Beta Labs - Yellowpages.com

Local Search, Data Accuracy and the Elusive Canonical Phone Number

An Interview with Neil Symes - Director of Data Management

ca•non•i•cal (kə-nŏn’ĭ-kəl)
1. Of, relating to, or required by canon law.
2. Of or appearing in the biblical canon.
3. Conforming to orthodox or well-established rules or patterns, as of procedure.
source:
www.thefreedictionary.com

One of our jobs as a local search engine is to provide accurate and up-to-date information – including business telephone numbers. This sounds like a simple, straight forward proposition, but it is not. In fact, this is extremely difficult due to the complicated relationship between businesses and their telephone numbers. Our Director of Data Management, Neil Symes, spends a great deal of effort pursuing the holy grail of the canonical phone number.

Q: Can you give me a brief description of what we call a “Canonical” phone number?
A: Well, in a nutshell, it’s the actual phone number for that business. When we list a business, we want the phone number to be the ACTUAL phone number the person will need to call to reach the business, not their fax number or back office number.

Q: Why is this data difficult to obtain?
A: There are many, many reasons this is problematic. There are toll free numbers, call tracking numbers, fax numbers, even businesses with multiple numbers in multiple area codes. In addition, a business may have a primary line with hundreds of extensions. These extensions may have direct dial capability as well. So “what is the phone number” for a business, person, or department at a business is extremely complex. The control of phone numbers is split between the traditional Telcos, wireless providers and VOIP so obtaining a standard across the industry for reporting the canonical phone number could be a challenge. With canonical web addresses, the control and benefit are both in control of the website owner; with telephone numbers, the control is within the various telephone service providers and advertising agencies, with the benefits going to the search engines. Even within the Telcos they have difficulty tracking this information. For example, phone numbers are recycled / reassigned quickly when a business closes its doors. In some drastic circumstances this can occur in a 30 day period.

Q: What other challenges are there?
A: Mobile numbers have added an entirely new dimension to the data accuracy question, as they do not point to a location, but to a person. There are also situations where a national business will want different phone numbers displayed, such as a national number on a search results page, but a local number on a MIP (More Information Page).

Q: Is this a problem for all search engines?
A: This is mainly a problem for Local Search web sites. A typical search engine brings back a list of relevant websites, but in local search we bring back a list of relevant businesses and their telephone number. In this context it’s important to note that not all businesses have websites, but most do have a telephone number. Determining the right telephone number for a business is crucial for local search. This isn’t an easy problem to solve, but we apply innovative technology and our deep understanding of businesses and their use of telephone numbers to develop solutions. Are we perfect? No, but the reality is – no one has perfectly solved this problem. We are always looking for better solutions and would love to hear from other “students of the canonical phone number” how to be even better.