Revisiting the knowledge gap hypothesis: A meta-analysis of thirty-five years of research

Journalism and Mass Communication Quarterly

Volumn 86, Issue 3, 2009, Pages 513-532

  Hwang, Yoori ^a   Jeong, Se Hoon ^b  

^a UNIVERSITY OF MINNESOTA   (United States)

^b Korea University   (South Korea)

Author keywords

[No Author keywords available]

Indexed keywords

KNOWLEDGE; MASS MEDIA; META-ANALYSIS;

EID: 73849093642     PISSN: 10776990     EISSN: None     Source Type: Journal    
DOI: 10.1177/107769900908600304     Document Type: Review

References (151)

1. See Philip. J. Tichenor, George. A. Donohue, and Clarice N. Olien, "Mass Media Flow and Differential Growth in Knowledge, " Public Opinion Quarterly 34 (summer 1970):159-70.
2. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge, " 159-60.
3. See Kasisomayajula Viswanath and John R. Finnegan Jr., "The Knowledge Gap Hypothesis: Twenty Five Years Later, " in Communication Yearbook 19, ed. Brant R. Burleson (Thousand Oaks, CA: Sage, 1996), 187-227.
4. Cecilie Gaziano, "The Knowledge Gap: An Analytical Review of Media Effects, " Communication Research 10 (October 1983):447-86;
5. Cecilie Gaziano, "Forecast 2000: Widening Knowledge Gaps, " Journalism & Mass Communication Quarterly 74 (summer 1997):237-64;
6. Viswanath and Finnegan, "The Knowledge Gap Hypothesis: Twenty-Five Years Later."
7. Wendy Wood and P. Niels Christensen, "Quantitative Research Synthesis: Examining Study Outcomes over Samples, Settings, and Time, " in The Sage Handbook of Methods in Social Psychology, ed. Carol Sansone, Carolyn C. Morf, and A. T. Panter (Thousand Oaks, CA: Sage, 2004), 335-36.
8. See Gaziano, "The Knowledge Gap: An Analytical Review of Media Effects";
9. Gaziano, "Forecast 2000: Widening Knowledge Gaps" for a review.
10. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge."
11. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge."
12. James B. Lemert, "Do Televised Presidential Debates Help Inform Voters?" Journal of Broadcasting & Electronic Media 37 (winter 1993):83-94.
13. George A. Donohue, Philip J. Tichenor, and Clarice N. Olien, "Mass Media and the Knowledge Gap: A Hypothesis Reconsidered, " Communication Research 2 (January 1975):3-23;
14. Thomas M. Holbrook, "Presidential Campaigns and the Knowledge Gap, " Political Communication 19 (October 2002):437-54.
15. Donohue, Tichenor, and Olien, "Mass Media and the Knowledge Gap: A Hypothesis Reconsidered";
16. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge."
17. For example, see Charles T. Salmon, "The Role of Involvement in Health-Information Acquisition and Processing" (Ph. D. diss., University of Minnesota, 1985).
18. Gaziano, "The Knowledge Gap: An Analytical Review of Media Effects";
19. Viswanath and Finnegan, "The Knowledge Gap Hypothesis: Twenty-Five Years Later."
20. James S. Ettema and F. Gerald Kline, "Deficits, Differences, and Ceilings: Contingent Conditions for Understanding the Knowledge Gap, " Communication Research 4 (April 1977):179-202;
21. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge."
22. Gaziano, "The Knowledge Gap: An Analytical Review of Media Effects";
23. Viswanath and Finnegan, "The Knowledge Gap Hypothesis: Twenty-Five Years Later."
24. Heinz Bonfadelli, "The Internet and Knowledge Gaps: A Theoretical and Empirical Investigation, " European Journal of Communication 17 (March 2002):65-84;
25. Peter Clarke and F. Gerald Kline, "Media Effects Reconsidered: Some New Strategies for Communication Research, " Communication Research 1 (April 1974):224-40;
26. Gaziano, "Forecast 2000: Widening Knowledge Gaps";
27. Viswanath and Finnegan, "The Knowledge Gap Hypothesis: Twenty-Five Years Later."
28. For example, see Richard W. Budd, Malcolm S. MacLean, Jr., and Arthur M. Barnes, "Regularities in the Diffusion of Two Major News Events, " Journalism Quarterly 43 (summer 1966):221-30.
29. For example, see Cecilie Gaziano and Alice M. Horowitz, "Knowledge Gap on Cervical, Colorectal Cancer Exists among U. S. Women, " Newspaper Research Journal 22 (winter 2001):12-27.
30. For example, see Alex S. Edelstein, "Decision-making and Mass Communication: A Conceptual and Methodological Approach to Public Opinion, " in New Models for Communication Research, ed. Peter Clarke (Beverly Hills, CA: Sage Publications, 1973), 81-118.
31. John J. Galloway, "The Analysis and Significance of Communication Effects Gaps, " Communication Research 4 (October 1977):363-86;
32. Gaziano, "Forecast 2000: Widening Knowledge Gaps";
33. Kasisomayajula Viswanath, John R. Finnegan, Jr., James Hertog, Phyllis Pirie, and David M. Murray, "Community Type and the Diffusion of Campaign Information, " Gazette 54 (1, 1994):39-59.
34. Gaziano, "The Knowledge Gap: An Analytical Review of Media Effects";
35. Gaziano, "Forecast 2000: Widening Knowledge Gaps";
36. Viswanath and Finnegan, "The Knowledge Gap Hypothesis: Twenty Five Years Later."
37. For a review of different types of communication gaps, see Bonfadelli, "The Internet and Knowledge Gaps: A Theoretical and Empirical Investigation. "
38. For example, Ran Wei, "From Luxury to Utility: A Longitudinal Analysis of Cell Phone Laggards, " Journalism & Mass Communication Quarterly 78 (winter 2001):702-19, was excluded.
39. For example, Reinhold Horstmann, "Knowledge Gaps Revisited: Secondary Analyses from Germany, " European Journal of Communication 6 (March 1991):77-93, and Lemert, "Do Televised Presidential Debates Help Inform Voters?" were excluded.
40. John E. Hunter and Frank L. Schmidt, Methods of Meta-analysis: Correcting Error and Bias in Research Findings (Thousand Oaks, CA: Sage, 2004);
41. Blair T. Johnson and Alice H. Eagly, "Quantitative Synthesis of Social Psychological Research, " in Handbook of Research Methods in Social and Personality Psychology, ed. Harry T. Reis and Charles M. Judd (New York, NY: Cambridge University Press, 2000), 496-528.
42. pooled meta-analytic research on experimental studies that reported means and standard deviations often use d as the common effect size metric. On the other hand, a meta-analysis of survey studies that reported correlation coefficients (r) often use r as the common effect size metric.
43. See Johnson and Eagly, "Quantitative Synthesis of Social Psychological Research, " for detail.
44. John R. Finnegan, Jr., K. Viswanath, Brenda Rooney, Paul McGovern, Judith Baxter, Patricia Elmer, Karen Graves, James Hertog, Rececca Mullis, Phyllis Pirie, Leslie Trenkner, and John Potter, "Predictors of Knowledge about Eating in a Rural Midwestern U. S. City, " Health Education Research 5 (Decemberl990):421-31;
45. Maria E. Grabe, Annie Lang, Shuhua Zhou, and Paul D. Bolls, "Cognitive Access to Negatively Arousing News: An Experimental Investigation of the Knowledge Gap, " Communication Research 27 (February 2000):3-26;
46. Wayne Wanta and William R. Elliott, "Did the 'Magic' Work? Knowledge of HIV/AIDS and the Knowledge Gap Hypothesis, " Journalism & Mass Communication Quarterly 72 (summer 1995):312-21.
47. Budd, MacLean, and Barnes, "Regularities in the Diffusion of Two Major News Events";
48. Paul J. Deutschmann and Wayne A. Danielson, "Diffusion of Knowledge of the Major News Story, " Journalism Quarterly 37 (summer 1960):345-55;
49. Edelstein, "Decision-making and Mass Communication: A Conceptual and Methodological Approach to Public Opinion";
50. Asghar Fathi, "Diffusion of a 'Happy' News Event, " Journalism Quarterly 50 (summer 1973):271-77;
51. Cecilie Gaziano, "Neighborhood Newspapers, Citizen Groups and Public Affairs Knowledge Gaps, " Journalism Quarterly 61 (fall 1984):556-66, 599;
52. Elihu Katz, Hanna Adoni, and Pnina Parness, "Remembering the News: What the Picture Adds to Recall, " Journalism Quarterly 54 (summer 1977):231-39;
53. David W. Moore, "Political Campaigns and the Knowledge-gap Hypothesis, " Public Opinion Quarterly 51 (summer 1987) " 186-200;
54. Charles T. Salmon, Karen Wooten, Eileen Gentry, Galen E. Cole, and Fred Kroger, "AIDS Knowledge Gaps: Results from the First Decade of the Epidemic and Implications for Future Public Information Efforts, " Journal of Health Communication 1 (April 1996):141-55;
55. John Stauffer, Richard Frost, and William Rybolt, "The Attention Factor in Recalling Network Television News, " Journal of Communication 33 (winter 1983):29-37;
56. Viswanath et al., "Community Type and the Diffusion of Campaign Information";
57. Serena Wade and Wilbur L. Schramm, "The Mass Media as Sources of Public Affairs, Science and Health Knowledge, " Public Opinion Quarterly 33 (summer 1969):197-209.
58. Gaziano and Horowitz, "Knowledge Gap on Cervical, Colorectal Cancer Exists among U. S. Women";
59. Cecilie Gaziano and Joann O'Leary, "Childbirth and Infant Development Knowledge Gaps in Interpersonal Settings, " Journal of Health Communication 3 (January 1998):29-51;
60. Alice M. Horowitz, "Gaps in Knowledge among Women about Gynecological and Colorectal Cancer Screening Procedures" (Ph. D. diss., University of Maryland, 1992);
61. Teresa Mastin, "Employees' Understanding of Employer-sponsored Retirement Plans: A Knowledge Gap Perspective, " Public Relations Review 24 (winter 1998):521-34;
62. Ann-Marie Nazzaro, "The Knowledge Gap Hypothesis and Salience in the Context of Health Maintenance Organizations and the Elderly" (Ph. D. diss., University of Pennsylvania, 1989);
63. Wai H. Pun, "News Infographics and Knowledge Gap" (M. A. thesis, University of Texas at Austin, 1991).
64. 2 Lipsey and Wilson's Excel macro was used to compute some effect sizes that could not be calculated by Comprehensive Meta-Analysis. For more information
65. see Mark W. Lipsey and David B. Wilson, Practical Metaanalysis (Thousand Oaks, CA: Sage, 2001).
66. We chose to compare the highest and lowest SES group because (a) the original hypothesis concerns the difference between high and low SES groups, and (b) previous research often compared the highest and lowest groups when there are more than two groups (e.g., Gaziano, "Neighborhood Newspapers, Citizen Groups and Public Affairs Knowledge Gaps"). It is worthwhile to note that there often was a greater difference between the lowest and medium SES group, while the knowledge level of the highest SES group was similar or even lower than that of the medium SES group. Thus, choosing the highest and lowest SES group is unlikely to overestimate the effect size of the knowledge gap.
67. Hunter and Schmidt, Methods of Meta-analysis: Correcting Error and Bias in Research Findings.
68. Studies included in this meta-analysis were as follows: Michelle C. Berry, "What Matters Most in Predicting Health Knowledge-Media Use, Group Participation, Socioeconomic Status, or Race Variables?" (master's thesis, Cornell University, 1992);
69. Budd, MacLean, and Barnes, "Regularities in the Diffusion of Two Major News Events";
70. Fiona Chew and Sushma Palmer, "Interest, the Knowledge Gap, and Television Programming, " Journal of Broadcasting & Electronic Media 38 (summer 1994):271-87;
71. Yunhee Choe, "Situational Variables in Perception and Information Regarding Public Affairs" (Ph. D. diss., Ohio University, 1986);
72. Peter Clark and Eric Fredin, "Newspapers, Television, and Political Reasoning, " Public Opinion Quarterly 42 (summer 1978):143-60;
73. Deutschmann and Danielson, "Diffusion of Knowledge of the Major News Story";
74. Donohue, Tichenor, and Olien, "Mass Media and the Knowledge Gap: A Hypothesis Reconsidered";
75. Edelstein, "Decisionmaking and Mass Communication: A Conceptual and Methodological Approach to Public Opinion";
76. William P. Eveland, Jr. and Dietram A. Scheufele, "Connecting News Media Use with Gaps in Knowledge and Participation, " Political Communication 17 0anuary 2000):215-37;
77. Fathi, "Diffusion of a 'Happy' News Event";
78. Finnegan et al., "Predictors of Knowledge about Eating in a Rural Midwestern U. S. City";
79. Oscar H. Gandy, Jr. and Mohamed E. Waylly, "The Knowledge Gap and Foreign Affairs: The Palestinian-Israeli Conflict, " Journalism Quarterly 62 (winter 1985):777-83;
80. Gaziano, "Neighborhood Newspapers, Citizen Groups and Public Affairs Knowledge Gaps";
81. Gaziano and Horowitz, "Knowledge Gap on Cervical, Colorectal Cancer Exists among U. S. Women";
82. Gaziano and O'Leary, "Childbirth and Infant Development Knowledge Gaps in Interpersonal Settings";
83. B. K. L. Genova and Bradley S. Greenberg, "Interests in News and the Knowledge Gap, " Public Opinion Quarterly 43 (spring 1979):79-91;
84. Grabe et al., "Cognitive Access to Negatively Arousing News: An Experimental Investigation of the Knowledge Gap";
85. Horowitz, "Gaps in Knowledge among Women about Gynecological and Colorectal Cancer Screening Procedures";
86. Leeann Kahlor, Sharon Dunwoody, and Robert J. Griffin, "Predicting Knowledge Complexity in the Wake of an Environmental Risk, " Science Communication 26 (September 2004):5-30;
87. Katz, Adoni, and Parness, "Remembering the News: What the Picture Adds to Recall";
88. Nojin Kwak, "Revisiting the Knowledge Gap Hypothesis: Education, Motivation, and Media Use, " Communication Research 26 (August 1999):385-413;
89. Nicholas P. Lovrich, Jr. and John C. Pierce, "Knowledge Gap Phenomena: Effect of Situation-Specific and Transsituational Factors, " Communication Research 11 (July 1984):415-34;
90. Mastin, "Employees' Understanding of Employersponsored Retirement Plans: A Knowledge Gap Perspective";
91. John T. McNelly and Julio R. Molina, "Communication, Stratification and International Affairs Information in a Developing Urban Society, " Journalism Quarterly 49 (summer 1972):316-26, 339;
92. John T. McNelly, Ramona R. Rush, and Michael E. Bishop, "Cosmopolitan Media Usage in the Diffusion of International News, " Journalism Quarterly 45 (summer 1968):329-32, 339;
93. Moore, "Political Campaigns and the Knowledge-gap Hypothesis";
94. Yuko M. Mulugetta, "Knowledge Gap Hypothesis and Media Preference" (Ph. D. diss., University of Wisconsin, 1986);
95. Nazzaro, "The Knowledge Gap Hypothesis and Salience in the Context of Health Maintenance Organizations and the Elderly";
96. Pun, "News Infographics and Knowledge Gap";
97. John P. Robinson and Mark R. Levy, The Main Source: Learning from Television News (Beverly Hills, CA: Sage, 1986);
98. Prodipto Roy, Frederick B. Waisanen, and Everett M. Rogers, The Impact of Communication on Rural Development: An Investigation in Costa Rica and India (Paris: UNESCO, 1969);
99. Salmon, "The Role of Involvement in Health-Information Acquisition and Processing";
100. Salmon et al., "AIDS Knowledge Gaps: Results from the First Decade of the Epidemic and Implications for Future Public Information Efforts";
101. Elaine B. Sharp, "Consequences of Local Government Under the Klieg Lights, " Communication Research 11 (October 1984):497-517;
102. Prakash M. Shingi, Gurinder Kaur and Ravi P. Rai, Television and Knowledge-Gap Hypothesis (Ahmedabad, India: Indian Institute of Management, 1982);
103. Leslie B. Snyder, "The Impact of the Surgeon General's Understanding AIDS Pamphlet in Connecticut, " Health Communication 3 (1, 1991):37-57;
104. John Stauffer, Richard Frost and William Rybolt, "Recall and Comprehension of Radio News in Kenya, " Journalism Quarterly 57 (winter 1980):612-17;
105. Stauffer, Frost, and Rybolt, "The Attention Factor in Recalling Network Television News";
106. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge";
107. Philip J. Tichenor, Clarice N. Olien, and George A. Donohue, "Effect of Use of Metro Dailies on Knowledge Gap in Small Towns, " Journalism Quarterly 64 (summer/fall 1987):329-36;
108. Viswanath et al., "Community Type and the Diffusion of Campaign Information";
109. Kasisomayajula Viswanath, Gerald M. Kosicki, Eric S. Fredin, and Eunkyung Park, "Local Community Ties, Communityboundedness, and Local Public Affairs Knowledge Gaps, " Communication Research 27 (February 2000):27-50;
110. Wade and Schramm, "The Mass Media as Sources of Public Affairs, Science and Health Knowledge";
111. Wanta and Elliott, "Did the 'Magic' Work? Knowledge of HIV/AIDS and the Knowledge Gap Hypothesis";
112. Mieneke W. H. Weenig and Cees J. H. Midden, "Mass-media Information Campaigns and Knowledge-gap Effects, " Journal of Applied Social Psychology 27 (11, 1997):945-58;
113. Suzanne R. Yows, Charles T. Salmon, Robert P. Hawkins, and Richard R. Love, "Motivational and Structural Factors in Predicting Different Kinds of Cancer Knowledge, " American Behavioral Scientist 34 (July/August 1991):727-41.
114. Studies included in the analysis are as follows: Chew and Palmer, "Interest, the Knowledge Gap, and Television Programming";
115. Gaziano and O'Leary, "Childbirth and Infant Development Knowledge Gaps in Interpersonal Settings";
116. Genova and Greenberg, "Interests in News and the Knowledge Gap";
117. Moore, "Political Campaigns and the Knowledgegap Hypothesis";
118. Mulugetta, "Knowledge Gap Hypothesis and Media Preference";
119. Salmon, "The Role of Involvement in Health-Information Acquisition and Processing";
120. Salmon et al., "AIDS Knowledge Gaps: Results from the First Decade of the Epidemic and Implications for Future Public Information Efforts";
121. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge";
122. Viswanath et al., "Community Type and the Diffusion of Campaign Information";
123. Wanta and Elliott, "Did the 'Magic' Work? Knowledge of HIV/AIDS and the Knowledge Gap Hypothesis."
124. Q-test is a method of comparing differences in mean effect sizes between groups (e.g., Time 1 vs. Time 2). A Q-test is analogous to the ANOVA test in that it estimates the variability between the group means (Qbetween) relative to the variability within the group means (Qwithin). A significant Q-statistic indicates that the difference between two mean effect sizes is significant. For example, a significant Q-statistic would suggest that the difference in effect sizes between two time points is significant. For more information
125. see Larry V. Hedges and Ingram Olkin, Statistical Methods for Meta-analysis (New York: Academic Press, 1985);
126. Lipsey and Wilson, Practical Meta-analysis.
127. Studies included in the analysis were Chew and Palmer, "Interest, the Knowledge Gap, and Television Programming";
128. Gaziano and O'Leary, "Childbirth and Infant Development Knowledge Gaps in Interpersonal Settings";
129. Mulugetta, "Knowledge Gap Hypothesis and Media Preference."
130. The following studies were included in the analyses: Budd, MacLean, and Barnes, "Regularities in the Diffusion of Two Major News Events";
131. Donohue, Tichenor, and Olien, "Mass Media and the Knowledge Gap: A Hypothesis Reconsidered";
132. Gaziano, "Neighborhood Newspapers, Citizen Groups, and Public Affairs Knowledge Gaps";
133. Gaziano and Horowitz, "Knowledge Gap on Cervical, Colorectal Cancer Exists among U. S. Women";
134. Gaziano and O'Leary, "Childbirth and Infant Development Knowledge Gaps in Interpersonal Settings";
135. Genova and Greenberg, "Interests in News and the Knowledge Gap";
136. Salmon, "The Role of Involvement in Health-Information Acquisition and Processing";
137. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge.
138. For example, see Budd, MacLean, and Barnes, "Regularities in the Diffusion of Two Major News Events."
139. For example, see Clark and Fredin, "Newspapers, Television, and Political Reasoning."
140. Roy, Waisanen, and Rogers, The Impact of Communication on Rural Development: An Investigation in Costa Rica and India.
141. The numbers in parentheses are the number of individuals used for effect size calculation. Because this meta-analysis calculated knowledge gap effect size by comparing the highest SES group and the lowest SES group when a study reported the means and standard deviations of the knowledge scores among multiple SES groups, medium SES group respondents were not included for effect size calculation.
142. Gaziano, "The Knowledge Gap: An Analytical Review of Media Effects";
143. Gaziano, "Forecast 2000: Widening Knowledge Gaps."
144. K. Viswanath, Nancy Breen, Helen Meissner, Richard P. Moser, Braford Hesses, Whitney R. Steele, and William Rakowski, "Cancer Knowledge and Disparities in the Information Age, " Journal of Health Communication 11 (S1, 2006):1-17.
145. Jaeho Cho and Douglas M. McLeod, "Structural Antecedents to Knowledge and Participation: Extending the Knowledge Gap Concept to Participation, " Journal of Communication 57 (June 2007):205-28.
146. Emanuel Gaziano and Cecilie Gaziano, "Social Control, Social Change and the Knowledge Gap Hypothesis, " in Mass Media, Social Control, and Social Change: A Macrosocial Perspective, ed. David Demers and K. Viswanath (Ames: Iowa State University Press, 1999), 117-36;
147. Tichenor, Donohue, and Olien, "Mass Media Flow and Differential Growth in Knowledge."
148. We would like to thank an anonymous reviewer for raising this point.
149. Gaziano, "Forecast 2000: Widening Knowledge Gaps";
150. Viswanath and Finnegan, "The Knowledge Gap Hypothesis: Twenty-Five Years Later."
151. Hunter and Schmidt, Methods of Meta-analysis: Correcting Error and Bias in Research Findings.