In a move designed to make it easier for technology vendors to develop streamlined "plug and play" tools for multiple listing services, the Real Estate Standards Organization (RESO) has adopted a standardized set of data terms for the most common descriptions of property characteristics used by industry players.

Data Dictionary 1.0 contains 503 terms using common definitions for property data based on the Real Estate Transaction Standard (RETS), a real estate data standard implemented by RESO and developed for the purpose of facilitating data sharing within the industry.

The majority of the more than 900 MLSs nationwide, and virtually all that are association-owned, exchange data through RETS feeds, according to RESO. But because many of those MLSs still employ different data definitions, the tools vendors develop for one MLS won’t necessarily work for another.

Regional variation in preferences, technologies and terminology have made efforts to standardize the terms used to describe for-sale homes difficult in the past.

"As the RETS Standard has grown, it has become abundantly clear that a ‘common ground’ for fields and enumerations is needed," RESO said in its introduction to the dictionary.

"Keeping a central requirement to express property and listing concepts in a uniform fashion will mitigate implementation errors, ease field mapping, and foster innovation around a more stable and cost-effective center."

MLS software vendor FBS is already planning to roll out a platform in coming months that will allow software developers to create products for brokers and MLSs using data from more than two dozen MLSs standardized according to the Data Dictionary and offer them in an online app store for real estate software.

One particularly troublesome field to uniformly define has been the number of bathrooms in a home, for example, because it can be represented in text, decimals or fractions, and depends on which bathroom fixtures are present in the room. The Data Dictionary addresses the problem by breaking down the number of bathrooms into separate fields:

  • BathroomsTotal;
  • BathroomsFull;
  • BathroomsHalf;
  • BathroomsThreeQuarter;
  • BathroomsOneQuarter.

The "BathroomsTotal" field is a text field that allows the use of both numbers and letters, either "1.5" or "one full and one half." The remaining fields for bathrooms allow only single numbers and define each type of bathroom.

For example, a three-quarter bath is "a room containing three of the four elements constituting a bath, which are: toilet, sink, bathtub or shower head. A typical three-quarter bath will contain sink, toilet and shower. Some may consider a sink, toilet and tub (without a shower) a three-quarter bath, others consider this to be a full bath."

According to Rob Larson, who spearheaded the Data Dictionary project and is chief information officer of California Regional MLS, the "BathroomsTotal" field is designed to be a sort of "catch-all" legacy field that will likely be updated over time as more and more MLSs adopt the Data Dictionary and understand the use of "quarters" in bathroom configurations.

Eventually, "that text field will become an integer" and "the BathsTotal (will represent) a sum of the rooms that are bathrooms," Larson said. For instance, a home with two full bathrooms and two three-quarter bathrooms will have a BathroomsTotal number of four.

Begun at RESO’s fall conference in September 2011, the dictionary was finalized and subsequently approved by RESO’s board at its spring conference in late April. RESO was previously part of the National Association of Realtors and became an independent nonprofit trade group in November 2011. The trade group currently has 40 members comprised of MLSs, industry technology providers, and real estate associations, including NAR. 

RESO will not make any changes to the Data Dictionary until at least its fall conference this September, Larson said. The work group in charge of the dictionary has established guidelines for suggestions of new fields, which are included in the dictionary document.

While Larson expects some small percentage of additions in September, he anticipates there will be fewer changes in April and, by the end of 2013, a "quite small, manageable number of changes" henceforth representing the "evolution of the industry."

While MLSs may implement the Data Dictionary by incorporating its fields into their RETS feeds, Larson urged MLSs to "go deeper."

"I am literally changing my data structure in my system to more closely match the Data Dictionary. Our recommendation is take the Dictionary to heart," he said.

Travis Wright, executive director of RESO, called for a rapid, industrywide adoption of the Data Dictionary.

"The greater the adoption by the industry, the easier it will be for software developers and vendors to create products that will work seamlessly in all MLS environments," Wright said in a statement.

At RESO’s conference this fall, the trade group expects to adopt a project that will bring together creators of leading real estate APIs (application programming interfaces) to develop a more streamlined way of exchanging data, particularly across mobile devices.

"RESO will unify and modernize the technology responsible for delivering data, completing the final step necessary for plug and play automation," the group said.

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