On the News Stand: A Meta-Analysis on the Effect of Pretrial Publicity. Poster presented at the annual meeting of the Association for Psychological Science, 2010. Received Student Research Award.

1. On the News Stand: A Meta-Analysis of the Effect of Pretrial Publicity on Guilt
Sara Marie House
Loyola University Chicago
Introduction Methods
Results of Pretrial Effect Sizes Exploratory Analyses of Posttrial Effect Sizes
Remedies. Finally, exploratory analyses were performed on remedies. Though none of the remedy
Inclusion/Exclusion Criteria
Pretrial publicity (PTP) refers to any news information appearing before a case has gone to trial. It is a 37 independent effect sizes, with a total N of 7,629 were used. Fixed-effects analysis of the effect sizes yielded an average r̅ variables showed significant effects in the meta-regression, this analysis did not allow the testing of what
cause for concern because it can be biasing to potential jurors. The courts use a variety of remedies to Any study providing data on a statistical relationship between pretrial publicity (displayed through a mass = 0.301, SE = 0.011, Z = 28.47, p < 0.0001. The analyses revealed that there was, as expected, substantial variation in effect Strength of evidence. Though the 95% confidence Bruschke and Loges (2004) call the cumulative remedy hypothesis, which states that, while a single
Strength of Evidence k N r SE 95% CI
counteract the possible effects of pretrial publicity: media source) and at least one measure of guilt, which could be either dichotomous (not guilty/guilty) or sizes, Q (df 36) = 457.804, p < 0.0001, I2 (percentage of variance not attributable to sampling error) = 92.14%. Therefore, intervals of weak and strong do overlap, the 90% remedy may show no significant effect, the effect of PTP may be reduced through use of a combination of
continuous, was considered for meta-analysis. Adequate information about sample characteristics and how random effects analyses were used: Weak 26 2977 0.086* 0.031 0.011, 0.159 confidence intervals do not, meaning that these two values
• Continuance – wait for a period of time before beginning the trial remedies. Average effect sizes were computed based on the number of remedies used (ranging from 0 to
• Extended voir dire – ask more questions of potential jurors the sample was obtained needed to be provided. can be considered significantly different at the 0.10 level. 4) as well as by combination of remedies used.
Analyses revealed no significant moderators (see Meta- Moderate 37 6162 0.213* 0.031 0.154, 0.270
• Admonition – tell jurors to disregard anything learned before trial Q df p As expected, studies using moderate case evidence had
Studies examining the effect of positive PTP were not included in the present meta-analysis. Regression Results table). The random-effects component,
Strong 4 1406 0.159 0.089 -0.017, 0.325 the largest effect.
• Change of venire – use potential jurors from another jurisdiction Effect of moderators 3.89 9 0.92 however, explained a significant proportion of variance,. The Remedies k N r SE 95% CI
Studies could take place in the United States, Canada, or Great Britain. Due to these criteria, all studies
• Change of venue – move the trial to another jurisdiction grand mean effect size was r = 0.323, SE = 0.042, Z = 7.96, p < None Overall 12 1962 0.159* 0.055 0.054, 0.260
obtained were in English. Variance after moderators 22.63 27 0.70
Unfortunately, there is not a lot of evidence in research that these remedies actually work. Many people 0.001, 95% CI = 0.245, 0.397, 95% PI = -0.223, 0.893, Crime. Crime also appears to Crime k N r SE 95% CI 1 remedy
associated with the justice system, however, have lamented that current research findings do not provide Moderators Overall variance after random-effects 26.52 36 0.88
fail-safe N = 114. Admonition 10 1101 0.152* 0.063 0.034, 0.266
have a strong influence on effect Civil 3 322 0.238* 0.118 0.013, 0.440
information on how pretrial publicity can influence jury verdicts (Chesterman, 1997; Jones, 1991). • Source of sample Delay 7 964 0.106 0.077 -0.040, 0.248
sizes. Specifically, non-violent Homicide 13 1900 0.290* 0.055 0.193, 0.381
Furthermore, even among pretrial publicity researchers, this issue is a matter of debate. The fact that there Deliberation 3 464 0.273* 0.105 0.073, 0.452
• Method of assignment to groups Results of Posttrial Effect Sizes crimes and crimes involving Other Non-Violent 7 1047 0.083 0.071 -0.052, 0.215
is so much variation in not only findings but methodology only fuels this debate further. The current study Instructions 6 1187 0.157* 0.077 0.011, 0.296
• Information contained in the PTP 67 independent effect sizes, with a total N of 10,545 were used. Fixed-effects analysis of the effect sizes yielded an average r sexual assault produce smaller Other Violent 16 2943 0.188* 0.045 0.098, 0.275
is one attempt to discover how and when pretrial publicity can bias verdicts, and to answer questions on Overall 26 3716 0.142* 0.032 0.070, 0.214
• Type of trial – Criminal, Civil = 0.163, SE = 0.009, Z = 17.47, p < 0.0001. Once again, the analyses revealed that there was substantial variation in effect effect sizes. There are two
Sex Offense 9 1349 0.078 0.063 -0.048, 0.201 2 remedies
whether PTP has an effect posttrial, when it has an effect, and whether remedies work. possible explanations for the
• Crime(s) – Homicide, sexual assault, other violent, other nonviolent sizes, Q (df 66) = 378.423, p < 0.0001, I2 = 82.29%. Q df p Admonition + Delay 8 1160 0.169* 0.063 0.043, 0.291
Combination of Homicide and Other Crimes 16 2948 0.105* 0.045 0.015, 0.195
Past Meta-Analysis • Type of media Analyses revealed significant moderators (see Meta-Regression smaller effect sizs in sexual Admonition + Deliberation 1 80 0.139 0.197 -0.244, 0.484
Effect of moderators 25.16 17 0.006 Unknown Combination 4 202 0.159 0.110 -0.053, 0.357
Results table). The grand mean effect size was r = 0.163, assault cases: 1) PTP publishes Admonition + Instructions 1 202 0.323 0.176 -0.012, 0.593
The most recent, and only published, meta-analysis was performed by Steblay, Besirevic, Fulero, and • Stimuli provided to control group
Variance after moderators 52.36 49 0.35 negative information about the victim, and 2) jurors are unsympathetic to victims of sexual assault. Since sexual Delay + Deliberation
SE = 0.023, Z = 7.14, p < 0.001, 95% CI = 0.118, 0.207, 11 1911 0.166* 0.055 0.054, 0.274
Jimenz-Lorente (1999). They used 44 independent effect sizes with an overall sample size of 5,755. • Remedies
95% PI = -0.222, 0.550, fail-safe N = 178. The posttrial Overall variance after random-effects 87.52 66 0.04 assault was not a significant moderator pretrial, but was posttrial, the evidence points to explanation 2. Delay + Instructions 1 168 -0.035 0.179 -0.369, 0.308
Using a fixed-effects model, Steblay, et al., found a mean effect size of 0.16 (95% CI = -0.13, 0.46) • Strength of evidence – inferred in one of three ways: 1) statement by author of case strength, 2)
Deliberation + Voi r Dire 1 156 0.111 0.182 -0.239, 0.436
conviction rate from pilot group, or 3) conviction rate from control group; less than 35% = weak, 35 to mean effect size was smaller than the pretrial mean effect size. In addition, the 95% confidence intervals do not overlap,
Several moderators were examined: study design, source of sample, time of verdict, delay between Overall 23 3677 0.175* 0.045 0.099, 0.248
69% = moderate, and 70% or higher = strong meaning that these two values can be considered significantly different at the 0.05 level. This confirms the ‘timing Trial presentation method. Finally, since trial
exposure to PTP and verdict, content of PTP, specificity (case-specific versus general), crime, and media Trial Presentation Method k N r SE 95% CI 3 remedies
• Characteristics of participants (gender, race, etc.) – dropped due to missingness hypothesis’. presentation method was found to be a significant
(newspaper, video, or both). Each moderator was analyzed individually; all effect sizes were categorized Brief Summary 15 2234 0.147* 0.045 0.053, 0.239 Admonition + Delay + Deliberation 3 372 0.223 0.122 -0.013, 0.435
• Characteristics of defendant – dropped due to missingness moderator in the regression, average effect sizes were Delay + Deliberation + Voi r Dire 1 68 0.228 0.205 -0.167, 0.559
on the moderator of interest, and average effect sizes were calculated at each level. Z-tests were performed Transcript 11 1603 0.171* 0.055 0.058, .279
• Characteristics of victim – dropped due to missingness Meta-Regression Results computed at each level of presentation. Studies using Overall 4 440 0.248* 0.100 0.058, 0.420
on these averages to test whether they were significantly larger than 0. Unfortunately, this method did not Pretrial Verdict Posttrial Verdict
Audio 7 1145 0.154* 0.071 0.020, 0.283 mock trials or actual trials did not find effect sizes
Variable 4 remedies
allow significance testing on differences between averages, nor did it allow all moderators to be analyzed Coding B 95% CI B 95% CI
Video 25 4234 0.194* 0.032 0.123, 0.263 significantly larger than 0, though these effect sizes are Admonition + Delay + Deliberation + Instructions 1 702 0.246 0.167 -0.076, 0.521
at once. Coding of reports was performed by the study author. Interrater reliability is currently being assessed; no Constant 0.642 -0.174, 1.457 0.013 -0.457, 0.484
Mock Trial 3 144 0.037 0.138 -0.227, 0.295 also based on only a few studies, and could suffer from Admonition + Delay + Deliberation + Voir Dire 1 48 0 0.221 -0.407, 0.407
The current meta-analysis uses 104 effect sizes from 99 independent samples; using weighted least squares information is available at this time. Sample -0.064 -0.194, 0.065 0.006 -0.060, 0.072 Overall 2 750 0.160 0.134 -0.100, 0.397
Actual Trial 6 1185 0.095 0.084 -0.065, 0.250 low power.
multiple regression, multiple moderators were analyzed at once to determine a moderator’s ability to Media Type -0.024 -0.370, 0.322 -0.033 -0.176, 0.111
Statistical Methods
account for unique variance. In addition, the present meta-analysis used random-effects models for all PTP Information -0.067 -0.309, 0.175 0.142 -0.032, 0.316
Effects sizes were computed as Pearson’s r, which were converted using Fisher’s z-transformation prior to
analyses, which Borenstein, et al. (2009) argue tends to be more theoretically justified.
analysis. Results were then converted back to Pearson’s r. Control Group Instructions -0.045 -0.184, 0.094 0.033 -0.013, 0.079 References
Hypotheses
Homicide 0.041 -0.169, 0.250 0.117 -0.013, 0.247
Timing Hypothesis: Pretrial effect sizes will be larger than posttrial effect sizes. If a study had more than one group or more than one measure of the dependent variable, information was Sources used in the meta-analysis are available at: http://saramhouse.bravehost.com/research/ptpmetaanalysis.html
combined to create a single effect size. Variances for these averaged effect sizes were recalculated using Sex Offense -0.003 -0.227, 0.221 -0.178* -0.325, -0.031 Borenstein, M. Hedges, L.V., Higgins, J.P.T., & Rothstein, H.R. (2009). Introduction to meta-analysis. West Sussex, UK: John Wiley & Sons.
Length Hypothesis: Longer trial materials will produce smaller effect sizes. Bruschke, J., & Loges, W.E. (2004). Free press vs. fair trials: Examining publicity’s role in trial outcomes. Mahwah, NJ: Lawrence Erlbaum.
the procedure provided by Borenstein, et al. (2009). Other Violent Crime -.0137 -0.366, 0.093 -0.056 -0.161, 0.049
Amount Hypothesis: Studies using larger amounts of PTP will have larger effect sizes. Chesterman, M. (1997). OJ and the dingo: How media publicity relating to criminal cases tried by jury is dealt with in Australia and America. The American Journal of Comparative Law, 45, 109-147.
Time of measurement was expected to have an effect, so these values were not averaged together and Other Non-Violent Crime 0.023 -0.241, 0.288 -0.103 -0.297, 0.090
Cohn, L.D., & Becker, B.J. (2003). How meta-analysis increases statistical power. Psychological Methods, 8, 243-253. doi:10.1037/1082-989X.8.3.243
Strength Hypothesis: Studies using cases with moderate-strength evidence will produce larger effect sizes pretrial were analyzed separately from those measured posttrial. Delay -0.053 -0.392, 0.286 -0.055 -0.197, 0.086 Cooper, H. (2010). Research synthesis and meta-analysis: A step-by-step approach (4th ed.). Thousand Oaks, CA: SAGE Publications.
than studies using weak or strong evidence.
Strength of evidence - moderate compared to weak and strong 0.198* 0.069, 0.327 Curtner, R., & Kassier, M. (2005). “Not in our town”: Pretrial publicity, presumed prejudice, and change of venue in Alaska: Public opinion surveys as a tool to measure the impact of prejudicial pretrial publicity. Alaska Law Review, 22, 255-
Random-effects models were used in both cases. A random-effects model assumes that there is not one
Sample Hypothesis: Studies using student samples will have similar results as studies using non-student 292.
true effect size, but rather a distribution of effect sizes, based on a variety of study characteristics Strength of evidence - strong compared to weak and moderate 0.034 -0.191, 0.259
samples. Dixon, T.L., & Linz, D. (2002). Television news, prejudicial pretrial publicity, and the depiction of race. Journal of Broadcasting & Electronic Media, 46, 112-136.
(Borenstein, et al., 2009; Cooper, 2010; Lipsey & Wilson, 2001). In order to incorporate multiple Deliberation 0.109 -0.027, 0.246 Hedges, L.V., & Olkin, I. (1985). Statistical methods for meta-analysis. Orlando, FL: Academic Press.
Remedy Hypothesis: Remedies will reduce the effect of PTP on guilt.
moderators into the analyses, weighted least squares regression (also referred to as meta-regression: Trial presentation format -0.030* -0.059, -0.0004 Imrich, D.J., Mullin, C., & Linz, D. (1995). Measuring the extent of prejudicial pretrial publicity in major American newspapers: A content analysis. Journal of Communication, 45, 94-117.
Pretesting Hypothesis: Studies using pretesting will have larger posttrial effect sizes than studies not using Borenstein, et al., 2009) with methods of moments estimation was performed (based on the SPSS macros Jones, R.M. (1991). The latest empirical studies on pretrial publicity, jury bias, and judicial remedies: Not enough to overcome the first amendment right of access to pretrial hearings. American University Law Review, 40, 841-.
pretesting. Judicial admonition 0.057 -0.068, 0.182
provided by Wilson, 2002); the procedure allows for a random intercept but uses fixed slopes. This Lipsey, M.W., & Wilson, D.B. (2001). Practical meta-analysis. Thousand Oaks, CA: SAGE Publications.
Judicial instructions -0.107 -0.256, 0.043 Steblay, N.M., Besirevic, J., Fulero, S.M., & Jimenz-Lorente, B. (1999). The effects of pretrial publicity on juror verdicts: A meta-analytic review. Law and Human Behavior, 23, 219-235. doi:10.1023/A:1022325019080
Other variables were expected to have some effect, but it was unclear from past research and theory how analysis enters moderators first, then computes the random error component based on the remaining
these variables might influence results. These analyses are exploratory. Voir dire -0.061 -0.271, 0.150 Studebaker, C.A., & Penrod, S.D. (2005). Pretrial publicity and its influence on juror decision making. In N. Brewer and K.D. Williams (Eds.), Psychology and law: An empirical perspective (pp. 254-275). New York: Guilford Press.
variance (Lipsey & Wilson, 2001).
Wilson, D.B. (2002). Meta-analysis macros for SAS, SPSS, and Stata. Retrieved September 9, 2009, from http://mason.gmu.edu/~dwilsonb/ma.html
Pretesting -0.080 -0.201, 0.042