Maria and her brother like to go fishing at the lake on Saturdays. They wondered if fish were more likely to bite at one time of day than another. They decided to try an experiment over the next two Saturdays:

On the first Saturday, it was hot and sunny, and they went fishing in the morning. Maria and her brother caught five fish. On the second Saturday, it was overcast and cool, and they went fishing in the afternoon. They only caught three fish this time.

Should they conclude that fish bite better in the morning? Select the best answer and explanation below.

No. They will need to repeat their experiment several times, since the weather and times were different both days.

Explanation:

When a scientific experiment is conducted, one independent variable shall be changed in each experiment at a time so that the results of the experiment are authentic and we can easily determine which independent variable caused a change in the dependent variable.

If more than one independent variable is changed in the same experiment, then it will be difficult to interpret that which variable caused the change.

Similarly, Maria and her brother need to repeat their experiment several times with just changing one variable at a time.