PREPROGRAMMED OVER-THE-AIR MARKETING RESEARCH SYSTEM

BACKGROUND OF THE INVENTION

A. Field of the Invention The device of the present invention gener¬ ally relates to systems and methods for performing marketing research in a targeted test area and, more particularly, to a system and method for performing over-the-air marketing research in households having television sets in the targeted test area.

B. Description of the Prior Art

The monitoring of the activity of televi¬ sion sets in cooperating households for various pur¬ poses is old and well known. Typically, cooperating households having television sets are furnished with a diary to be filled out by those people who watch television in the households. This method has several limitations including lack of attention and human error in making diary entries. Other systems have been designed to automatically monitor the acti¬ vity of television receivers in cooperating house¬ holds, that is, the "on-off" condition of tne televi¬ sion receivers and the identity of the channels being viewed, to store such information accumulated during an entire broadcast day in a small computer installed in each cooperating household and properly to organ¬ ize or format such information for transmission at the end of a broadcast day over telephone lines to a central computer. Examples of such systems are set forth in United States Letters Patents Nos. 3,651,471; 3,742,462; 3,742,463; 3,772,649; 3,973,206; 4,025,851; and 4,048,562. Such systems, however, lack flexibility in that they do not provide for the testing of viewer response to substitute pro¬ gramming, such as substitute commercials. In addi¬ tion, such systems may only monitor television acti- vity on a periodic basis, that is, time dependent sampling, rather than on a real time basis, that is, continuous monitoring.

United States Letters Patent No. 3,639,686 discloses an over-the-air marketing research system in which a substitute television signal is broadcast throughout a broadcast area over a VHF or UHF channel not being utilized by television broadcast stations operating in the area. In one embodiment, a control signal is broadcast that identifies a preselected class (occupation) of viewers to be reached by the substitute television signal. Those households hav¬ ing television receivers equipped to receive the sub¬ stitute television signal and also having a household identification corresponding to the preselected class of viewers are capable of receiving the substitute television signal if the television receivers in the households are tuned to the designated channel. This system is limited in that the households in each class of viewers are fixed upon the installation of receiving equipment in each household and cannot thereafter be altered or subdivided without the in¬ stallation of new equipment. In addition, convention transmitters broadcasting the substitute television signal over a standard VHF or UHF channel with normal signal strength would result in an inordinately ex¬ pensive system. With the development of cable television networks, marketing research has been performed through systems that are capable of delivering alternate programming material to cooperating households via coaxial cables. An early proposed system is dis¬ closed in United States Letters Patent No. 3,366,731 and constitutes a split cable system having two coax¬ ial cables emanating from a single transmission source that service either different portions of the same test area or alternate households in a test area. Again while substitute programming can be transmitted over one or the other of the cables, this system lacks flexibility in that it is the initial connection of a particular distribution cable to a particular household that determines the test group. The groups may not be changed unless the connection of the distribution cable to a particular household is changed. In addition, this system does not enable the subdivision for marketing research purposes of households connected to a particular distribution cable.

United States Letters Patents Nos.

4,331,973 and 4,331,974 disclose a cable television network for accomplishing marketing research that is capable of providing substitute television signals, for example, substitute commercials, over one or more unused cable channels. The disclosed system switches substitute programming for the regularly scheduled or standard programming in cooperating households by a command over the cable network. The system also is capable of recording at the transmitting end the channel being watched by the cooperating households.

Such recorded data subsequently may be correlated with the purchasing habits of members of the cooper- ating households.

While such a system constitutes an improve¬ ment over many other conventional marketing research methods, the system is limited by the fact that it utilizes a cable network for performing the marketing research and by its inability to preprogram an entire substitute programming schedule for an entire broad- casting day and by its lack of local or household storage for recording at each cooperating household the activity of that household's television receiver during an entire broadcasting day. In addition, since the majority of the households in the United States having television receivers are not serviced by cable, truly demographic marketing research test results are not practically obtainable. For example, only the relatively affluent in a particular test area served by cable television can afford the onth- ly cable television subscription fee. Thus, only the relatively affluent could participate in such a mar¬ keting research system utilizing cable television. A need therefore exists for a marketing research system capable of fairly and accurately measuring the re- sponses of consumers to new products, ideas and tele¬ vision program content without regard to the consum¬ er's economic status or the electronic progress in a particular community.

SUMMARY OF THE INVENTION An object of the present invention is to provide a new and improved marketing research system and method.

Another object of the present invention is to provide a new and improved method and system for conducting marketing research in cooperating house¬ holds having television receivers.

Another object of the present invention is to provide a new and improved method and system for conducting marketing research through television pro- gramming directed at cooperating households in which substitute television programming can be transmitted over-the-air and controllably switched into televi¬ sion sets in any preselected cooperating households.

Briefly, the present invention constitutes a new and improved, preprogrammed over-the-air mar- keting research system for conducting marketing re¬ search tests in a given test area through cooperating households having television receivers. Those house¬ holds in a given test area that have agreed to parti¬ cipate in the marketing research tests are equipped with special receiving apparatus that enables the households to receive and view substitute television programming. The system utilizes a local or test area command and control computer; a conventional, normal television signal transmitter for transmitting regularly scheduled television signals over-the-air to non-cable households or a cable distribution net¬ work for providing cable households with regularly scheduled television signals; and a lower power, high frequency ground based microwave transmitter or, al- ternatively, a transponder mounted in an earth-orbit¬ ing satellite for broadcasting a special television signal over-the-air (as opposed to delivery by a cable network) . The special television signal in¬ cludes substitute television programming, for example, a substitute test commercial, and substitute programming control signals and other information transmitted in the form of digital data. The system also may utilize automatic purchasing response ap¬ paratus placed in cooperating retail stores in the test area for automatically recording the purchases of the cooperating households and for relaying that information to the local or test area command and control computer for subsequent evaluation by market researchers. Each cooperating household is equipped with household signal receiving apparatus that includes an antenna and a combined tuner/converter for delivering a normal over-the-air television signal to a non- cable household or a cable television signal distri¬ bution cable and a tuner/converter for delivering a normal cable television signal to a cable household. Each cooperating household is additionally equipped with a high frequency, high gain microwave antenna for receiving the special_. television signal, a down converter for converting that special television sig¬ nal to an unused channel and a household television control unit. The control unit includes a decoder for separating the audio and video program informa¬ tion portions of the substitute programming signal from the substitute^' programming control signals and associated digital data. The audio and video program information portions are directed to a three-way radio frequency switch; and the substitute program¬ ming control signals as well as the associated data are directed at high speed, for example, 9600 baud, to a household control computer. The household computer receives and stores a substitute programming schedule from the test area command and control computer for an entire broadcast day or a longer or shorter period of time, including, if desired, the approximate time of each substitute programming event. The household computer is also responsible for continuously monitoring and recording the "on-off condition of the television receiver and the identification of the channel being watched. In addition, the household computer controls the condi- tion of the three-way switch, thereby enabling the viewing members of a particular cooperating household to view the normal television signal or the substi¬ tute programming or text and/or music either pre¬ viously stored in the household computer memory unit or decoded from the digital data portion of the special television signal and displayed in real time. In this manner, a new and improved, highly flexible. over-the-air television marketing research system is provided that is capable of effectively and effi¬ ciently measuring the responses of . consumers in a test area to new products, ideas and television pro- gram content without regard to the consumers' econom¬ ic status or the electronic progress in the test area.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects and advantages and novel features of the present invention will be¬ come apparent from the following detailed description of the preferred embodiment of the present invention illustrated in the accompanying drawing wherein:

FIG. 1 is a schematic illustration of a preprogrammed over-the-air marketing research system constructed in accordance with the principles of the present invention;

FIG. 2 is a schematic diagram of a local area command and control computer for use in co junc- tion with the system of FIG. 1;

FIG. 3 is a schematic diagram of television signal receiving apparatus at each cooperating house¬ hold for use in the system of FIG. 1;

FIG. 4 is a more detailed schematic diagram of the television signal receiving apparatus of FIG. 3; and

FIG. 5 is a schematic diagram of an auto¬ matic household purchasing response apparatus for use with the system of FIG. 1. Referring initially to FIG. 1 of the drawing, there is illustrated a new and improved pre¬ programmed over-the-air marketing research method and system 10 constructed in accordance with the prin¬ ciples of the present invention. The system 10 is used in any given test area where individual house¬ holds have been screened to build a test group that, demographically, is representative of the general population. Once chosen, those households that agree to participate are equipped with special receiving apparatus that enables the households to receive and view substitute television programming. The system 10 utilizes a local or test area command and control computer 12 (FIG. 2) and a conventional, high power, normal television signal transmitter 14 for transmit¬ ting a normal or regularly scheduled television sig¬ nal to regular over-the-air or noncable households 16. The system 10 may also be used in conjunction with a cable distribution network 18 that provides cable households 20 with standard television signals over a coaxial cable. Both of the households 16 and 20 are representative of a large number of preselect- ed cooperating households in a particular test area, each of which has been equipped with a high frequen¬ cy, high gain microwave antenna 22 for receiving a special over-the-air television signal. The special television signal includes both substitute program- ming and substitute programming control signals. The special television signal may be broadcast by a low power, high frequency microwave transmitter 24 or, alternately, by -one of the transponders in an earth orbiting satellite 26. Signal receiving apparatus 28 (FIGS. 3 and 4) placed in each cooperating household 16 and 20 control the receipt and utilization of the normal television signal from the transmission tower 14 and the special television signal from the micro¬ wave transmitter 24 or the satellite 26. The system 10 may also utilize automatic household purchasing response apparatus 30 (FIG. 5) placed in each cooper¬ ating retail store in a test area for automatically recording the purchases of each cooperating household 16,20 in the test area. Such information may subse- quently be used by market researchers in evaluating the effectiveness of the normal and substitute tele¬ vision programming. Special Television Signal Transmission In the preferred embodiment of the present invention, the low power microwave transmitter 24 is used to transmit, preferably, continuously, a special television signal having a signal bandwidth of ap¬ proximately six megahertz in the frequency range of from approximately 2.500 to approximately 2.686 giga¬ hertz. This radio frequency (RF) range has been divided in the United States of America by the Federal Communications Commission (FCC) into thirty- one, six megahertz bandwidth channels, known as In¬ structional Television Fixed Service (ITFS) . Prefer¬ ably, the special television signal, which includes both substitute programming signals and digital data in the form of substitute programming control signals and associated data, is broadcast on one of the chan¬ nels in the uppermost portion of the ITFS range. Specifically, one of the three, nonadjacent channels in the H group, collectively referred to as Opera- tional Fixed Service (OFS) and allocated by the FCC on a single channel basis, is used for transmitting the special television signal. If in a particular test area the OFS range is unavailable, then it is preferred to broadcast the special television signal over one of the four nonadjacent channels in the G group of the ITFS range. In any event, by broadcast¬ ing the special television signal in the ITFS range, only a very low amount of broadcast power (under 100 watts) is required. Alternatively, one of the transponders in the satellite 26 may be used to transmit, preferably, continuously, the special television signal. Prefer¬ ably, the special television signal so transmitted would have a bandwidth of approximately six megahertz and be transmitted in the 10.90 to 36.00 gigahertz (K band) frequency range. Advantageously, the satellite 26 would be used to transmit the special television signal in the frequency range of from 15.35 to 17.25 gigahertz (K_u band) . By transmitting in that fre¬ quency range, only a relatively small antenna 22, for example, one less than three feet in diameter, would be required to receive the special television signal. The advantage of using the broadcast satellite 26 is that the special television signal may be received over a much greater area than that capable of being serviced by the microwave transmitter 24. For example, an entire country may be used as a test area by transmitting the special television signal from the satellite 26.

Local Area Command And Control Computer

The local or test area command and control computer 12 (Fig. 2) is but one of a number of re¬ motely located computers 12, each one of which is responsible for controlling the marketing research system 10 in a particular test area, including con¬ trolling the transmission of the special television signal by the transmitter 24 or the » satellite 26. In general, each local computer 12 includes a local area central processing unit (CPU) 32, a local area memory unit 34, preferably consisting of both a random ac¬ cess memory (RAM) and a read only memory (ROM) , and a local area input/output interface (I/O) 36. Elec¬ trically connected to the interface 36 are the trans¬ mitter 24 or the satellite 26, a local area operator control terminal 38 which provides on-site operator control of the local computer 12, one or more auxili- ary memory units 40 and a conventional modem/automatic dialer 42 interconnected with one or more telephones 44 or telephone access lines for com¬ municating both with the signal receiving apparatus 28 at each cooperating household 16,20 and with a central or mainframe system computer (not illustrat¬ ed) . Household Signal Receiving Apparatus The household signal receiving apparatus 28 (FIG. 3) installed in a regular or non-cable house¬ hold 16 includes a normal over-the-air television signal antenna 46 and a conventional, combined tuner/converter 48 that may be tuned by any member of the household 16 to a desired channel to be viewed and that converts the selected channel signal to an unused channel signal, normally channel 3 or 4, for viewing on a television receiver 50. The built-in tuner of the television receiver 50 is fixedly tuned to the selected unused channel (channel 3/4) .

The household signal receiving apparatus 28 associated with each cable household 20 includes a normal television signal cable 52 for delivering a normal multichannel television signal to a conven¬ tional, normal cable television signal tuner/conver¬ ter 54. An individual in the household 20 may select any one of a plurality of television channels deli- vered to the household 20 by the cable 52 by input¬ ting the desired channel into the tuner/converter 54. The tuner/converter 54 converts the selected channel to an unused channel (channel 3/4) for subsequent viewing on the television receiver 50. It should be apparent that a regular or non-cable household 16 would normally not be equipped with the cable 52 or the tuner/converter 54; and, similarly, a cable household 20 would normally not be equipped with the antenna 46 or the tuner/converter 48. Each cooperating household 16,20 in a test area is equipped with the microwave antenna 22 for receiving the special television signal and with a down converter 56 that converts the special televi¬ sion signal to the preselected unused channel (chan- nel 3/4) for delivery directly to a household televi¬ sion control unit 5a. The control unit 58 includes a decoder 60 for separating the audio and video program information portions of the substitute programming signal from the digital data that includes the sub¬ stitute programming control signals and associated data (for example, the current time and the telephone number of the local computer 12 and/or test marketing questions or marketing information or public service messages or other text and/or music) . The audio and video program information portions are directed to a three way (A-B-C) , radio frequency switch 62; and the substitute programming control signals and associated data are directed to a small household control compu¬ ter 64. For illustrative purposes only a lead is shown (FIG. 3) connecting the tuner/converter 48 to the switch 62 and a lead is shown connecting the tuner/converter 54 to the switch 62. It should be understood that in a particular household 16,20 only one such lead would be directed to the switch 62.

The household television control unit 58 and the household computer 64 are shown in greater detail in FIG. 4. The computer 64 includes a central processing unit (CPU) 66; an integral internal clock 68; a memory unit 70 (preferably formed by both a random access memory and a read only memory); an ex¬ pansion bus 72; a video and sound output unit 74 that is capable of delivering text and/or music on the un¬ used channel (channel 3/4) to the switch 62; and an input/output interface 76. The CPU 66, the clock 68 and the memory unit -79 may be physically embodied on the same microprocessor chip, for example, a Zilog Model "z-βO** microprocessor chip.

While it could be transmitted as part of the over-the-air special television signal, normally the computer 64 receives telephonic instructions in advance from the local computer 12 and stores these telephonic instructions that normally include a sub¬ stitute programming schedule for a substantial por¬ tion or all of an entire broadcast day or for a longer period of time, including the approximate time of each substitute programming event. This informa¬ tion is provided to the computer 64 by means of a telephone 7a and an associated modem/automatic dialer 80 located in each household 16,20. The computer 64 is also responsible for monitoring and recording, on a real time basis, (as opposed to sampling at rela¬ tively widely spaced time intervals) the "on-off^w condition of the television receiver 50, which infor- mation is provided by a conventional television re¬ ceiver "on¹* sensor 82. In addition, the computer 64 monitors and records the identification of the channel being watched and controls the condition of the three-way switch 64, thereby enabling the viewing members of the households 16,20 to view the normal television signal from the tuner/converter 48 (or 54) or the substitute programming from the down converter 56 and the decoder 60 or text and/or music from the video and sound output unit 74. Finally, each household television control unit may also include one or more auxiliary devices 86, 88 and 90 for use in conjunction with the compu¬ ter 64, as described in more detail hereinafter. Power to run the control unit 58 is supplied by each household 16,20 as represented by the plug 84. Household Purchasing Response Reporting

The response of cooperating household 16,20 to marketing research tests performed by means of the system 10 may be determined in any one of a number of ways. For example, each cooperating household 16,20 may be supplied with a diary in which each household member records purchases and, preferably, the date, place and cost of the purchases. Such entries are manually made and the diaries may then be later mail- ed to a central collection point for proper format¬ ting and evaluation as part of a particular test. Alternatively, an auxiliary device 86 (FIG. 4) in the form of a Universal Product Code (UPC) scanner may be provided to each cooperating household 16,20. By us¬ ing such a UPC scanner 86, a member of the household can optically scan the UPC code commonly imprinted on retail items for entry in digital form into the household computer 64. After proper formatting, the purchasing information subsequently can be transmit¬ ted to the local computer 12. Preferably, each UPC scanner 86 supplied to the households 16,20 includes either a numerical or an alphanumerical manual entry terminal to permit the entry of retail purchases that lack UPC identification.

As a further alternative, the auxiliary de¬ vice 88 may comprise a standard computer keyboard for entering numeric or alphanumeric representations of retail purchases into the computer 64. Advantageous¬ ly, such a keyboard 88 could also be used to enter into the computer 64 answers to marketing test ques¬ tions received from the local computer 12 and dis- played on the television receiver 50 and directed at one or more members of the household 16,20. The answers would subsequently be transmitted to the local computer 12 for evaluation by market re¬ searchers. The keyboard 88 would also be useful when used in conjunction with the auxiliary device 90 in the form of a small auxiliary computer 90 used for playing television games on the television receiver 50. Specifically, questions preprogrammed in a tele¬ vision game cartridge or received from the local com- puter 12 and displayed on the television receiver 50 in conjunction with the television game being played could be answered on the keyboard 88 and the answers stored, formatted and subsequently transmitted by the computer 64 to the local computer 12 for subsequent analysis by market researchers.

As a further alternative, the retail pur¬ chasing responses of the members of the households 16,20 to marketing tests conducted through the system 10 may be automatically recorded by the automatic household purchasing response apparatus 30 (FIG. 5) . Specifically, each cooperating retail store in a test area would utilize equipment corresponding to the apparatus 30 to record the retail purchases of mem¬ bers of the households 16,20. Whenever a member of the household 16,20 makes a retail purchase, that purchase would be automatically recorded at the check-out counter of the cooperating retail store. Specifically, one of a plurality of Universal Product Code (UPC) scanners 92 would be used by a clerk in the retail store to scan and record each purchase made by a member of the household 16,20 in a conven- tional manner. In addition, the clerk would request or the purchaser would volunteer an identification card containing an optically or magnetically readable code identifying the purchaser in order to associate the purchases with a particular household 16,20. Al- ternatively, the checker may enter a numeric or al¬ phanumeric identification code for the purchaser into the UPC scanner terminal, thereby providing the re¬ quired identification.

A store computer 94, which typically in- eludes a central processing unit (CPU) y6 and a mem¬ ory unit 98 and input/output apparatus 100, receives the purchasing information from the UPC scanner 92, formats and stores the information and, subsequently, in response to an inquiry from the local computer 12, transmits the purchasing information by means of a combined modem and automatic dialer 102 and a tele¬ phone or telephone line 104 to the computer 12 for subsequent analysis by market researchers. The in¬ formation transmitted typically would include at least an identification of the household 16,20, an identification of the purchases made by that house¬ hold 16,20, and the identification of the store transmitting the data. The data may also include the price of each product purchased, the date of the pur¬ chase and the time of the purchase. Each store typi¬ cally is also provided with a terminal 104 for main- taining control of the store computer 94.

Marketing Research System Operation In any given test area, for example, a city capable of being serviced by the microwave transmit¬ ter 24 or an entire country capable of being serviced by the satellite 26, households that agree to be test panelists, of which the households 16,20 are repre¬ sentative, have their control units 58 placed under the control of the local test area command and con¬ trol computer 12. The computer 12 and the household computers 64 of the household television control units 58 communicate over telephone lines, prefer¬ ably, the home telephones 78 of the households 16,20. The computers 64 initiate telephonic communication with the computer 12 through the modem/automatic dialers 80 and transmit data at a standard rate of approximately 300 baud.

The computer 12 receives a substitute pro¬ gramming cut-in master schedule for use in indivi¬ dually programming the household television control units 58 of the households 16,20 from the central computer via the telephone 44 or programmed magnetic tapes. The computer 12 establishes a marketing test matrix that identifies which ones of the cooperating households 16,20 will be members of various test panels for substitute programming test events sched¬ uled to occur during the next broadcast period, for example, a twenty-four to seventy-two hour period. As is apparent, each cooperating household 16,20 can be placed in a specific test panel scheduled to par- ticipate in a test event or omitted therefrom for every programming minute of the day. After each com¬ puter 64 transmits its stored data to the computer 12, the computer 12 transmits an individually organ¬ ized substitute programming schedule to the computer 64 which may include the approximate timing of the scheduled test events. Alternatively, this informa- tion may be transmitted individually to each house¬ hold computer 64 in the digital data portion of the special television signal. Basically, this informa¬ tion establishes a truth table in the memory unit 70 of the computer 64 which, when satisfied and upon the receipt of a synchronization signal, results in the computer 64 changing the switched state of the A-B-C switch 62, and thus the signal delivered to the tele¬ vision receiver 50, from Channel A, the normal tele¬ vision signal, to either Channel B, the special tele- vision signal containing substitute programming, or to Channel C, the preprogrammed text and/or music from the memory unit 70 and the video and sound out¬ put unit 74 or real time text and/or music then being transmitted in the digital data portion of the special television signal and delivered to the switch 62 through the decoder 60 and the video and sound output unit 74. When the test event has been comp¬ leted, the computer 64, assuming no other test event has been programmed to immediately follow, changes the switched state of the switch 62 to Channel A to resume the delivery of the normal television signal to the television receiver 50. If, however, the television receiver 50 had not been tuned to the channel for which the substitution was to occur, the switch 62 would not have been activated by the com¬ puter 64; and the substitution would not have occur¬ red.

The computer 12 also controls the special television signal broadcast by the microwave trans- mitter 24 or by the satellite 26. More specifically, the computer 12 indicates to an on-site operator ex¬ actly when to initiate a broadcast of the special television signal and also synchronizes the substi¬ tute programming, for example, a substitute test com¬ mercial, with the regular television signal.

After each broadcast period (twenty-four hours or longer) , each household computer 64 is pre¬ programmed to call its local computer 12 via the telephone 7a and the modem/automatic dialer 80 to transmit the data stored and properly formatted by the computer 64. Basically, the data transmitted includes a complete real time log of the activity of the television receiver 50 and also marketing research test data inputted into the computer 64 through one or more of the auxiliary devices 86, 88 and 90. The household computers 64 are preprogrammed to call the computer 12 in staggered groups during a time window assigned to each computer 64 during its initial power-up call to the computer 12. If more computers 64 attempt simultaneously to contact the computer 12 than the maximum telephone line alloca- tion of the computer 12, those computers 64 receiving a busy signal are programmed to redial the computer 12 after a random time delay. After the time window for all computers 64 in a local test area to report has passed, the data collected by the computer 12 is sorted, properly formatted and prepared for transmis¬ sion to the central or main frame computer. Such data would include an identification of apparently malfunctioning household computers 64 including those that did not report during the reporting time window. In the unlikely event that a particular memory unit 70 of a computer 64 becomes filled to capacity, the computer 64 assumes an idle state until it empties its stored data during the time window assigned for reporting to the computer 12. The special television signal broadcast over-the-air by the microwave transmitter 24 or the satellite 26 includes an audio subcarrier which serves as a digital data channel to transmit informa¬ tion and/or instructions to the household television control units 58. For example, as discussed above, the time of day and the telephone number of the com- puter 12 are continuously broadcast over this data channel to enable a computer 64 after a power failure to immediately contact the computer 12 to obtain instructions including a substitute programming schedule. In addition, when substitute programming is to be aired, it normally would be proceeded both by an identifying label transmitted over this data channel and a substitution synchronization data bit.

In at least the following three instances, the computer 64 is programmed to contact the local computer 12. The first instance involves a daily or other periodic check-in and data reporting call that takes place within the the preassigned reporting time window. This call will always occur, whether or not there is data to be transmitted by a computer 64. During this call, each computer 64 receives from the . computer 12 an individually constructed substitute programming schedule and other information for the next broadcast period. In addition, every time there is a power failure and upon the restoration of power, - the affected computer 64 performs a self-diagnostic routine. Subsequently, upon receipt of the time of day and the telephone number of the local computer 12 that are continually broadcast as part of the special television signal, the computer 64 calls the computer 12, informs the computer 12 of its status and re¬ ceives a substitute programming schedule and other instructions from the computer 12. Thirdly, upon initial installation, a newly installed computer 64 performs the self-diagnostic routine referred to above. Upon receipt of the time of day and telephone number of the local computer 12, the computer 64 calls the computer 12 to receive a substitute pro¬ gramming schedule and other instructions.

When a serviceman installs the household television control unit 58 in the household 16,20, he normally will call the site of the local computer 12 and inform the site operator of the identification number of the household 16,20 and of the unique seri¬ al number of the control unit 58 being installed. The operator will then enter the serial number of the control unit 5a into the database of the computer 12 at which time it will be uniquely associated with the identification number of the household 16,20 in which it has been installed. The serviceman should then place the control unit 58 in an operative condition, at which time the computer 64 performs the above- mentioned power-up routine.

The following is illustrative of one of many different formats that may be used in transmit¬ ting information between each computer 64 and the local computer 12. Basically, when calling the com¬ puter 12, each computer 64 transmits .at least three types of messages: a prologue and status message, substitute programming cut-in information messages and channel change messages. The prologue and status message normally proceeds all data transmissions by a computer 64 to the computer 12 and is a multibyte message containing the following information. The initial two bytes contain the unique serial number of the household television control unit 58 making the call to the computer 12. The following four bytes represent the number of seconds from a fixed time reference, such as midnight of the first day of the year, since the control unit 58 was last energized. This information may be used to check the integrity of the transmitted data. The next four bytes of data indicate the number of seconds since the time of the last call of the control unit 58 to the computer^' 12. This data is used as a reference for the time set forth in the channel change and substitute program¬ ming cut-in messages. The following four bytes of data set forth the current date and time in seconds to ensure that the clock 68 is accurate. The next four bytes of data represent the purpose of the call being made and the status of the control unit 58. Specifically, the first byte represents the purpose of the call being made, the second byte indicates whether a non-caole household 16 or a cable household 20 is reporting and the remaining two bytes are used to indicate error conditions within the computer 64. The next four bytes of information indicate the num¬ ber of substitute programming cut-in message packets (a data stream transmitted over the telephone line as a unit) and the number of channel change message packets to be transmitted during the telephone call.

By. grouping the data to be transmitted over the telephone line from the computer 64 to the com- puter 12 into individual message packets, data trans¬ mission reliability is improved. Each packet groups data records into a uniquely identifiable entity that may be easily handled and verified by the computer 12. The computer 12 can identify transmission errors as they occur and request the computer 64 transmit¬ ting the information to retransmit improperly trans¬ mitted message packets. Each message packet includes three parts: a header, the data records and an error checking word. The header may be five bytes of data, the first byte identifying the length of the header and the data, excluding the error checking word, another byte identifying the type of data records that are being transmitted and another two bytes identifying the particular number of the message packet then being transmitted. When all of the mes¬ sage packets of a particular type have been sent, a byte is used to indicate "end of data". The packet number is identified so that interrupted telephone communications can be resumed where they left off.

Following the header, the data records are transmitted. Typically, the prologue and status mes- sage will have only one record per message packet. The substitute programming cut-in data typically will have twenty records per message packet; and the chan¬ nel change information typically will have thirty records per message packet. Following the transmis- sion of the data records, a two byte error checking word is transmitted.

A suitable format for transmitting each substitute programming cut-in data record is a mul¬ tibyte data stream in which the initial two bytes identify the substitute programming transmitted to the television receiver 50, the following byte iden¬ tifies the channel to which the television receiver 50 was tuned at the time the substitute programming cut-in was made and the following three bytes relate the number of seconds^' since the time specified in the prologue and status message described above.

A suitable format for transmitting each channel change data record is a multibyte data stream in which the initial byte indicates the channel to which the television receiver 50 has been changed and the following three bytes relate the number of seconds since the time specified in the prologue and status message. Preferably, the computer 64 is pro¬ grammed to inhibit the recordation of _^channel change information unless the television receiver 50 is tuned to a particular channel for a predetermined number of seconds before a channel change occurs, ex¬ cept in the instance where a substitute programming cut-in occurs prior to the expiration of the prede- terrained number of seconds. When the television re¬ ceiver 50 is initially turned on, the event is re¬ corded as a change to the channel to which the tele- vision receiver 50 is tuned. When the television re¬ ceiver 50 is turned off, that event is recorded as a change to channel zero.

A set of rules or protocol is used to transmit data between each computer 64 and the local computer 12. The protocol directs data flow in an orderly manner and provides for error checking. When the preassigned time arrives for a computer 64 of a control unit 58 in a particular household 16,20 to call the local computer 12, the computer 64 enables the mode /automatic dialer 80 to dial the telephone number of the computer 12. If an access line to the computer 12 is available, the computer 64 transmits properly formatted data records grouped into separate message packets. When the computer 64 has transmit¬ ted all- of its message packets, it then receives a substitute programming schedule and other information from the computer 12 for storage and use during the following broadcast period. The substitute program- ming schedule and any other information from the com¬ puter 12 are transmitted via message packets. After all of the message, packets have ύeen received by the computer 64, the telephone connection is broken.

When the computer 64 of the control unit 58 calls the computer 12, it thereby establishes the control unit 58 as the message 'sender and the com¬ puter 12 as the receiver using a "handshake" proto¬ col. The handshake is one byte of data transmitted back and forth which indicates the mode of data transmission. After the first handshake byte is transmitted, the computer 64 transmits a message packet to the computer 12. At the completion of the transmission of that message packet, the computer 12 transmits a byte indicating the message packet as re- ceived was correct or incorrect. The computer 12 may reverse the protocol by requesting to send data, for example, substitute programming information, to the computer 64.

The telephone connection between each com¬ puter 64 and its associated local computer 12 is de- signed to be transparent to the household 16,20. Thus, if a member of the household 16,20 initiates usage of the telephone 78 during the transmission of data over the telephone 78, the connection between the computer 64 and the computer 12 is automatically broken and may be restored at a later time when the telephone 78 is -not being used by a member of the household 16,20. Upon restoration of the telephone connection between the computer 64 and the computer 12, the transmission of data is resumed with the in- terrupted message packet.

Upon a power interruption to the computer 64, the information stored in the memory unit 70. may be lost. After power is restored, the computer 64 performs the power-up sequence discussed above. If a large power outage has occured, the phone network servicing the computer 12 may be overloaded by a large number of computers 64 attempting to establish contact with the computer 12. To avoid this, each computer 64 is preprogrammed to' delay calling the computer 12 by a random time delay. In addition, if a busy signal is received, the computer 64 will make another attempt to call the computer 12 after the programmed random time delay. A telephone line failure which would prevent a computer 64 from con- tacting the computer 12 shows up as a malfunction in the records of the computer 12 which should expedite the repair of the telephone line. Similarly, if a household television control unit 58 or its computer 64 is damaged, disconnected or removed from a house- hold 16,20, such an event also is indicated as a mal¬ function in the records generated by the computer 12. If the computer 12 malfunctions, each household television control unit 58 is notified by the data por¬ tion of the special television signal broadcast by the microwave transmitter 24 or the satellite 26. The computers 64 of the household television control units 58 can be instructed to take appropriate action to prevent overloading their memory units 70.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example, the com- puter 64 can be programmed to monitor and store on a real time basis the "on-off" condition of a standard mute switch typically associated with the tuner/converters 48,54. This information would be transmitted to the local computer 12 during the preassigned reporting time window using essentially the same format as the channel change messages. This information may then be correlated with the substi¬ tute programming cut-in report to enable marketing researchers to determine whether the substitute pro- gramming, normally substitute commercials, was both being viewed and listened to by the viewing members of the household 16,20. Such information would im¬ prove the accuracy and acceptance of the marketing research test results obtained by means of the system 10. Thus, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described hereinabove.