Process for Defining Standard Fields for MLSs

Oct 5, 2009 Michael Wurzer

In my last post, I mentioned that RETS data standards may get a boost from the COVE Group of MLSs starting to work together on further defining standard field names for their MLSs. Standard names have existed for a long time in RETS but they are rarely well populated. This new effort is to reinvigorate standard names and try to figure out how they can be changed so they are actually put into use.

Because there are other regional data standardization efforts across the country, I suggested in my last post that sharing the process for this work with the broader community would be helpful so that the work can be coordinated with work other groups are doing. One of the most basic first steps is defining a format for publishing the agreed upon fields. Spreadsheets tend to be the easiest way for the broadest group of people to access the results, and so they are most commonly used in data standardization efforts.

One of the challenges with spreadsheets, though, is that they are two dimensional and the listing data often is nested, especially when it comes to fields with a list of values. How do you best show the field name and the list of values? One approach is to combine them into one sheet and another is to include the list of values on a separate sheet as shown in the example below (though I couldn’t figure out how to link the two sheets together in Google documents).

Another question is whether to include the data type in this initial effort. In the past, defining data type has created a lot of consternation where, for example, some MLSs use a list of values for number of bedrooms while most others use a numeric value. If this effort is to have meaning and usefulness long term, I think we have to define data types as well as names. Lastly, even though RETS schema doesn’t define fields by property type, I suggest the spreadsheet contain a property type column to define those fields particular to certain property types.

I think using Google Documents or some other web based spreadsheet would make sharing and publishing the information on sites like much easier for everyone. Sharing is critical for getting input and feedback, and building consensus around the results. For example, if you think of a better idea for how to format the spreadsheet, you actually can edit the spreadsheet above and the changes will be saved. That’s pretty cool. Google Spreadsheets also can grant only specific people permission for editing.

So, does this approach work for groups to create and share standard fields in an effort to come up with widely adopted standard fields? One of the core objectives is to get as many fields commonly searchable across all MLSs as possible. Is that 50 fields? 100? More? If there aren’t many current fields, will MLSs be willing to change their current fields to adopt to new standards? Lots of questions here but I know there are many MLSs grappling with these exact problems right now and so this is the time to put keyboard to spreadsheet and define as many standard fields as possible.