Author and Title Subjects .lQ. Gerbner Violence in Television Drama: Trends and Symbolic Functions 20. Greenberg Television's Effects: Further Explorations 21. Greenberg, Eriaon & Vlahos Children's Television Behaviors as Perceived by Mother and Child 22. Greenberg 81 Gordon Perceptions of Violence in Television Programs: Critics and the Public 23. Greenberg 81 Gordon Social Class and Racial Differences in Children's Perceptions of Televised Violence 24. Greenberg & Gordon Children's Perceptions of Television Violence: A Replicetion 25. Gurevitch The Structum and Con- tent of Television Broadcasting in Four Countries: An Overview B5.4th and Sth grada children and their mothers 53 critics 303 men and women 325 fifth grade boys 89 low SES white 89 low SES black 90 middle SES white 57 upper SES white 263 eight grada boys 66 low SES black 78 low SES white 37 middleSES white 82 upper-middle SES white Description This study provided an analysis of the content of a one week sample of prime- time, entertainment programming. It described various factors relating to the frequency and symbolic characteristics of televised violence. An overview of several current research projects that provide a diversity of theoretical and methodological approaches to research on the effects of television. Mothers, interviewed at home, were asked to describe their child's television viewing patterns (e.g., program praferences, rules about viewing) while each child answared similar questions in the dassroom. The child's salf reported television viewing behavior was compared with the mother's description. A telephone survey ipublic) and mail questionnaires (critics) asked the respondents to rate the amount of violence contained in various television entertainment programs. This study assessed boys waluation violenca portrayed on television in terms of the degree of perceived violence, acceptability of violence, liking, degree of arousal, and perceived reality of the violent act. A replication of the prior study conducted with youngar boys Bee item #23). An introduction to a rev&w of the broadcasting policies of Great Britain, Israel, Sweden, and the United States. Author and Title Subjects 26. Halloran & `Croll Television Programmas in Great Britain: Content and Control 27. Johnson, Friedman & Gross Four Masculine Styles in Television Programming: A Study of the Viewing Preferences of Adolescent Males 80, 8th grada boys 39 "aggressive" 41 "non-aggressive" 28. Katzman Violenca and Color Television: What Children of Different Agss Learn 240,4th, 6th and 9th grade boys 29. Kenny Threats to the Internal Validity of Cross-Lagged Panel Inference, as related to "Telwision Violence" and Child Aggression: A Follow-up Study 30. Lefkowitz, Eron, Walder, (I Huesmann Television Violence and Child Aggression: A Follow-up Study 875 children-third grade sample 382 adolescantaighth grade sample 427,lQ year-olds 31. Leifer & Roberts Children's Responses to Television Violenat Description A discussion of television broadcasting in Great Britain. This study compared the program preference patterns of boys with a history of "social aggressiveness' with their non-aggressive peers in an attempt to con- struct a program classification scheme based on the masculine role concept portrayed in each program. Children viewed (in either color or blackend-white format) a color television program which had been edited into either "high-violence" or "lowviolence" versions. Post-viewing measures tested the child's recall of central and peri- pheral details and related this recell to the color/violence variations. A methodological note on the research design employed in a study by Lefkowitz, Eron, Walder, 8 Huesmann bee item #30). As part of a longitudinal study of childhood aggression, the investigators H queried the child and/or his parents about his television viewing patterns (e.g. program preferences). Cross-laggad correlations between television t? viewing at age three and adolescent aggressiveness at age 19 were obtained : to provide causal inferences regarding television's role in the development of aggressive behevior. 9 g s Dascriotion Author and Title Experiment I Experiment II Experiment III Experiment IV 32. Liibrt Some Relationships Betwen Viewing Violence and Behaving Aggressively 33. Liebert & Baron Short-Term Effects of Televised Aggression on Children's Aggres- siw Behavior 271 children 40 kindergarten 54 third 56 sixth 51 ninth 70 twelfth 132 children 62 preschool 40 fifth 30 twelfth 160 children 51 fourth 56 sewnth 53 tenth 349 children Bg third 138 sixth 112 tenth 136 children (66 boys 8 88 girls) (65.66 yeeroldsj (71, B-B year-oldsj Subsequent to viewing a television program which contained a number of violent acts each child wes asked to evaluate the motivations and consequences surrounding each depicted act of violence. The child's understanding of these characteristics of violent act was then assessed in terms of the child's willingness to engage in aggressive behavior. Each child viewed a television program which was edited to provide one of four combinations of motivations/consequences for the portrayed violent acts: goobgo~& good-bed, bad-good, and bad-bad. Post-viewing maasures were similar to the prior study. Children viewad one of two versions of a movie in which the justifications for aggmssion had been edited to provide for an "aggmssion-less justified" wrsion. Post-viewing measures of aggressive behavior were similar to those employed in the first experiment. The temporal separation of the motivations for an aggressive act end conse- quences accruing to the aggressor on the child's part-viewing aggressive behavior, was explored in this present study. Measures of aggressive behavior ware similar to previous studies. A raview of currant research on television's role in the imitation and/or dis- inhibition of aggressive behavior (with en additional raport: Strauss 81 Poulos, "Television and Social Leerning: A summary of the Experimental Effects of Observing Filmed Aggression"). In this study the childuia~r's willingness to engage in interpersonal aggression was assessed subsequent to viewing either aggressive or neutral television programming. Author and Title Subjects 34. Liebert, Davidson, & Sob01 Catharsis of Aggression Among Institutionalized Boys: Further Comments 35. Liebert, Sobol, & Davidson Catharsis of Aggression Among Institutionalized Boys: Fact or Artifect? 36. LoSciuto A National Inventory of Television Viewing Behavior 37. Lyle Television in Day-to-Day Life: Patterns of Use 38. Lyle & Hoffman Children's Use of Television and Other Media 39. Lyle & Hoffman Explorations in patterns of television viewing by preschool children 40. McIntyre & Teevan Television and Deviant Behavior 252 families 1682 children 300 first 793677,6th 468-50s. 10th 159 children 40 3 yearolds 82 4 yeer-olds 35 5 yearolds 1 6 year-bid 2270 junior and senior hi&r school students Description A comment on a reply to a critique of the catharsis thesis (see items 14, 15 and 35). A commentary on a study of the role of catharsis in evaluating the effects of viewing telwised violent, (see items 14,15 and 341. A nation-wide sample of American families were interviewed concerning various aspects of television viewing such es; why people watch television, what they learn from programs, extent of viewing, and program preferences. A review of current research in this program, on the role of television in some aspects of daily life. E Children were interviewed about the role television plays in their daily life (e.g. extent and duration of viewing, program preferences, attitudes toward television, use of other forms of mass media). In eddition, the mbthers of first graders were also interviewed concerning their perceptions of the role of 7 television in their child's daily life. z A selected sample of Caucasian, Negro and Mexican-American preschool boys H and girls were intewiewed concerning their television viewing (e.g. program preferences, extent of viewing recognition of television characters). In addition 5 mothers were interviewed concerning their child's television viewing patterns 2: and perceived extent of learning from television. g, Questionnaire responses wem used to provide an estimate of the relationship s betvmen television viewing patterns (e.g. program praferenossj and self-reported aggressive and delinquent behwior. 5 5 Author and Title Subjects 41. McLeod, Atkin, & Chaffee 648 students Adolescent, Parents and Maryland sample Television Use: 229 7th Gradars Self-Report and Other 244 10th Graders Report Measures from the Wisconsin sample Wisconsin Sample 56 7th Graders 83 10th Graders 42.. McLeod, Atkin & Chaffee Adolescent, Parents and Television Use: Adolescent Self-Report Measures from Maryland and Wisconsin Sample 43. Murray 27,5-6 year-old boys Television in Inner-City Homes: Viewing Behavior of Young Boys 44. Neale Comment on: Television Violence and Child Aggres- don: A Follow-up Study A methodological note on the Lefkowitz, Eron, Walder, & Huesmann study bee item #30). 45. Rabinovich, MacLean, 57 6th grade children This study wes designed to assess changes in the child's perception of violence Markham, & Talbott 24 girls as a result of viewing televised violence. Children viewed either an aggressive Children's Violence Per- 33 boys or nonaggressive television program and were then presented with a discrimina- ception as a Function tion task (i.e. identifying a tachistoscopically presented slide as either "violent" of Television Violence or "nonviolent"). 46. Robinson Television's Impact on Everyday Life: Soma Cross-National Evidence This study was focussed on the respondent's allocation of tirna ("timebudgets") to various activities (e.g. work, child care, leisure, mass media use) in his daily life. Time budgsts were sampled in 15 cities in 11 countries. 5 Description Self-report, peer, and "other" rated indicies of aggressive behwior were related ? to various aspects of the adolescent's pattern of telwision use (e.g. extent of Ei viewing, program preferences, cognitiw reactions to televised violence). x m See item #41: A comparison between adolescent television viewing and self- reported aggressive or delinquent behavior. Observation of in-home television viewing, parent-child interviews, diary records of ona week's television viewing, and measures of cognitive and social development were used to provide a description of the role television plays in the daily lives of a selected sample of young.boys (with an additional report: Furfey, "First Graders Watching Television). Author and Title 47. Robinson Toward Defining the Functions of Television 4s. Robinson & Bachman Television Viewing Habits and Aggression 49. Robinson & Israel Demographic Charac- teristics of Viewers of Television Violence and News Programs 50. Shinar Structure and Content of Television Broadcast- ing in Israel 51. Stein & Friedrich Television Content and Young Children's Behavior 52. Stevenson Television and the Behavior of Preschool Children Subjects Description A review of current research on the role of television in relation to other daily activities. 1559, 19 year-old males As part of a nation-wide survey of the changing characteristics of youth, respondents were asked to indicate the extent of their television viewing, program preferences, and the locus of "greatest-learning-about-life"-television vs. school. These findings were then related to the respondents self-reported incidence of aggressive and delinquent behaviors. 6,834 adults Information on preferences and viewing patterns of a nation-wide survey of adult television viewers were related to various demographic characteristics (e.g. age, education, income and sex). A review of television broadcasting policies in Israel. 97, 3% to 5% year-olds Preschool children were exposed to either an "aggressive, neutral, or prosocial" 52 boys television diet and then observed during the course of their daily interaction m 45 girls with other children in their classroom. The observations were conducted over < a nine-week period including three-week baseline, four-week controlled viewing, r-2 and two-week follow-up periods. Changes (over baseline1 in either aggressive or $! prosocial behaviors were used to provide a measure of the impact of television programming. 5 A discussion of research findings on the impact of television in early childhood 4: and suggestions for future research. g e z 0 5 Author and Title Subjects 53. Tannenbaum Studies in Film-and TV- Mediated Arousal and Aggression 54. Wackman, Reale & Ward Racial Differences in Responses to Advertis- ing Among Adolescents 55. Ward Effects of Television Advertising on Children and Adolescents 56. Ward, Levinson & Wackman Children's Attention to Television Advertising 57. Ward, Reale, & Levison Children's Perceptions, Explanations, and Judgments of Television Advertising: A further Exploration 58. Ward & Robertson Adolescent Attitudes Toward Television Advertising 59. Ward & Wackman Family and Media Influences on Adoles- cent Consumer Learning 1149,8th-12th graders 1049 whites 100 blacks 134 mothers of 5-12 year old children 1094,8th-12th graders 1094,8th-12th graders Description A review of research and theory on mediating factors (e.g. emotional arousal) g in the relationships between viewing televised violence and subsequent aggres- E sive behavior. x m `This study was focused on a comparison of the responses of black and white adolescents to television advertising in terms of their favorite ads, extent of "learning consumer roles", and reasons offered for viewing commercials. A review and discussion of research, in the current program, on the impact of television advertising. interviews were conducted with the mothers of young children in order to determine the short-term consequences of watching television advertising. An elaboration of the Blatt, Spencer, & Ward study (see item #3.) This study was designed to relate adolescent's attitudes toward television adver- tising to demographic characteristics, family communication patterns, and television use. This survey assessed the adolescent's "consumer skills" (i.e., recall of advertising content, attitudes toward commercials, materialistic attitudes, and buying behavior) and related these skills to various demographic character. Author and Title 60. Ward & Wackman Television Advertising and Intra-Family Influence: Children's Purchase Influence Attempts and Parental Yielding Subjects 109 mothers of 5-12 year-old children Descriotion Interviewers asked the mothers of young children to describe the "effects of television advertising" in terms of the frequency and intensity of their child's "requests" for advertised products. Appendix C: Experiments on Children's Imitation of Aggressive Behavior Bandura, A., and Huston, A.C. Identification as a process of incidental acquisition of imitative responses. Journal of Personality and Social Psychology, 1(6):589-595, 1965. Bandura. A., Grusec, J. E., and Menlove, F.L. Observational learning as a function of symbolization and incentive set. Child Development, 37:499-506, 1966. Bandura, A., and Huston, A. C. Identification as a process of incidental learning. Journal of Abnormal and Social Psychology, 63:311-318, 1961. Bandura, A., Ross, D., and Ross, S.A. Transmission of aggression through imitation of aggressive models. Journal of Abnormal and Social Psychology, 63:575-582, 196 1. Bandura, A., Ross, D., and Ross, S.A. Imitation of film-mediated ag- gressive models. Journal of Abnormal and Social Psychology, 66:3- II. 1963. Bandura, A., Ross, D., and Ross, S.A. A comparative test of the status envy, social power, and secondary reinforcement theories of identifi- cation learning. Journal of Abnormal and Social Psychology, 67:527- 534, 1963. Bandura, A., Ross, D., and Ross, S. A. Vicarious reinforcement and imitative learning. Journal of Abnormal and Social Psychology, 67:601-607, 1963. Christy, P. R., Gelfand, D.M., and Hartmann, D.P. Effects of competi- tion-induced frustration on two classes of modeled behavior. Devel- opmental Psychology, 1971, in press. Hanratty, M.A., Liebert, R.M., Morris, L.W., and Fernandez, L.E. Imitation of film-mediated aggression against live and inanimate vic- tims. Proceedings of the American Psychological Association, 457- 458, 1969. 159 160 TELEVISION AND GROWING UP Hicks, D. J. Imitation and retention of film-mediated aggressive peer and adult models. Journal of Personality and Socia/ Psychology, 2:97- 100, 1965. Hicks, D.J. Effects of co-observer's sanctions and adult presence on imitative aggression. Child Development. 39:303-309, 1968. Kniveton. B.H.. and Stephenson, G.M. The effect of pre-experience on imitation of an aggressive film model. British Journal of Social and Clinical Psychology, 9:3 l-36, 1970. Kuhn, D. Z., Madsen, C. H., Jr., and Becker, W. C. Effects of exposure to an aggressive mode] and "frustration" on children's aggressive behavior. Child Development, 38:739-745, 1967. Madsen, C.. Jr. Nurturance and modeling in preschoolers. Child Devel- opment, 39:221-236, 1968. Martin, M.F., Gelfand, D.M., and Hartmann, D.P. Effects of adult and peer observers on children's responses to an aggressive model. De- velopmental Psychology, 1971, in press. Nelson, J.D., Gelfand, D. M., and Hartmann, D. P. Children's aggres- sion following competition and exposure to an aggressive model. Child Development, 40:1085-1097. 1969. Rosekrans, M.A., and Hartup, W.W. Imitative influences of consistent and inconsistent response consequences to a model on aggressive behavior in children. Journal of Personality and Social Psychology, 7:429-434, 1967. Walters, R. H., and Willows, D.C. Imitative behavior of disturbed and nondisturbed children following exposure to aggressive and nonag- gressive models. Child Development. 39:79-89, 1968. Appendix D: Experiments on Disinhibition of Aggressive Behavior CHILDREN Albert, Robert S. The role of the mass media and the effect of aggressive film content upon children's aggressive responses and identification choices. Genetic Psychology Monographs, 55:221-285, 1957. Emery, F. E. Psychological effects of the western film: a study in television viewing. II. The experimental study. Human Relations, 12:215-232, 1959. Feshbach, Seymour, and Singer, Robert D. Television and aggression: An experimental field study. San Francisco: Jossey-Bass, 1971. Foulkes, David, and Rechtschaffen, Allan. Presleep determinants of dream content: effects of two films. Perceptual and Motor Skills, 19(3):983-1005, 1964. Goldstein, Naomi Slutsky. The effect of animated cartoons on hostility in children. New York University, 1956. Djssertation Abstracts, 17:1125, 1957. Hartman, Donald P. Influence of symbolically modeled instrumental aggression and pain cues on aggressive behavior. Journal of Personality and Social Psycho/ogy, 11(3):280-288, 1969. Kuhn, Deanna Zipse, Madsen, Charles H., Jr., and Becher, Wesley C. Effects of exposure to an aggressive model and "frustration" on children's aggressive behavior. Chifd Development, 38(3):739-745, 1967. Larder, Diane L. Effects of aggressive story content on non-verbal play behavior. Psychological Reports, 11: 14, 1962. Lovaas, 0. Ivar. Effect of exposure to symbolic aggression on aggressive behavior. Child Development, 32:37-44, 1961. Maccoby, Eleanor E., Levin, Harry, and Selya, Bruce M. The effects of emotional arousal on the retention of aggressive and nonaggressive movie content. American Psychologist, 10(8):359, 1955. 161 162 TELEVISION AND GROWING UP Maccdby, Eleanor E., Levin, Harry, and Selya, Bruce M. The effects of emotional arousal on the retention of film content: a failure to replicate. Journal of Abnormal and SocialPsychology, 53(3):373-374, 1956. Maccoby, Elearnor E., and Wilson, William Cody. Identification and observational learning from films. Journal of Abnormal and Social Psychology. 55:75-87, 1957. Meyerson, Leonard Jack. The effects of filmed aggression on the aggressive responses of high and low aggressive subjects. University of Iowa, 1966. Dissertation Abstracts, 27,3291-B, 1967. Mussen, Paul, and Rutherford, Eldred. Effects of aggressive cartoons ofi children's aggressive play. Journal of Abnormal and Social Psychology, 62(2):46 l-464, 196 1. Siegel, Alberta Engvall. Film-mediated fantasy aggression and strength of aggressive drive. ChiId Development. 27:365-378, 1956. YOUNG ADULTS Berkowitz, Leonard, Corwin. Ronald, and Heironimus, Mark. Film violence and subsequent aggressive tendencies. Public Opinion Quarterly, 27:217-229, 1963. Berkowiti, Leonard, and Geen, Russell G. Film violence and the cue properties of available targets. Journal of Personality and Social Psychology, 3(5):525-530, 1966. Berkowitz, Leonard, and Geen, Russell G. Stimulus qualities of the target of aggression/ a further study. Journal of Personality and Social Psychology, 3(5):525-530, 1966. Berkowitz, Leonard, and Geen, Russell G. Stimulus qualities of the target of aggression: a fuither study. Journal of Personality and Social Psychology, 5(3):364-368, 1967. Berkowitz, Leonard, and Rawlings, Edna. Effects of film violence on inhibitions against subsequent aggression. Journal of Abnormal and Social Psychology, 66(3):405-4 12, 1963. Bokander, Ingvar, and Lindbom, Kerstin. The effects of aggressive films on minors. Nordisk Psykologi, 19(l): l-56, 1967. Feshbach, Seymour. The drive reducing function of fantasy behavior. Journal of Abnormal and Social Psychology, 60(1):3-l 1, 1955. Feshbach, Seymour. The stimulating versus cathartic effects of a vicarious aggressive activity. Journal of Abnormal and Social Psychology, (63)(2):381-385, 1961. Geen, Russell G. Effects of frustration, attack, and prior training in aggressiveness upon aggressive behavior. Journal of Personality and Social Psychology, 9(4):3 16-321, 1968. APPENDIX D 163 Geen, Russell G., and Berkowitz, Leonard. Name-mediating aggressive cue properties. Journal of Personality, 34:456-465,1966. Geen, Russell G., and Berkowitz, Leonard. Some conditions facilitating the occurrence of aggression after the observation of violence. Journal of Personality, 35:66-676, 1967. Kaufman, Harry, and Feshbach, Seymour. The influence of antiaggressive communications upon the response to provociation. Journal of Personality, 31(3):428-444, 1963. Lefcourt, Herbert M., Barnes, Keith, Parke, Ross, and Schwartz, Fred. Anticipated social censure and aggression-conflict as mediators of response to aggression induction. Journal of Social Psychology, 70:251-263, 1966. Walters, Richard H., and Llewellyn-Thomas, Edward. Enhancement of punitiveness by visual and audiovisual displays. Canadian Journal of Psychology, 17:244-255, 1963. Walters, Richard H., Llewellyn-Thomas, Edward, and Acker, C. William. Enhancement of punitive behavior by audiovisual displays. Science, 136(3519):872-873, 1962. Appendix E: The Interpretation of Correlation Coefficients The Pearson product moment correlation coefficient is an abstract sta- tistic which, under certain restrictive conditions, precisely describes the relationship between two variables. Although the restrictive conditions or "assumptions" underlying the application of the correlation coeffi- cient (normal distributions in both variables, strict linearity of regres- sion, stratified random sampling in one of the variables, and homosce- dasticity or equal variance in the arrays) are seldom if ever met in prac- tice, the correlation coefficient is widely used-albeit with a grain of salt -as a crude indicator of a relationship. Many misunderstandings arise from what appears to be a general tendency to misinterpret or overinterpret correlation coefficients. At certain levels, there can be no mistake in interpretation. A correla- tion coefficient of 1 .O means unequivocally that, as the value of one vari- able increases, the value of the other variable increases proportionately; a correlation coefficient of - 1.0 means that increase in one variable is accompanied by proportionate decrease in the other. A value of 0.0 clearly means that there is no linear relationship between the two varia- bles. But what about the cases where the correlation coefficient is in some middle range, like the .30 relationships which stand out from the mass of trivial relationships reported in these studies? If, indeed, the assump- tions listed above are met, one can still say that, as one variable increas- es in value, the mean value of the other variable increases, although at each level of the first variable, there is considerable variation around the mean of the second variable. Furthermore, if the assumptions are not met (as in many of the correlation coefficients in these studies), such a bland statement of a functional relationship is clearly misleading. Thus, if the requirements for linearity and homoscedasticity are not met, two important pitfalls await the unwary interpreter of correlation coeffi- cients: 165 166 TELEVISION AND GROWING UP (1) The functional relatioriship may exist strongly in one or more parts of the range of the variables, but not in other parts of the range. (2) Frequently, the locus of the relationship is at the very top or very bottom of the range in both variables, so that a relatively small number of outlying cases may produce a relationship which exists nowhere else. Statisticians universally advise users of summary statistic,s to examine the data. In the use of correlation coefficients, such advice calls for examination of bivariate distributions or scatter diagrams. Figure E-l : Linear, homoscedastic Figures E-l through E-4 illustrate, in a highly stylized way, the variety of data configurations that can lead to approximately equal correlation coefficients. In each figure, each dqt represents an individual case; the solid line represents the least-squares regression line. We have not at- tempted to make these figures precise, nor to use real data. Adjustment of scale and frequencies can modify the size of the correlation coeffi- cients. Nevertheless, comparison of the four figures will indicate that similar correlation coefficients can summarize different situations which vary markedly in regard to the actual overall relationship between two variables among a group of individuals. APPENDIXE 167 . .:: .... ..... ...... ....... ........ ......... .......... ........... .t .......... ............. .............. ............... ................ ................. .................. ................... .................... ..................... ...................... ....................... ........................ ......................... .......................... ........................... ............................ Figure E-2: Linear, heteroscedastic Variance accountability The square of the correlation coefficient is legitimately interpreted as the "proportion of variance accounted for." This powerful-sounding accomplishment is perhaps even more widely misapplied and misunder- stood than the correlation coefficient itself. Each of the component vari- ables is characterized by a "variance'`-i.e., an abstract indicator of dispersion of values around the mean of the variable. If certain condi- tions (homoscedasticity and linearity) are met, and if the correlation coefficient is greater than zero, then, for any given value of one of the variables, the associated values of the other variable will cluster more closely around their mean (i.e.. have less variance) than the original var- iance of the second variable. The proportionate reduction in variance thus achieved, is the "variance accounted for." Thus a correlation coef- ficient of .30 would lead to the statement that nine percent of the vari- ance in each variable is accounted for by variation in the other. This phenomenon is sometimes popularly phrased in terms of improvement over chance in the ability to guess at the value of one of the variables, given knowledge of the value of the other. Of course, if the specified 168 TELEVISION AND GROWING UP Figure E-3 : Non-linear, homoscedastic conditions do not apply (as in Figures E-2 through E-4), then the propor- tion of variance accounted for is an average across the range of the two variables and may be higher in certain parts of the range and lower in others. Figure E-4: Non-linear, heteroscedastic Chance and unreliability In dealing with a mass of reported summary statistics, as this commit- tee has tried to do, two opposing kinds of criticism are likely to be heard: (1) With so many correlation coefficients being reported on the rela- tionship of television exposure and aggressive tendencies, some few of APPENDIX E 169 them will turn out to be significant by chance alone. Indeed, the results here reviewed include a distribution of values for correlation coefficients all purporting to be of operational measures of the same underlying vari- ables. The majority of the values are trivially small, but the central tend- ency of the values is clearly positive. En masse, they indicate a small positive relationship between amount of violence viewing and aggres- sive behavior. We have paid particular attention to the few larger corre- lation values, because it is reasonable to assume that some specific qual- ity of the measures used accounts for the stronger relationship found. But, ultimately, only replication will establish whether the stronger rela- tionships derive from such characteristics of the measures or whether they are products of chance. (2) Since the measures used in these relationships are not highly relia- ble (in a psychometric sense), the observed relationships among them are likely to be underestimates of the "true" relationships between the concepts. This, too, is an untestable assertion, since, both for sampling reasons and for reliability reasons, any observed relationship may be either an underestimate or an overestimate of a "true" relationship. In particular, if the "true relationship is 0.0, the probability that an ob- served relationship is an underestimate is exactly equal to the probabili- ty that it is an overestimate. On the other hand, if the "true" relation- ship is positive, then the probability that an observed relationship will, because of unreliability, be an underestimate is larger than the probabili- ty that it will be an overestimate. In the absence of knowledge about the nature of the "true" relationship, any conclusions on this point would be technically unjustified. If we were to assume that the mass of data would lead us to the conclusion that, in truth, there is a low positive rela- tionship between the concepts under consideration, we could say that because of unreliability, the possibility that we are reporting underesti- mates is very slightly higher than the probability that we are reporting overestimates. t ". s. GOVERNMENT PRINTING OFFICE : ,071 120-717/633 DHEW Publication No. HSM 72-9090 Printed 1972 U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE Health Services and Mental Heahh Administration