Gathering data
Once you have determined what protocols to use for your project, you will need to develop a plan for gathering the data. It might consist of using automated data collection or making your own measurements. Also, it may include finding data taken by others, such as when you compare your observations with those of another GLOBE school.
Automated Data Collection
If you are using an automated data collection device or devices, verify that the data are being recorded properly before your official testing timeframe. You will want to monitor that the data are being collected and recorded throughout your testing timeframe.
Instruments
If you are taking your own measurements, there are additional steps required, but you will gain valuable hands-on experience. The first thing to do will be to obtain the instrument(s) necessary for the measurements in your investigation. You will also need to ensure that you know how to use the instrument(s) properly and to consider their accuracy and precision.
Accuracy, or how close a measurement is to the actual value of what is being measured must be assessed. To do this, a value taken with your instrument will need to be compared to a standard or known value. This is called calibration. For example, a thermometer can be placed in an ice bath to verify that it reads 0°C.
Precision is how close the measurements are to each other. This will be important when taking the measurements in order to provide consistency. Before your testing timeframe begins, you should take multiple measurements to verify that they are close to each other and that you are using the instrument(s) correctly. If multiple students are taking measurements, practice to make sure their results are close to each other before starting project measurements. Finally, many GLOBE protocols request three trials each time measurements are taken for the project. If one measurement is considerably different from the others consider whether an error may have occurred. If, after careful consideration, it is determined that the measurement is an outlier and was made in error, it can be eliminated, and another measurement can be taken.
Measurement Frequency
Determine how often you need to take measurements. Depending on the protocol(s) being used and the goal of the project, the frequency of data collection may vary. For example, measurements may need to be taken daily, multiple times per day, weekly, etc.
Taking and Recording Measurements
Set up a lab notebook or binder. This might include the GLOBE data sheets for your specific protocol(s). Or, it can include tables to record the data. Make sure to leave room for comments and additional observations which can often be very useful information. It is important to write down the measurements so they are available in the event of equipment errors or failure. It is also important to keep a log of when measurements are taken and when they are NOT taken. If a scheduled measurement can’t be taken, log the reason why. This will help you analyze data later. It is vital to take care in gathering data. Follow the protocol carefully. If it is appropriate, do three trials each time a measurement is made. Then, check for precision.
Entering Data into the GLOBE Database
At present to enter data into the GLOBE database, you must have your site defined unless you are using the GLOBEObserver app. This will be part of the protocol, but will only need to be completed one time. Once the site is defined, there are several options for entering the data into the GLOBE database. It can be done through the GLOBE app, GLOBEObserver or desktop data entry. In addition, it can be entered by a teacher, one student or multiple students. In most cases, it is best to enter the data as soon as possible so that minor errors can be quickly addressed and corrected.
Presentation of Data
When you are ready to present the data, it can be retrieved from the GLOBE database. If you use the Advanced Data Access Tool (ADAT), you can enter the parameters and download data in a CSV file.
Now let’s use an example. Imagine your school has been measuring the max and min temperature for a while, and now you are collecting the data for this semester. You came up with a really exciting research question and figured out what you need.
Let’s say your research question is something like “during which season is there the largest difference between the maximum and minimum air temperature?”
What do you do next?
You can continue to collect temperature observations while you start thinking about your data.
Don’t worry about how you will figure out the answer, let’s just start with making a plot and spend some time looking at the data and thinking!
At the GLOBE data visualization webpage, select the protocol then click on your school on the map. You should see something like this below:
Hit the ‘Plot All’ button if you want to see both max temperature and min temperature on the same plot like this:
Now stare at the graph and Think, think, think….
Can you tell just by looking at this plot which season has the largest difference between maximum and minimum temperature? Could there be any other data that may help you solve the problem?
The plot looks fine, but if you want numbers to answer your research question, you are going to have to do some math!! You will need to find the difference between the max and min temperature for each day you have data on the plot.
Oh boy….how do you do that?
Let’s get the data!
Go back to the GLOBE data tab, and this time instead of selecting ‘visualize data’, select ‘retrieve data’ then hit the big blue button that says ‘enter the data access tool’. You can then select the protocol and your school to get the data. You should see something this:
Now you have data that you can work with and make your own plots.
Congratulations! - You are now in the process of analyzing your data!
