METHODOLOGICAL NOTE

As if the problem of overlapping exchanges or the addition of new exchanges wasn't enough, telephone companies have found yet another way to derive market researchers crazy - the area code split.

When the volume of telephone numbers in an existing area code gets too large, the phone company splits the existing area code, assigning some of its exchanges and households to a brand new area code. It's not that the area code is actually splitting, it's that all the exchanges in the area code are being divided, geographically, into two groups: those remaining in the original area code and those assigned to a new area code.

In reality, area code splits are due more to an overload than to a complete saturation. Areas that have experienced recent area code splits include Chicago (708 & 630), Minneapolis (612 & 320) and Fort Lauderdale (305 & 954).

The biggest complication is the "grace period" allowed for people to become familiar with the new area code boundaries. This grace period is broken into four distinct time periods which we refer to as phases. The telephone companies have made our lives even more difficult by insuring that there is no consistency in the length of each phase or which ofthe phases may be eliminated completely. The phases are organized as follows:

Phase I: The Announcement. A change has been announced to the public, but callers must continue to use the old area code. This alerts those affected ofthe pending split.

Phase III: The Operator Intercept. During this phase, if the caller uses the old area code, the call will be interrupted by an "operator intercept recording" that says the number must be re-dialed usingthe new area code. This causes no sampling problems, assuming the interviewers recognize the intercept for what it is and redial the number using the new area code. If, however, the interviewer does not recognize the intercept message and proceeds to quickly disposition the sample as a "disconnect", well, the repercussions are fairly obvious. Either way, it will add to data collection costs. (A special caution for those using automated dialing systems: these systems will also consider these intercepts to be "non-working.")

Phase IV: It's History. At this point, the only message the caller will get (if the old area code is used) says that the number you have dialed is not in service - usually, "you have reached a nonworking number."

This creates a problem because there will be no indication whatsoever that the telephone number dialed has been assigned to a new area code -the message is indistinguishable from the one used for regular disconnected numbers. If the sample has reached this stage without being corrected, you've not only increased the data collection costs but you have also eliminated households in the new area code.

By now you may be asking yourself "what does this have to do with me?" Well, the problem is that you must make sure that corrections have been made to both your RDD and listed samples. Failure to do this before Phase III will increase your data collection costs and ultimately bias both your sample and your survey results.

The next question is "when should these changes be made?" Our suggestion is to wait until it's as close to the end of Phase II as possible in order to avoid situations such as the one now known as "The Second Burning of Atlanta." After announcing which areas would be covered by the new Georgia area code, a number of lawsuits were filed to block the proposed change. The whole process was officially delayed during Phase II, and then, as part of an "out of court" settlement, a number of concessions were made regarding the new area code boundaries, and Phase III was begun with just a few days notice. (Our condolences to those who got a jump on the process and made their database changes based on the original information).

GENESYS sends out full or interim updates to insure that GENESYS in-house users have the most accurate and up-to-date area code assignments.Our users always have the new area code splits in their database prior to the end of Phase II.

If area code definitions are not current, you could run into a problem similar to that experienced by one of our clients. Unbeknownst to anyone, the sample they received from their client had not been updated to account for a critical area code split. There were tremendous initial data collection problems since the area code split represented a significant part of the sampled area. While we did correct the problem for them, we were somewhat surprised to find that the sample came from one of the large telephone companies. Then again, maybe we shouldn't have been surprised.

Area Code Overlays - an Alternative to the Area Code Split.

The area code splitis the phone company's traditional method of dealing with number shortages. Splits do provide additional phone numbers, but they also create difficulties for telephone users in general, not just survey researchers. For example, businesses in the area assigned to the new area code often need to reprint stationery and repaint trucks to reflect the change. This can represent a significant economic burden. Other difficulties include the loss of market area recognition or status that is part of being located in the existing area code, as well as the need for switch/PBX/cellular reprograming. The telecommunications industry as a whole acknowledges that area code splitting is the relief method most disprutive to the end user.

A new means of area code relief that's "less disruptive" for most users is about to be adopted by the phone companies. Known as an area code overlay, its implementation involves overlaying a new area code on the same geographic area served by the existing area code. In other words, two area codes now serve the same geographic area.

Although it's easier for the typical phone company customer (numbers using the new area code are only assigned to new phone hook-ups, no one is forced to change their number), its use can create a whole new set of headaches for the survey research community.  For example, location will no longer be sufficient to determine the area code, and local calls will require dialing ten or eleven digits.  Additionally, you must be even more careful if your client provides a list without any area codes at all.

GENESYS Sampling Systems maintains a list of all area code splits and overlays, along with their associated effective dates.  Please feel free to direct any concerns or questions regarding this or any other sampling issue to GENESYS Sampling Systens at 800.336.7674.