Chezy Ofir

Context Effects on Judgment under Uncertainty

This research investigated contextual effects on consumer cue-utilization policies in making judgments under uncertainty. Two studies suggested that the utilization of base and case information varied as a function of the numerical values of the cues and covaried with the changes in the perceived relevance of each cue. The second study showed that individual subjects employed different cue-utilization policies in problems that were formally identical but differed in surface detail. A third study experimentally manipulated two factors that influence perceived relevance and explored their effects on cue utilization. All three studies revealed evidence inconsistent with previous research on underutilization of base-rate information.

I could never have expected it to happen: The reversal of the hindsight bias

Abstract It has been hypothesized and demonstrated in previous research that individuals′ recall of predictive judgments is typically distorted by knowledge of the outcomes of the events predicted. This is attributed to the tendency to downgrade the surprise element associated with the outcomes and the adoption of an “I knew it all along” attitude. The present study identifies the limits of this hypothesis by showing that following the exposure to unexpected events, individuals may react by expressing an “I did not expect this to happen” response and recall predictions opposite to their judgment of the event after its occurrence. In other words, the recall of past judgments may be biased in a direction contrary to rather than consistent with subsequent judgments. Three experiments were conducted in different contexts to test the boundary conditions of the “I knew it all along” hypothesis. The findings in all three experiments suggest that following unexpected and surprising events, recall judgments are biased in a direction opposite to that predicted by the hindsight bias.

Pseudodiagnosticity in judgment under uncertainty

Abstract The study investigates the extent to which the false alarm (i.e., P( D H ) ) is utilized in judgment under uncertainty. The main findings are (1) this cue is utilized by subjects when provided with a numerically low base-rate (i.e., P(H)) and a high hit-rate (i.e., P( D H ) ). Under these conditions the false alarm helps resolve the inconsistency between the implications of these probabilistic cues. (2) The false alarm is ignored by subjects when provided with a numerically high base-rate and a high hit-rate. Under these conditions both latter probabilities are consistent and imply strong support for the focal hypothesis. The false alarm is either not consistent with these cues or redundant and ignored. In addition, three experiments provided evidence regarding base-rate utilization. When comparing conditions (1) and (2) it is demonstrated that the base-rate has a significant effect on judgments. Finally, the experiments provided evidence suggesting that the base-rate is not ignored when the datum is not diagnostic. The results are discussed in relation to the base-rate fallacy, pseudodiagnosticity, and cue consistency.

Multicollinearity in marketing models: Diagnostics and remedial measures

Abstract The problem of multicollinearity in linear models is reviewed. Diagnostic measures for detection, analysis of the effects, and localization of multicollinearity are presented. It is recommended that OLS estimates should not be used without a proper diagnostic. The traditional remedial measures, i.e., omission of variables from the model and principal component regression, are critically discussed along with more recent methods. Ridge regression is presented, and several methods for selecting the biasing parameter in ridge regression are introduced. The procedures are illustrated with data taken from the marketing literature and evaluated for their potential usefulness in handling multicollinearity.

Are Semantic Response Scales Equivalent

Three frequently used response formats -- Likert, semantic-differential and single anchor (Stapel) -- are compared via analysis of covariance structures. The cumulative results based on four data sets provided evidence inconsistent with previous research suggesting that these formats are interchangeable. Consistently across studies, the semantic-differential format is most preferred while in most cases the Stapel format is least preferred.

Quantitative evaluation of persuasive appeals using comparative meta-analysis

ABSTRACT Message appeals are a key component of communication campaigns and an important source of campaign influence. However, research on them is heavily fragmented and it is difficult to generalize findings from the many diverse field studies. Based on a large and unique data set using quantitative and qualitative meta-analyses, this research provides measures of the relative impact of each type of appeal, as well as the major differences among them, and identifies the moderating variables that lead to a better understanding of each. This investigation is based on persuasion research, which provides a framework for understanding the unique characteristics of these advertising appeals. It highlights empirical gaps in the academic literature and acts as a conceptual guide for our research hypotheses. Results reveal weaker effect sizes than those previously reported in the literature and show important differences among appeals that lead to a “hierarchy of appeals.” Specifically, emotional appeals, led by sex and humor, appear to be more effective than fear and rational appeals. The study finds new theoretical and empirical generalizations; some results are counterintuitive and differ from findings generated from single appeal studies. Findings are of theoretical and practical importance.

Advertising Appeals, Moderators, And Impact on Persuasion: A Quantitative Assessment Creates a Hierarchy of Appeals

ABSTRACT This investigation attempts to assess quantitatively past studies on advertising-appeal differences and scale them on a common metric. On the basis of a large and unique dataset using comparative meta-analysis, this study provides measures of the relative impact of seven types of appeals. Meta-regression was used to test whether certain moderators can explain the variability in effect sizes. Results suggest that appeals were not effective equally, and their estimated impact was used to create a hierarchy of appeals. Emotional appeals, led by sex and humor, appeared to be more effective than fear and rational appeals. The most important moderators were media type and year of publication. Among other results, emotional appeals were more effective on television, and emotional appeals were more impactful in more recent studies. The article concludes with implications and discussion, emphasizing the need for more research.

Combining perceptual and economic variables in the demand function

Abstract An item response theory is combined with a main-effect demand function for predicting product sales from perception and price. In the sales function perception is measured on a log interval scale, whereas price is measured on its usual ratio scale. The most important main effect in this function represents a composite of unspecified attributes and other sources of demand variation over competing products. The extraction of this effect serves to unbias the perceptual impact and price elasticity estimates by relieving the underspecification common to demand functions. This main effect also reveals product values that may be studied in subsequent investigations. The present approach of concatenating psychological and economic variables in the same demand equation is illustrated with an analysis of data from a high-tech consumer market.