Understanding Metadata

Dear GLOBE Students--

I hope you are having a chance to look at the data being reported by your school and others in your area.

Scientists try to be thoughtful when looking at data -- both their own and that of their colleagues. One of the first questions they ask is, "Do these data look reasonable?" For GLOBE data, what is reasonable varies from location to location. Snow in warm regions in summer doesn't seem reasonable. That one is easy!

What is reasonable for your site? That depends on what kind of site it is. A pond does not behave in the same way as a stream; a grassland is different from a forest. For this reason, it is important to know some facts about your GLOBE observation sites before deciding what is reasonable. These facts provide useful information about the site characteristics (for instance a north facing hillside) and the conditions under which your measurements were made (for instance a windy day). They are data about data, and scientists call these metadata. The time and location at which you made your measurements and the GLOBE measurement protocols you followed are also examples of metadata.

Now, remember that scientists will be using your data for years to come! You and your classmates will not be available to explain your observations. Metadata is also crucial when scientists years from now try to use your data to understand our environment and explain some phenomenon that they are studying.

Take a look at some GLOBE data and ask yourself the question, "Do these data look reasonable?" What metadata do you need to help you answer this question? If you were a scientist looking at these data years from now, what metadata would you want to have? Can you get these metadata? How?

Look at the GLOBE II Data Entry Sheets for defining your observation sites. To see these sheets, click on the data entry icon, then click on "GLOBE II Data Entry" and then on "Define a Study Site" or ask your teacher for a copy of these sheets from the GLOBE II Teacher's Guide. On these sheets, GLOBE science investigators are asking you for metadata. Are the facts they request the same ones you would recommend? If you want to suggest additional metadata that should go with the data you are collecting at your school, please send me your suggestions, and keep track of your additional metadata in your local record of the GLOBE data collected by your school. Send your suggestions by GLOBEMail or email me at dbutler@globe.gov.

Dixon M. Butler
GLOBE Chief Scientist