A Pioneering Experiment in Assessing Advertising Effectiveness THOMAS E. COFFIN According to this article, there are only two basic dimensions to the effectiveness of advertising: (I) size of audience, and (2) depth of impact. The advertising industry has been spending most of its research dollars in measuring the audience component, with the result that we can now measure this dimension reasonably well. Dr. Coffin believes it is now time to spend more dollars in assessing the dimension of impact—for it is this area which, for the future, promises the greatest improvement in advertising evaluation and sound media comparisons. there are only two basics. There are many variINantsadvertising, of each, and many levels at which each can be described and measured. But fundamentally these all reduce to two issues: 1. "How many peoj>le you reach"—audience size. 2. "How hard you hit them"—depth of impact. These two basics apply whether the advertising in question is a single advertisement, a campaign of advertisements, or a medium of advertising. True, there are many refinements and elaborations upon each. Various qualifiers may be appended to the "how many" question. For example, it may be decided that certain kinds of people are more valuable to veach than others—this is "quality" of audience. But this refinement is easily dealt with by differential weighting in the audience counts. Heavy product users, for instance, can he given more weight than light users or nonusers. And the "how many" can be measured at various levels: circulation, readership, viewership, exposures, noting, sponsor identification, for example. Moreover, the measurement can he elahorated to include the frequency, the duplication, the cumulation, the gross reach, and the net reach. But all such measures are still asking basically, "How many?" Obviously audience is the first dimension of advertising, and much time and effort has been spent in improving the various measures of it. But audience figures should be the starting point, not the stopping point, in advertising measurement. Time and effort now should he devoted to measurement of the second dimension, the depth-of-impact factor. Until both factors are included, the advertising industry will continue to be without a proper measure of the effectiveness of its product. This is important for all advertising. Growing advertising budgets are leading top management to press with increasing urgency the question of advertising's effectiveness. And with the advent of computers in the media-selection process, the practical need is becoming more acute for input data on the impact as well as the audience of media. The industry tries to answer management's question by pointing to how many the advertising has reached, of what quality, and with what frequency. Likewise, this is the principal type of data thus far at hand to feed into the computer. But in each instance audience is only half the answer. Three Historical Stages Most people in the advertising business have been curiously reluctant to "face up" to the second half of the question. This has been evident both on the primary issue of measuring adver- Journal of Marketing, July, 1963 tising effectiveness per se, and on the subordinate question of measuring the comparative effectiveness of different media. Looking back, the industry has gone through three interesting stages; Phase 1. For many years, tke accepted view was to deny that it is possible to measure advertising effectiveness. Concerning advertising, per se, the cliche was, "There are too many variables." Concerning the comparison of media, "You can't compare apples and oranges; they differ too much." But pressure from management continued, eventually leading to Phase 2. Phase 2. Hesitant agreement that further measurement is needed. But with continued reluctance to address the "effectiveness" issue directly, the measurement became diverted into amplifications of qualitative attributes: preoccupation with kinds of audiences, numbers of exposures, reading days, page openings, frequency breakdowns, quintile analyses. This was the diversionary phase, pursuing attractive bypaths while avoiding the main issue. Phase 3. The period of acquiescence. With pres- sure from top management more intense and with increasing concern over the "profit squeeze"—plus the arrival of the computers, generating additional pressures with their appetite for explicit figures—industry opinion is at last swinging toward an affirmative interest in the measurement of advertising effectiveness. Four recent publications have clearly pointed up this trend.* A Point of Perspective Under this changing climate of opinion it may be wise to inject a cautionary note oi historical perspective. It has taken audience researchers some three decades and upwards of a hundred million dollars spent on audience research of all varieties to arrive at the point where they can produce reasonably accurate answers to the question of "how many." It would seem likely that it may take nearly as long, and as many dollars, to make comparable progress on the more difficult question of "how hard." With this frame of reference, it is evident that the following case-history is not regarded as representing perfected techniques or ultimate Toward Better Media Comparisons, A Report of the Audience Concepts Committee of the Advertising Research Foundation {New York: Advertising Research Foundation, Inc., 1961). Russell H. Colley, Defining Advertising Goals for Measured Advertising Results (New York: Association of National Advertisers, Inc., 1961). Harry Deane Wolfe, James K. Brown, and G. Clark Thompson, Measuring Advertising Results (New York: National Industrial Conference Board, 1962), Darrell Blaine Lucas and Steuart Henderson Britt, Measuring Advertising Effectiveness (New York: McGraw-Hill Book Company, Inc., 1963). answers. Growing out of a long-standing interest in the assessment of advertising effectiveness and successive attempts at improving the methods employed,^ this study represents an experimental investigation which a few years ago undertook to extend our efforts into the as yet untried area of inter-media effectiveness comparisons. The methodology outlined may prove of interest and provide some stimulation for further exploration, while revealing some of the problems encountered in assessing advertising impact and some attempts which have been made to deal with them. An Experimental Study This experiment was a 2-wave panel study, in which the same individuals were reinterviewed at two points in time three months apart. The sample was a prelisted probability sample, representing a typical medium-sized midwestern market; 91% of the original respondents were recovered on Wave II. The respondents were male and female household heads, with a final sample size of 2,441. The study covered 22 brands advertised both on network TV programs and in weekly Magazine A, representing 11 different product categories: Beer Canned soup Cigarettes Gasoline Headache remedies Deodorants Home permanents Packaged cheese Packaged desserts Razor blades Toothpaste Thomas E. Coffin, Tke Hofstra Study: A Measure of the Sales Effectiveness of TV Advertising (New York: National Broadcasting Company, Inc., 1950). TV Today: Its Impact on People and Products (New York; National Broadeasting: Company, Inc., 1951). Why Sales Come In Curves (New York: National Broadcasting Company, Inc., 1954). Strangers Into Customers: Tke Fort Wayne Study (New York: National Broadcasting Company, Inc., 1955). • ABOUT THE AUTHOR. Thomas E. Coffin is Director of Research of the National Broadcasting Company, Inc. The concepts in the present article have been developed in the course of analyzing a series of major studies into the effectiveness of television advertising, conducted by NBC over the past several yea rs. Prior lo joinrng NBC tn 1949, Dr. Coffin was Professor of Psychology and Chairman of the Psychology Department at Hofstra College. He received his M.A. and Ph.D. in Psychology from Princeton Vnlvers'dy. Jack 8. Landis, formerly Manager of Research Projects at NBC and now Executive Director of Marketing Evaluations, has contributed greatly to the development of the ideas and technicfues described in this article. A Pioneering Experiment in Assessing Advertising Effectiveness For each of these categories the respondent was questioned as to what brands he or she had "personally bought in the last four weeks." The "buying figures" to follow, therefore, represent the percentage of the total sample (or specified subgroup) who claimed to have bought the advertised brand in the last four weeks. In the TV viewing question, a list of programs was shown and the respondent was questioned ahout his personal viewing of each in the last four weeks. In the case of weekly magazines, a list was also used, with the questioning directed toward the last four issues. "Readers" or "viewers" here are those who claimed to have read one or more of the last four weekly issues or watched one or more of the last four broadcasts. Thus, in the following sections the unit of exposure is the advertising vehicle, rather than the commercial or advertisement. To maintain comparability, the same questionnaire wordings and sequences were employed on both waves of the study. To minimize any possibility of the buying responses being infiuenced by the media questions, these topics were separated as widely as possible, so as to obtain the information about buying before asking about media exposure, with a number of other questions intervening. Moreover, several additional products, programs, and magazines were included in the lists, in order to divert attention further from the questions of special interest and to lessen the chance of producing a spurious relationship between a particular product and a program or magazine. Careful analysis of previous studies has shown that such precautions have been effective in minimizing the possibility of inadvertent "reversal" of cause and effect or of "conditioning" the responses on Wave II by prior questioning on Wave I.-^ Results All of the figures to be reported represent the unweighted averages of the 22 brands studied. Inspection of the individual brands indicates that these averages properly reflected the experience of the majority of the individual brands; about 75% of the individual brands showed the same patterns as those pictured by the averages, while 25% of the brands deviated from the average pattern in one way or another. As shown in Table 1, the first overall finding of the study was that, on a total sample basis, there was remarkably little difference between the buying levels for Wave I and Wave II. The 3 Why Sales Come In Curves (New York: National Broadcasting Co., Inc., 1954), pp. 51-52. Strangers Into Customers: The Fort Wayne Study (New York: National Broadeasting Co., Inc., 1955), p. A-7. TABLE 1 SOME RELATIONSHIPS OP BUYING TO OVERALL ADVERTISING EXPOSURE 1. Overall results of survey Total sample. Wave I Total sample. Wave II % buying in past 4 weeks 19.4 19.6 2. Relationship of buying to advertising exposure % buying, Wave II Exposed to advertising (TV and/or magazine) 20.5 Not exposed to advertising 16.9 3. Relationship of buying to degree of exposure % buying, Wave II Not exposed to advertising (TV and/or magazine) 16.9 1 unit of exposure (TV and/or magazine) 18.9 2 units of exposure. <TV and/or magazine) 20.1 3 units of exposure (TV and/or magazine) 21.8 4 units of exposure (TV and/or magazine) 24.0 percentage buying the "average brand" in the last four weeks was 19.4 for Wave I and 19.6 for Wave II, three months later. It might seem that nothing is happening. This appears to support the view that "you cannot relate advertising to sales," since a good deal of advertising for these brands occurred in this period. This pattern, of minimal change in overall levels from one period to another, is a common finding in panel studies. However, if we start breaking the total sample apart into its component groups, we begin to find evidence that something is going on. For example, if we break out those who are exposed to advertising for these brands (any type, either television or magazine) as compared with those not exposed, we note an appreciable difi^erehce in their buying levels on the second wave: 20.5% va, 16.9%. And going further, if we analyze the exposed group by degree of exposure, we begin to see a trend. The more units of advertising a group la exposed to, the higher its buying level on Wave II (where exposure to one medium at one period equals one unit). By Wave II, there was a 42% spread between the levels of the least-exposed and most-exposed groups. Changes in Exposure One of the most useful features of true panel data, where the same individuals are interviewed over successive periods of time, is the opportunity they afford for "dynamic analysis," the study of change. The possibility of detecting significant Journal of Marketing, July, 1963 relationships is enhanced when people are observed in the process of change. In the present case, analysis of respondents in terms of changes in their advertising exposure revealed that changes in exposure were associated with changes in buying. Respondents who experienced an increase in exposure (to either form of advertising) showed an increased level of buying; with no change in exposure, there was no change in buying level; and with decreased exposure came decreased buying. See Table 2. The Increased Exposure group consisted of those respondents who reported more units of exposure on the second interview than on the first. The No Change group were those who reported the same numbers of units both times. The Decreased Exposure group were those who reported more units on Wave I than on Wave II; thus, at the time they were more heavily exposed, their buying level was higher, and when they became less exposed, their buying level became lower. A Master Table presenting the detailed breakdowns of all results, together with the number of cases in all subgroups, is given in Table 7, page 9. There the Increased Exposure groups have been further broken down into groups C, I, K, L, and O. The No Change groups are A, D, G, J, M, P. The Decreased Exposure groups are B, E, F, H, N. Buying Dynamics Dynamic analysis may be applied to the dependent as well as the independent variable. Examination of the "buying dynamics" enables us not only to measure changes in levels, but to perceive the mechanism whereby these changes come about. Those who were buying on Wave I can be divided into two components. Some were still buying the same brand on Wave II three months later; they may be termed the "continue buying" group. Others reported not buying this brand on Wave II; these are the "stop buying" group. Likewise, among those who were not buying the brand on Wave I, some will be found buying it on Wave II ("start buying") ; and others are still not buying it ("nonbuyers"). Do these buying dynamics bear any relation to changes in advertising exposure? They certainly do, in a most interesting pattern—see Table 3. Among those whose exposure to advertising increased, more people started buying than stopped. TABLE 2 RELATIONSHIP OP BUYING TO CHANGES IN ADVERTISING EXPOSURE Increased exposure No change in exposure Decreased exposure % Buying Wave I Wave II 19.6 21.0 20.3 20.4 21.0 19.4 Relative change +7% 0 -8% TABLE 3 BUYING DYNAMICS AND CHANGES IN EXPOSURE Increased exposure No change in exposure Decreased exposure % stop buying % con tinue buying % start buying 8.0 8.1 9^ 11.6 |l2.2 11.6 |9.4 8.2 7.8 Indeed, this group showed the strongest tendency of any of the three groups to "start buying." Those with no change in exposure were marked by a somewhat higher rate of "continuing" to buy. And the most notable tendency among those with decreased exposure was to "stop buying"; in fact, they stopped buying at a 20% greater rate than they started. (Note that these figures are additive. Checking back with Table 2, it will be seen that the Stop plus Continue percentages add back to the buying level on Wave I, while the Continue plus Start figures add to the Wave II level.) These relationships are highly suggestive of the double functions of advertising: "generation" and "preservation." Often advertising is thought of for its value in inducing people to start buying a brand, generating new customers; but the figures above suggest its value additionally in persuading present buyers to continue, thereby preserving old customers and reducing the number of "lost customers." Thus, in a situation where the overall buying levels appeared static, it is seen that intriguing dynamic changes—stopping, starting, switching— were going on beneath the surface, and that these buying changes had a meaningful relationship to concurrent changes in advertising exposure. The dynamic associations between shifts in exposure and shifts in buying, while not "proof" of a causeand-effect sequence, strongly suggest an interrelationship between the two processes. They suggest that advertising "works" and imply something of "how" it works. Relationships to Individual Media Thus far the analysis has been in terms of exposure to advertising per se, regardless of type. It may be useful to pursue this further, examining some of the relationships to individual media. The reminder is again in order that the following figures should be regarded as being of methodological rather than substantive interest. Their purpose is not to represent a thoroughgoing attempt at assessment of the relative effectiveness of the two media, but simply to suggest some of the possible analytical approaches for such comparisons. A number of limitations in the present study prevent it from being considered a full-scale inter- A Pioneering Experiment in Assessing Advertising Effectiveness media comparison: the study is restricted to a single market; it covers only two types of advertising, without reference to other media which may have been used; the measures of exposure and buying are on a verbal-report basis, without verification by pantry-checks or more elaborate audiencemeasurement techniques; no attempt has been made to relate results to the costs of advertising; and the study covers only a cumulative series of exposures, making no effort to determine the effects of a single advertisement or single broadcast, nor to assess the effects of varying frequencies of exposure. Some of these limitations have been successfully attacked in other studies by the National Broadcasting Company.^ They are not insurmountable in future research, but their presence should be kept in mind. "Before" and "After" Exposure With tbese cautions in mind, it is of interest to examine some of the ways in which a 2-wave panel survey can be analyzed to yield indications of media effectiveness. The most interesting analyses are those whieb take advantage of "turnover," that is, the changes which are continually going on in the audience to any medium. Here we apply to audience the same kind of "dynamic analysis" previously applied to the buying process. Let us start with the population of people not exposed to a given medium (for example, a television program) at the time of the first survey. These same individuals can then be followed through on Wave II. Thanks to the phenomenon of audience turnover, it will be found that some of them were in tbe exposed category at the time of Wave II (that is, they have "begun viewing"). This is a particularly significant group, because they provide cases on which we now have buying records "before" and "after" exposure. And since The Advertising Impact of TV Specials (New York: National Broadcasting Company, Inc., 1957). Hardgoods and the Impact of Television (New York: National Broadcasting Company, Inc, 1960). Introducing New Cars on Television (New York: National Broadcasting Company, Inc., 1960). tbe group is made up of precisely tbe same people both times, all variables of a personal and demographic nature which might influence the buying process are held constant. Similarly, the remaining segment of the population not exposed on Wave I is a very useful group: they comprise the people who did not "begin viewing," thus serving as a control for those wbo did begin viewing. The comparison of these two groups is especially significant in that botb of them came from the same population on Wave I. Starting from the same condition of nonexposure, we can then follow them as one group becomes exposed and the otber does not—what happens to their buying? Table 4 shows these buying levels. Taking, for example, the case of television viewing, tbe first two lines give the ieveis for all those who were not exposed on Wave I. Of these, the ones who "began viewing" showed an increase of 10% in the number buying the brand advertised on the program they began viewing (again, this is the average of 22 brands, each tabulated against the viewing of its own program). Those who also started as nonviewers but remained nonviewers showed no change in buying. Tbe converse of the foregoing analysis is also of interest. If we start with all those who were exposed to a given medium on Wave I and trace them through, we find that audience turnover occurred in this group also. Thus, some of the group were in the exposed category on Wave II as well as on Wave I (that is, they "continued viewing"). And others were in the nonexposed grOup the second time (they "stopped viewing"). So again we have available two subgroups derived from the same Wave I population. Both were viewers (or readers) at a given point in time. Some continued, and some did not. What happened to their buying behavior? Certain hypotheses can be formulated as to what might be expected under these conditions. Given a group which is exposed to begin with, and continues its exposure, it would be a reasonable hypothesis that if advertising is effective, such a group should show a high initial level on the first wave TABLE 4 "BEFORE" AND "AFTER" EXPOSURE TO SPECIFIC MEDIA % Buying Wave I Television: Nonviewers who . . . . . . became viewers . . . remained nonviewers Magazine: Nonreaders who . . . . . . became readers . . . remained nonreaders Wave II Relative change 18.7 18.0 20.6 18.0 -M0% 20.5 19.2 21.0 19.8 +3% +3% 0 Journal of Marketing, July, 1963 TABLE i5 MAINTAINING VERSUS REDUCING EXPOSURE TO SPECIFIC MEDIA 9;? Baying Wave II Wave I Television: Viewers who . . . . . . continued viewing . . . stopped viewingMagazine: Readers who . . . . . . continued reading . . . stopped reading (associated with its Wave I exposure) and maintain this high level on the second wave (in keeping with its sustained exposure). As shown in Table 5, this is in fact what happened in the case of the viewing group. Similarly, the hypothesis would be that a group which is initially exposed, but subsequently ceases its exposure, should again start at a high level (under the condition of exposure) but drop to a lower level (when no longer exposed). This, too, is what happened to the viewing group. This phenomenon of a drop in buying level associated with a reduction in advertising exposure distresses some in the advertising field, on the ground that it seems to have "negative" implications. Quite to the contrary, it is important evidence of advertising effectiveness. If one hypothesizes that buying levels should rise under increasing advertising pressures and remain high under continuing- pressures, then he must also hypothesize that under decreasing pressures, they will fall. The latter is a necessary corollary of the former. And the more effective is the medium, the greater should be the decline if its pressure is reduced. Consequently, in investigating the effectiveness of advertising this test rounds out the full circle of testable hypotheses. Indeed, as a practical matter, if this did not prove to be true, why should anyone, once he had achieved a satisfactory level, continue to advertise? A 16-Fold Analysis The above analysis is capable of still further improvement. Each medium was treated above as though it were independent of the other. But in actual fact some of the "viewers" were also "readers," and some of the "readers" were "viewers." Hence, the analysis must cope with the phenomenon of audience duplication. Possible Advertising Strategies: A Model To approach the problem systematically, let us start by laying out all the possible conditions which may be encountered in dealing with two different media at two different points in time. Taking one of the media first (for example, maga- 23.0 21.6 23.2 19.2 21.7 19.9 20.9 19.4 Relative change + 1% -11% -4% zines), there are four—and only four—conditions of exposure which can obtain across two points in time. Using a plus sign to signify exposure and a minus sign for nonexposure, the four possibilities are: f- Not exposed on I, exposed on II ("start reading") + -\- Exposed on both occasions ("continue reading") + — Exposed on I, not on II ("stop reading") ~ — Not exposed either time ("non-reading") The same four exposure groups—and no more— can be laid out for the other medium. We have already examined these four groups for each medium taken separately (Tables 4 and 5). But when the two media are considered simultaneously, it is evident that there are 4 times 4, or 16, possible exposure conditions. In conjunction with each one of the TV groups (for example, "start viewing") it is possible to have any one of the four magazine-exposure situations ("start," "continue," "stop," or "no" reading), and vice versa. These 16 possible situations are represented in Figure 1. An intriguing aspect of this chart is that it also turns out to be a systematic layout of all the possible advertising strategies that could be followed—a "model," as it were, of all the possible decisions which could be made by an advertising manager under the restriction of two media at two points in time. The data from a 2-wave survey can be analyzed according to this model. Since each respondent will be found to fall into one, and only one, of the 16 exposure groups (and these 16 groups account for all respondents), the 16 groups can be broken out and their buying levels and changes tabulated. For completeness, this "master table," setting forth the full results of the present survey, is shown in Table 7. However, in the interests of simplicity some of the more meaningful comparisons are presented for easier examination in Table 6. Each group in Table 6 is keyed by letter to the corresponding line in Table 7. A Pioneering Experiment in Assessing Advertising Effectiveness Magazine Compaign _ I Start start Both -+ +StortTV Keep Mag. + + - + + -I- + + S Keep TV Start Mag. Continue Switch from Mag. to TV Switch from TV to Mag. __ __ „ ^ Keep TV StopAlag. No TV Start fAag. None FIGURE 5top Both Stop TV KeepA\ag. -" -I- + No TV Keep Mag. Start TV No fAa^. ++ +- + + Keep Both + - + + + - -HStop None +- -+ - + „ , , I. Stop Continue Start _ .^ Keep TV No Mag. +Stop TV No Mag. 1, . No TV Stop Mag. No Advg. 1. Possible advertising strategies: A model- Possible Advertising Strategies: Their Relationship to Buying Following are some of the more interesting comparisons which can be drawn from the complete breakout of results of such a 2-wave, 2-media survey. Such comparisons not only take proper account of but even take advantage of the duplication and nonduplication between media, as well as of the changes in exposure to the media (stops, starts, and switches) in order to raise for examination various hypotheses regarding the effectiveness of advertising in general, and of the two media in particular. To render the exposure symbolism somewhat more meaningful, each of the groups is tagged with a descriptive phrase indicating the "advertising analog" which it represents. Thus, each group can be thought of as representing, in a sense, a "simulation" of an interesting advertising strategy. However, there are definite limitations to such analogies, in that here the exposure-condition is brought about by self-selection on the part of the respondent, rather than having been experimentally imposed from without by the investigator. Moreover, the principal focus is not on the substantive content of the figures themselves, which represent only the findings of a single study done a few years ago in a single market, but on illus- trating one possible approach to the investigation of advertising effectiveness and intermedia comparisons. For each group in Table 6 are shown the buying levels on Waves I and II and the change from I to II, plus the "buying dynamics" which generated these levels. As a visual aid in noting points of special interest, all comparisons showing a spread of 2 or more percentage points are enclosed. Thus, in the first comparison the most noteworthy difi'erence is that the group exposed to TV-only both times showed an unusually high "continue-buying" rate, plus a higher "start-buying" rate than the magazine-only group. However, in the second comparison the group which switched from TV to magazine exposure showed more "continue-buying" than those who switched from magazine to TV exposure. By pairing the appropriate groups, it is possible to set up a comparison in which one medium remains constant, while the other is varied. Comparison 3, for example, brings together the two groups who maintained exposure to one medium while reducing exposure to the other. Reduced exposure to TV seemed to have more effect on the buying level than reduced magazine exposure; this resulted from the fact that with reduced TV went a lower rate of "starting" to buy and a higher rate of "stopping." Journal of Marketing, July, 1963 TABLE 6 EELATIONSHIPS OP POSSIBLE ADVERTISING STRATEGIES TO BUYING Group TV Magazine 1 Advertising analog 1. A continuing campaign in a single medium D + + A continuing TV-only campaign M —_ + + -A. continuing Magazine-only campaign 2. Switching campaigns from one medium to another Switch from Magazine to TV J - + -]— G + - + Switch from TV to Magazine 3. Dropping a cwm-paign B - ! - + + _ Keep TV but drop Magazine Keep Magazine but drop TV E -H + -H 4. Starting a campaign O ++ Start Magazine campaign, no TV L - + • — Start TV campaign, no Magazine K - 4- - -1-1- Start campaign in both 5. Extremes of change in advertising strategy K — •\- — -f Start campaign in both media F + — + _ Drop all advertising 6. Extremss of advertising weight A + + + 4 - Continuous advertising in both media P No advertising in either Comparison 4 presents the reverse case, comparing the two groups who remained nonexposed to one medium, while increasing, their exposure to the other. Increased exposure to TV seemed to have the greater effect, due chiefly to the greater rate of "start-buying" in this group. However, the greatest change of all is observed in the group which increased exposure to both media. Here the buying level increased markedly, again principally as a result of more "start-buying." Comparison 5 contrasts the extremes of change in advertising exposure, comparing those who "started" both media with those who "stopped" both. When both media were working together the "starts" went up (due to high "start-buying"), and the "stops" went down (due to high "stopbuying"). The final comparison contrasts the extremes of advertising pressure: full exposure to both media, compared with absence of exposure. Here, witb relatively constant advertising exposure, one does not hypothesize change in buying, but differences in levels of buying. And that is what happened. The continuously exposed group was buying at a continuously higher level—and the difference was due to their much higher rate of "continuing to buy," with this group showing the highest percentage of "loyal customers" of all 16 exposure groups. Thus, the analysis seems to "make sense," and to document the value of advertising in terms which management could readily appreciate. Although on % buy brand // Change Buying dynamics Continue Stop Start 21.8 19.3 23.0 18.7 1.2 -.6 14.2 11.9 7.6 7.4 8,8 6.8 18.6 22.5 18.8 20.8 .2 -1.7 9.4 12.4 9.2 10.1 9.4 8.4 22.2 23.2 23.0 19.8 -3.4 13.8 12.7 8.4 10.5 9.2 7.1 17.7 18.1 17.6 18.0 20.9 21.7 .3 2.8 4.1 9.9 11.1 10.2 7.8 7.0 7.4 8.1 9.8 11.5 17.6 19.7 21.7 17.6 4.1 -9.A 10.2 9.9 7.4 9.8 11.5 7.7 23.7 16.0 24.0 16.9 .9 16.1 9.3 7.6 6.7 7.9 7.6 .8 an overall, total-sample basis the buying levels appear to remain static and little seems to be happening, on breaking out the interrelationships between exposure and buying, it is found that movement and change is going on. And these changes relate to advertising exposure in meaningful ways. Under increasing exposure, more people start buying, and buying levels rise. Under decreasing exposure, more stop buying, and buying levels fall. Under continuing' advertisingpressure, more continue buying, and levels remain high. And finally, different media can be examined to see which are associated with these effects to a greater and which to a lesser degree. Further Improvements Desirable We have carried the analysis of this case-history through several successive levels of refinement, each of which has considerably improved it. However, the process of improvement is not by any means complete. The fundamental objective in all "effects" comparisons is to confront what did happen in a given circumstance (for example, under the influence of a given advertising strategy) with what would have happened, if that circumstance had not obtained. The difference, all other things being equal, is the "effect" of that circumstance. Since the "did happen" is known, the problem is always to find the "would have happened." In the present case, for example, there may still A Pioneering Experiment in Assessing Advertising Effectiveness TABLE 7 MASTER TABLE, SHOWING COMPLETE RESULTS FOR BOTE[ WAVES* Exposure Group TV Magazine 24.0% 23.0 23.3 23.0 16.1% 13.8 13.7 14.2 23.2 Keep Magazine, drop TV Drop all advertising 19.7 Substitute Magazine for TV campaign 22.5 No Magazine, drop TV 21.0 19.8 17.6 20.8 18.5 12.7 9.9 12.4 11.3 10.5 9.8 10.1 9.7 7.1 7.7 8.4 7.2 70 55 49 147 7.8 9.4 11.5 9.8 60 39 56 137 analog A E C D -j- -{- + -t— — + — + — Continuous advertising in both media Keep TV but drop Magazine Add Magazine to TV campaign Continuing TV-only campaign E F G H -f — + -f — — + — + — I J K L ^ M — — N 0 P 23.7% 22.2 24.2 21.8 + + -1 — + — — Add TV to Magazine campaign Substitute TV for Magazine campaign Start campaign in both media Start TV-only campaign 20.5 18.6 17.6 18.1 21.0 18.8 21.7 20.9 13.2 9.4 10.2 11.1 7.3 9.2 7.4 7.0 + + — — Continuing Magazine-only campaign No TV, drop Magazine Start Magazine-only campaign No advertising in either Total (weighted) 19.3 18.8 17.7 16.0 19.4% 18.7 18.2 18.0 16.9 19.6% 11.9 10.4 9.9 9.3 11.5% 7.4 8.4 7.8 6.7 7.9% + — -i— Start No. in Stop buying 7.6% 8.4 10.5 7.6 Advertising % buy' brand Continue Wave I Wave II buying buying 1.9% 9.2 9.6 8.8 6.8 7.8 8.1 7.6 8.1% group 158 86 101 290 228 151 197 617 2441 * Each figure is the average of the corresponding figures for 22 different brands. remain some variance between the groups being compared, due to differences in their composition and makeup (that is, "all other things" are not yet equal). In the search for further methodological improvement in future studies, one of the most promising, tools with which to attack this problem might be multiple regression analysis, with large numbers of variables handled simultaneously. Implications It was our initial thesis that there are two basics in advertising, reach and impact. The significance of this observation, however, goes well beyond the mere naming of two factors. If each of these factors could be measured and reduced to a number, and if these two numbers were multiplied together, the resulting product would be a third number which would have the highly significant property of being a true measure of the total effectiveness of the advertising in question. Thus, the two factors of audience and impact represent far more than simply different emphases in evaluating advertising. They represent the two necessary and sufiicient conditions for performing a true measure of advertising effectiveness.^ As such, they are capable of formulation in a simple but powerful equation. The total effectiveness of advertising is the product of size of audience multiplied by impact per member of the audience: E = A X I See Thomas E. Coffin, '"Total Effect' Concept in Media Comparisons," Media/scope Vol. 3 (February, 1959), pp. 44-48 and 52. This equation is applicable both to the problem of measuring the effectiveness of any single advertisement or campaign, and to that of properly comparing different advertising media. In the latter application, it effectively solves the "apples-andoranges" dilemma in media comparison. It is indeed true that a "reader" and a "viewer" may be worth different values and should not be compared. But if the impact per reader could be measured, and multiplied by the number of readers, the product would represent the total effect of the reading. By putting each medium through the same process, all would be converted to the same terms and become comparable. Thus, the end-products of the effectiveness equation are comparable, although the separate components are not. The effectiveness equation also has the property of being self-adjusting for differences in the level at which the audience factor is measured. Thus, if a "loose" definition of audience is used, audience size will be large; but due to the inclusion of many "lightly-exposed" people, the impact per person will be small. The product of these two will be similar to that obtained from a "tight" definition, yielding a smaller audience but a correspondingly higher impact factor. Since a key problem in the comparison of media has been how to define their audiences with equal "tightness," this self-adjusting property of the effectiveness equation is a major benefit. A great deal remains to be done, of course, before such an ideal procedure can become a matter of daily practice. "Audience times impact" yields a true measure of total effectiveness, but the precision 10 Journal of Marketing, July, 1963 of final figure is a direct function of the precision with which each of its components is measured. At present, the precision of audience measures far exceeds that of impact measures. The advertising industry has been spending most of its research dollars in measuring the audience component, with the result that we can now measure this dimension reasonably well. It is now time to start spending more dollars in pursuing the measurement of impact, for it is this area which in the future promises the greatest improvement of overall efficiency in advertising evaluation. MARKETING MEMO Factors Leading To Inventiveness . . . Inventiveness appears to emerge from situations where personal and social conditions of the following types are encountered: high drive (ambition); frequent marginalism; high relationism; and high operationalism. By high drive is meant that cultures and individuals of high inventiveness make strong demands of their environment, have high hopes and expectations, and value persistence in endeavors. By frequent marginalism, we mean that uncommon views, deviant personality types, and conflicting Weltanschauung are endemic in the inventive culture and express themselves through inventive individuals. Relationism is defined as the ability to perceive connections of all kinds among things and events; it is needed in greater degree for newly combining relations, the salient feature of the invention. High operationalism denotes the strong tendency to regard fulfillment of an idea as requiring- its expression in activity. —Alfred de Grazia, "Elements of Social Invention," The American Behavioral Scientist (December, 1961) p. 8. Reprints of every article in this issue are available (as long as supply lasts) at the following prices: Single reprint Two reprints Three reprints $1.00 1.50 l.SO Four to 99, each First 100 Additional lOO's $ .50 40.00 20.00 Quantity Discount Special prices for large quantities. Send your order fo: SAMUEL N. TURIEL & ASSOCIATES, INC. 333 North Michigan Avenue, Chicago 1, liiinois Duplication, reprinting, or republication of any portion of the JOURNAL OF MARKETING is strictly prohibited unless the written consent of the American Marketing Association is first obtained.