A high school biology teacher asks her students to collect daily rainfall amounts at each of their homes during the summer. The results will be collected and used to establish a baseline for local weather patterns. What one aspect of the data gathering should the teacher emphasize most to the class?

Establishing a standard method for delivering the results to the teacher

Creating an online chat group for asking questions and posting solutions

Offering a wide variety of rain gauges for everyone to choose from

Using a standard unit of measure for the duration of the study

When collecting data in an experiment, the unit of measure needs to be set to ensure that all data collected will be precise. If everyone used a different unit of measure, the Teacher would need to convert the values into a single unit which is not always as accurate nor precise. It needs to be the same unit because that is the only way you can compare numerical data.

As for the other answers:

Establishing a standard method for delivering the results to the teacher has nothing to do with data gathering, this also includes the second option. As for the third option, it is BEST to use the same rain gauges to get accurate results. It limits any other intervening variables that may change the result of another.