is a well-organized summary of data. Tables should display any information relevant to the hypothesis, and should include a clearly stated title, labeled columns and rows, and measurement units. Table 1 displays data collected to test the hypothesis “If females study before sleeping rather than after sleeping, then they will perform better on their exam the next day.”

Table 1: Grade Outcomes if Student Studied Before or After Sleeping

A graph is a visual representation of the relationship between the independent and dependent variable. Graphs help to identify trends and illustrate findings. Here are some rules to remember when graphing:

Step 6: Conclusion

Scientists draw conclusions by examining the data collected during an experiment. There are two possible outcomes. Either the experiment supported the hypothesis and it can be regarded as true, or the experiment disproved the hypothesis. If the hypothesis is false, scientists may adjust their hypothesis and repeat the experiment. If the hypothesis is shown to be false against, scientists ask “why.”

The results of an experiment are communicated through a lab report. The following table describes the components of a lab report.