UNIVERSITY OF CINCINNATI

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1 UNIVERSITY OF CINCINNATI Date: I,, hereby submit this work as part of the requirements for the degree of: in: It is entitled: This work and its defense approved by: Chair:

2 Omission Detection and Inferential Adjustment A dissertation submitted to the Division of Research and Advanced Studies of the University of Cincinnati in partial fulfillment of the requirements for the degree of DOCTORATE OF PHILOSOPHY (PH.D.) in the Department of Marketing of the College of Business 2008 by Bruce E. Pfeiffer B.S., University of Colorado at Boulder M.B.A., Rockhurst University M.S., University of Colorado at Boulder Committee Chair: Frank R. Kardes, Ph.D.

3 ABSTRACT Omission Detection and Inferential Adjustment by Bruce E. Pfeiffer Chair: Frank R. Kardes Omission neglect refers to insensitivity to missing or unknown information. Omission detection occurs once an omission reaches the threshold of awareness. Research in this area has demonstrated that consumers typically rely heavily on the information provided, and neglect omitted information, resulting in inappropriately extreme and confidently held judgments. Three experiments have been designed investigating the underlying processes of how consumers make inferences about omitted attributes. Two plausible explanations are investigated: anchoring and adjustment versus discounting. Adjustment refers to revising or updating an opinion, whereas discounting refers to not using information that is perceived to be non-diagnostic. In Experiment 1, the underlying process is investigated using a point vs. range procedure. Salience of the omitted attribute is manipulated to elicit omission detection and participants are asked to provide either a point estimate or range estimates of the cost of the omitted attribute. Comparisons of the point and range estimates support an anchoring and adjustment explanation, but do not eliminate a discounting explanation. Experiment 2 further investigates the processing differences utilizing a cognitive load manipulation. The results suggest an anchoring and adjustment mechanism for people low in need for cognitive closure and a discounting mechanism for people high in need for cognitive closure. ii

4 Experiment 3 combines the two procedures used in Experiments 1 and 2 to more clearly differentiate the underlying process and investigates additional individual differences. The results suggests that people who are low in need for cognitive closure, people who are low self-monitors, and people who are high maximizers are more likely to utilize an anchoring and adjustment process. Conversely, people who are high in need for cognitive closure, people who are high self-monitors, and people who are low maximizers are more likely to be discounting. These experiments suggest that there are two possible underlying mechanisms for forming inferential judgments and that the type of mechanism used depends on individual trait differences and possibly situational variables. This research adds to the growing body of omission neglect research by helping to explain the underlying mechanisms in the formation of inferential judgments of omitted attribute information once an omission is detected. iii

5 Copyright 2008 Bruce E. Pfeiffer ALL RIGHTS RESERVED iv

6 DEDICATION This work is dedicated to my wife, Lisa, for her love, encouragement, support, tolerance, and patience. v

7 ACKNOWLEDGMENTS This has been a challenging and rewarding process, and I would like to express my gratitude to all those who have helped me along the way. First, I would like to thank my committee chair, Frank Kardes. I cannot express how fortunate I am to have had the opportunity to learn from such a knowledgeable and accomplished researcher. He is a great mentor and friend. Thank you to James Kellaris for his endless supply of advice, wisdom, and wit. His door has always been open to me in times of need. Thank you to David Lundgren for his insightful comments and suggestions. I feel very privileged to have had him serve on my committee. Thank you to the entire marketing faculty at the University of Cincinnati for giving me the opportunity and support to achieve this goal. Specifically, I would like to thank Ph.D. coordinator, David Curry, and department head, Karen Machleit for their excellent advice and guidance throughout my time in the program. I would like to thank Paul Herr for his support, guidance, and friendship. Thank you to Donald Lichtenstein and Dipankar Chakravarti for their continued encouragement. I would like to thank my fellow doctoral students for their friendship through the good times and the suffering. Lastly, I would like to thank my wife, Lisa. Her unconditional belief in me provided me with the courage and determination to achieve this goal. vi

8 TABLE OF CONTENTS CHAPTER ONE Introduction... 1 CHAPTER TWO Literature Review... 4 Omission Neglect and Detection... 4 Inferential Judgments of Omitted Information... 7 Need for Cognitive Closure CHAPTER THREE Experiment Method Results Discussion CHAPTER FOUR Experiment Method Results Discussion CHAPTER FIVE Experiment Method Results Discussion CHAPTER SIX General Discussion References Tables and Figures Appendix A Manipulations and Measures for Experiment Appendix B Manipulations and Measures for Experiment Appendix C Manipulations and Measures for Experiment Appendix D Individual Difference Measures vii

9 TABLES AND FIGURES TABLE 1 TABLE 2 TABLE 3 TABLE 4 TABLE 5 TABLE 6 Average Point Estimates and Rages Provided by Participants in the Salient and Not Salient Conditions (Experiment 1) Inferential Judgment Regressed on Salience and Overall Evaluation (Experiment 2) Average Point Estimates and Rages Provided by Participants in the Salient and Not Salient Conditions (Experiment 3) Inferential Judgment Regressed on Salience and Overall Evaluation (Experiment 3) Inferential Judgment Regressed on Salience and Overall Evaluation (Experiment 3) Inferential Judgment Regressed on Salience and Overall Evaluation (Experiment 3) FIGURE 1 Effect of Salience and Cognitive Load Manipulations for High and Low Need for Cognitive Closure (Experiment 2) viii

10 CHAPTER ONE Introduction Omission neglect refers to insensitivity to missing or unknown information (e.g., attributes, features, properties, qualities, alternatives, options, cues, stimuli, or possibilities) (Kardes and Sanbonmatsu, 2003). In many consumer decision making situations, consumers need to form judgments based on incomplete information. The information may come from different sources (e.g., advertising, promotions, salespeople, the media, independent, word-of-mouth). Advertisers may focus on specific attributes in which they have an advantage over their competition. For instance, some truck ads focus on towing capacity and fully boxed frames while others may focus on passenger comfort, quiet ride, or even fuel economy. Advertisers choose what to present based on how their distinct advantages match their target segment. Similarly, other information sources have their own agendas. Regardless of the source, the information available rarely includes all the attribute information that may be important in forming a judgment. In these cases, consumers usually use whatever information is available, neglecting or even failing to notice what might be missing. Omission detection occurs once an omission reaches the threshold of awareness. For example, Fibersure advertises its product by asking consumers what is missing from their diet. They show various foods with large holes cut out of them, informing consumers, you d be surprised at how much fiber is missing from your diet new Fibersure, it s just what you ve been missing. In these ads, Fibersure, makes a common 1

11 missing attribute salient, and then provides a solution, strengthening the perceived benefits of the product. Not bringing omissions to consumers awareness is, however, much more common, and research has demonstrated that omission detection is surprisingly difficult and the failure to detect omissions is often the norm. Research in this area has demonstrated that consumers typically rely heavily on the information provided and neglect the omitted information, and this results in inappropriately extreme and confidently held judgments (Sanbonmatsu, Kardes, and Sansone, 1991; Sanbonmatsu, Kardes, and Herr, 1992; Sanbonmatsu, Kardes, Posavac, and Houghton, 1997; Sanbonmatsu, Kardes, Houghton, Ho, and Posavac, 2003). In general, people should only form extreme attitudes when they have a large amount of relevant information (Anderson, 1981). Judgments made with limited information should be more conservative. When information is incomplete or limited, moderate judgments will be more accurate than extreme judgments (Griffin and Tversky, 1992). It has been shown that more moderate judgments are made when people are sensitive to the omission of information (Kardes et al., 2006; Sanbonmatsu et al., 1991, 1992, 1997, 2003). Up to now, the omission neglect literature has focused on sensitivity to omissions and how this sensitivity debiases omission neglect through increased omission detection. We are attempting to separate sensitivity to omissions from the effects of adjustment following omission detection. Specifically, we will be looking at the process by which people adjust their inferences about missing information once the omission is detected. 2

12 Three experiments have been designed investigating the underlying processes of how consumers make inferences about omitted attributes. In this research, two plausible explanations are investigated: anchoring and adjustment and discounting. Adjustment refers to revising or updating an opinion, whereas discounting refers to not using information that is perceived to be non-diagnostic. Two different methods available in the literature are used for investigating these underlying mechanisms. 3

13 CHAPTER TWO Literature Review Omission Neglect and Detection As stated earlier, omission neglect refers to insensitivity to missing or unknown information (Kardes and Sanbonmatsu, 2003). Conversely, omission detection refers to sensitivity to missing or unknown information and occurs once an omission reaches the threshold of awareness. Research, however, has demonstrated that omission detection is surprisingly difficult, and the failure to detect omissions often results in inappropriately extreme and confidently held judgments (Sanbonmatsu et al., 1991, 1992, 1997, 2003). For example, Sanbonmatsu et al. (1992) presented participants with attribute information about a camera and asked them to form evaluations. Half the participants received positive information on four attributes, and half received positive information on eight attributes. People should form more favorable evaluations of the camera when they are provided with positive information on eight attributes as opposed to only four. This was, however, only the case for highly knowledgeable people (vs. unknowledgeable or moderately knowledgeable). Only the highly knowledgeable people detected the omission. Unknowledgeable or moderately knowledgeable people formed equally favorable evaluations. These people neglected the omission. Thus, their evaluations based on only four positive attributes were overly extreme given the asymmetry in evaluative information. Research has demonstrated that omission neglect influences all the stages of information processing: perception (Baron and Ritov, 2004; Caputo and Dunning, 2005; Masuda and Nisbett, 2006; Treisman and Souther, 1985), learning (Cronley, Posavac, 4

14 Meyer, Kardes, and Kellaris, 2005; Kardes, Cronley, Kellaris, and Posavac, 2004; Newman, Wolff, and Hearst, 1980), evaluation (Kardes and Gurumurthy, 1992; Kardes and Sanbonmatsu, 1993; Sanbonmatsu et al., 1992, 1997, 2003; Zhang, Kardes, & Cronley, 2002), persuasion (Sanbonmatsu et al., 1997; Tormala and Petty, 2007), and decision making (Kardes et al., 2006; Mantel, Kardes, Isen, and Herr, 2008; Pfeiffer et al., 2008; Sanbonmatsu et al., 1991; Silvera, Kardes, Harvey, Cronley, and Houghton, 2005; Simonson and Kivetz, 2000). It has been shown that more moderate judgments are made when people are sensitive to the omitted information and omissions are detected (Kardes et al., 2006; Sanbonmatsu et al., 1991, 1992, 1997, 2003). Sanbonmatsu, Kardes, and their colleagues have demonstrated that omission detection can be accomplished through manipulating motivation and context. For example, more moderate judgments were made when people were warned that given information was incomplete (Sanbonmatsu et al., 1992), when people had high levels of prior product knowledge (Sanbonmatsu et al., 1991, 1992, 2003), when comparisons between objects were described in various levels of detail (Sanbonmatsu et al., 1997), when comparing objects described by different attributes (Sanbonmatsu et al., 2003), and when people were asked to consider the judgment criteria prior to evaluation (Kardes et al., 2006; Sanbonmatsu et al., 2003;). Further, it has been demonstrated that changes in information format from the initial evaluation to the secondary evaluation can influence sensitivity to missing information and thus the degree of evaluative revision (Muthukrishnan and Ramaswami, 1999). In Experiment 1, Muthukrishnan and Ramaswami (1999) presented participants with positive information about a writing pen in either a comparative or noncomparative 5

15 format. In the noncomparative format, six pieces of attribute information were presented about the target pen. In the comparative format, the target pen was compared to another pen on three attributes. All three attributes favored the target pen. Following an initial evaluation of the target pen, participants were provided with additional information. This time the information was negative. Again, the information was presented in a comparative or noncomparative format. They found that the amount of evaluative change from evaluation one to evaluation two depends on change of format. The greatest evaluative correction occurred when the format changed from a noncomparative to comparative format, or vice versa. In the following experiments, they found that the evaluative correction was mediated by perceived insufficiency of information, demonstrating that the effect was driven by sensitivity to omissions. Up to now, the omission neglect literature has focused on sensitivity to omissions and how this sensitivity debiases omission neglect. We are attempting to separate sensitivity to omissions from the effects of adjustment following omission detection. When consumers become aware that attribute information is missing or are asked to evaluate the importance of an attribute that was not presented, they are forced to make an inferential judgment. Inferential judgments are judgments that go beyond the information that is presented. The question then is how do people go about making these inferential judgments about missing information. In this research, we investigate two plausible explanations: anchoring and adjustment versus discounting. Adjustment refers to revising or updating an opinion, whereas discounting refers to not using information that is perceived to be non-diagnostic. 6

16 One strategy for forming inferences about an unknown is to start with what one does know and then adjust to a reasonable estimation. This is known as the anchoring and adjustment heuristic (Tversky and Kahneman, 1974). In the case of omission neglect, people may anchor on the implications of the presented information and adjust based on the implications of the omitted information. When missing information is made salient, people may engage in effortful processing in order to adjust their inference to a plausible estimate based on the implications of the missing information. Their final inferential evaluation should depend on whether the omissions are detected and on their motivation and ability to adjust away from the initial anchor. Conversely, people may perceive the presented information or their initial evaluation based on this information as non-diagnostic to their inferential judgment of the missing attribute information. As a result, they may discount this information and base their inferential judgment solely on the implications of the omitted information. Inferential Judgments of Omitted Information In most omission neglect studies, people are presented with some but not all of the relevant information on a product or service and asked to evaluate the product or service. As discussed above, the omission neglect literature has shown that people form more moderate evaluations when omissions are detected, implying that the overall evaluations are based on both the implications of the presented information and the implications of the omitted information. When consumers are asked about an attribute that was not presented, they are forced to make an inferential judgment. How do people go about making these inferential judgments about missing information? As stated above, 7

17 we investigate two plausible explanations: anchoring and adjustment versus discounting. Adjustment refers to revising or updating an opinion, whereas discounting refers to not using information that is perceived to be non-diagnostic. In their seminal article Judgment under Uncertainty: Heuristics and Biases, Tversky and Kahneman (1974) identified three heuristics people use in judgment and decision making: representativeness, availability, and anchoring and adjustment. Anchoring and adjustment refers to a specific cognitive process by which people initially focus on an anchor and then adjust toward a final estimate. For example, one group of people were asked whether the percentage of African countries in the United Nations was more or less than 10% and another group was asked whether the percentage was more or less than 65%. Those in the first group estimated that the actual percentage was 25% and those in the second group estimated that the actual percentage was 45%. The initial inquiry (more or less than 10% vs. more or less than 65%) served as an anchor or starting point from which people adjust to form their final estimate (Tversky and Kahneman, 1974). Similarly, Strack and Mussweiler (1997) found that different initial anchors resulted in different estimates of Gandhi s age when he died. If they were asked if he died before or after the age of 140, they provided an average estimate of 67 years old. If they were asked if he died before or after the age of 9, they provided an average estimate of 50 years old. People focused on the initial anchor (140 or 9) and adjusted to a more plausible estimation. Anchoring effects have proven to be very robust and have been demonstrated in many different domains from evaluation of gambles (Carlson, 1990; Chapman and 8

18 Johnson, 1994; Schkade and Johnson, 1989) to judgments of future performance (Switzer and Sniezek, 1991). Further, the anchoring and adjustment heuristic has been very useful in helping to explain a variety of phenomena (e.g., preference reversals, subadditivity, social comparison, egocentric biases, hindsight bias, probability estimates, and trait inference) (Chapman and Johnson, 2002; Epley and Gilovich, 2002; Epley, 2004). Interestingly, it has even been shown that people use an anchor even when the anchor is overly extreme or even implausible (Strack and Mussweiler, 1997), and even when they are explicitly made aware of the anchoring effect (Quattrone, Lawrence, Finkel, 1981; Wilson, Houston, Etling, and Brekke, 1996). Despite the robustness of the effect, not all information makes effective anchors. Research suggests that the most effective anchors are ones that receive sufficient attention and are relevant to the target judgment (Chapman and Johnson, 2002). Epley and Gilovich (2006) demonstrated that adjustment is effortful, and whether people adjust away from the anchor depends on their ability and motivation to seek more accurate estimates. In three studies, they found that people who scored high in need for cognition, people who were sober, and people who were not under cognitive load provided estimates that were further from self-generated anchors than people who were low in need for cognition, people who were intoxicated, and people who were not under cognitive load (respectively). Another explanation for inferential judgment formation is discounting. People may discount the implications of the presented attribute information and base their inferential judgment primarily on the implications of the omitted attribute information. Research has demonstrated that people discount information that they perceive as 9

19 irrelevant or non-diagnostic (e.g., Shul and Burnstein, 1985; Van Overwalle and Labiouse, 2004). Discounting depends on competition between information. The attribution literature has demonstrated that people tend to ignore alternative causes when one of the causes is perceived as primary or acquires a strong causal weight (e.g., Hansen and Hall, 1985; Kruglanski, Schwartz, Maides, and Hamel, 1978; Van Overwalle and Van Rooy 2001). For example, Van Overwalle and Van Rooy (2001) used a variety of novel stories depicting attribution scenarios to demonstrate that more observations of an alternative cause resulted in discounting of the target cause. Trope and Gaunt (2000) demonstrated that when situational information was salient, accessible, or specific, it elicited a strong discounting effect of dispositional inference. Further, in a product evaluation task, Simmons and Lynch (1991) demonstrated that perceived incompleteness of information resulted in less sensitivity and attention to presented information. They used a competitive information context to increase the salience of undescribed attribute information, attenuating of the effects of the described attribute information on product evaluations. The formation of an inferential judgment of a missing attribute may also depend on competition between information. If the implications of the omitted information is salient and viewed as sufficiently relevant, the presented attribute information may be discounted and not used in the inferential judgment. As discussed above, we are investigating two plausible explanations for the underlying process involved in the formation of inferential judgments of missing attribute information: anchoring and adjustment versus discounting. These two processes may depend on how information is encoded. Schul and Burnstein (1985) demonstrated that 10

20 discounting depends on discrete versus integrated encoding. The type of encoding determines the number of associations formed among different pieces of information. Discounting is more likely in cases where the encoding is discrete and less likely when encoding is integrative. Discrete encoding takes place when information can be understood individually. Integrative encoding takes place when the information is combined and considered as a whole. Once information is integrated, all the information is likely to be seen as diagnostic. As a result, an inference about one piece of information is likely to be based on all the information available. If the information is not integrated, however, it may not be as strongly connected. As a result, when asked about one specific attribute, people may be less likely to view the other attribute information as diagnostic. This enables them to discount the other information and based their inference only on the implications of the omitted information. We believe that anchoring and adjustment requires more of an integrated focus requiring a more effortful adjustment. Once the information has been integrated, people are more likely to consider all the information available when forming their inferential judgment about the omitted attribute. This would include all the presented attribute information and their overall evaluation. They anchor on the implications of the presented attribute information and then adjust based on the implications of the omitted attribute information. We believe that discounting is a less involved process. If the information is not integrated, people can focus on any of the pieces of information individually. If the information in encoded discretely, people are able to focus only on the most diagnostic of 11

21 the information. If this is the implications of the omitted attribute information, then they may discount the implication of the presented attribute information and any initial evaluation based on this information, not using it in the formation of their inferential judgment. We use two methods available in the literature for investigating these underlying mechanisms. Epley, Keysar, Van Boven, and Gilovich (2004) use a point versus range procedure to look at the role of anchoring and adjustment in egocentric biases. They found that people estimate the perspective of others by first anchoring on their own perspective and then adjusting. They used ambiguous messages that could either be interpreted as sincere or sarcastic. Participants first read clarifying information about past events making it clear that the message was either sincere or sarcastic. Then participants read the ambiguous message. After the participants had read all the information, they asked half the participants to estimate the number of their peers who would interpret the message (without the clarifying information) as sincere (vs. sarcastic). The other half of the participants were asked to provide a plausible range of this estimate by estimating upper and lower bounds of sincere (vs. sarcastic). For example, all participants were asked to imagine that 100 people were asked to read the (ambiguous) message. The participants in the point condition were then asked to estimate the percentage of these 100 people who thought the message was sincere (vs. sarcastic). The participants in the range condition were asked to provide two estimates, an upper and lower bound of the percentage of people who thought the message was sincere (vs. sarcastic). This betweenparticipant measure was used to ensure that the point generation would not influence the ranges estimations or vice versa. They found that participants point estimates were 12

22 skewed in the direction of the upper or the lower bounds provided by the participants in the range condition. Sarcastic event clarification information resulted in point estimates that were skewed toward the sarcastic end of the range estimates and sincere event clarification information resulted in point estimates that were skewed toward the sincere end of the range estimates. Another method for investigating the underlying process is to place participants under cognitive load (e.g., Chun and Kruglanski, 2006; Epley and Gilovich, 2006). As discussed previously, adjustment is effortful and depends on people s ability and motivation to seek more accurate estimates. Placing people under cognitive load reduces peoples ability to perform effortful cognitive tasks. To manipulate cognitive load, Epley and Gilovich (2006) randomly divided participants into load or no load conditions. Participants in the load condition where asked to memorize an eight-letter string prior to answering questions. Participants in the no load condition did not perform the memorization task. They found that people who were not under cognitive load provided estimates that were further from self-generated anchors on various topics than people who were not under cognitive load, demonstrating that cognitive load interfered with participant ability to adjust away from an anchor. Anchoring and adjustment is a two-step process requiring more cognitive effort than discounting. Since anchoring and adjustment has been shown to depend on ability and motivation, we expect that a cognitive load manipulation should interfere more with the anchoring and adjustment process than the discounting process. The specific use of the point versus range method and the cognitive load method will be described in more detail later in the method sections. 13

23 The Need for Cognitive Closure To aid in investigating the distinction between the two inferential judgment processes, we will also be measuring the need for cognitive closure (Kruglanski and Webster, 1996). The need for cognitive closure refers to a desire to form a definite opinion ( seize ) and to maintain the opinion once it is formed ( freeze ). The need for cognitive closure is conceptualized as a continuum anchored at one end with a high need for closure and at the other with a high need to avoid closure. As need for cognitive closure increases, people s desire to form an opinion increases, and they tend to focus on information that will facilitate closure. As a result, people may form a snap decision or leap to judgment based on incomplete information. Once an opinion is formed, the opinion becomes rigid and people tend to safeguard the opinion and show resistance to change. Conversely, as need for cognitive closure decreases, people s desire to avoid closure increases, and they become more reluctant to commit to a definite opinion. The robustness of the cognitive closure construct has been shown as both a situational variable and as individual difference variable (Webster and Kruglanski, 1994). For example, need for cognitive closure has been shown to increase with time pressure (Cronley, Posavac, Meyer, Kardes, and Kellaris, 2005; Kruglanski and Freund, 1983; Kruglanski and Webster, 1996; Sanbonmatsu and Fazio, 1990; Suri and Monroe, 2003) and fatigue (Kruglanski, 1989, Kruglanski, 1990; Webster, Richter, and Kruglanski, 1996) and to decrease with accountability (Kruglanski, 1989; Kruglanski and Freund, 1983; Tetlock, 1985; Webster, Richter, and Kruglanski, 1996) and enjoyableness of the decision task (Webster, 1993). 14

24 To investigate need for cognitive closure as an individual trait difference, Webster and Kruglanski (1994) developed the Need for Cognitive Closure Scale. The original version is a 42-items scale that has five facets: order, predictability, decisiveness, ambiguity, and close-mindedness. More recent research has divided the scale into two orthogonal subscales: need for structure and decisiveness (Hirt, Kardes, and Markman, 2004; Neuberg, Judice, and West, 1997) that relate more directly to the seizing and freezing process described above. Need for cognitive closure and has been shown to moderate a large variety of judgment phenomena. For example, research has demonstrated that people who are high in need for cognitive closure exhibit exaggerated correspondence bias (Webster, 1993), are more susceptible to the disrupt-then-reframe influence technique (Kardes, Fennis, Hirt, Tormala, and Bullington, 2007), and are influenced more by price when forming inferences about quality (Cronley et al., 2005). Based on the findings of Kardes et al. (2006), people high in need for cognitive closure may be less sensitive to missing information and more sensitive to debiasing procedures that increase the salience of the missing attribute information. Whereas, people low in need for cognitive closure may be more sensitive to missing information and less sensitive to the debiasing technique. Since people who are high in need for cognitive closure have a desire to form quick judgments ( seize ) and to maintain the judgments as long as possible ( freeze ), they are more likely to draw snap judgments that may involve more heuristic processing and may be more likely to ignore difficult-toprocess information (e.g., missing information). In contrast, people who are low in need for cognitive closure are more concerned with accuracy and less likely to form snap 15

25 decisions, resulting in more systematic processing. As a result, they may be more sensitive to information that is difficult to process (e.g., missing information). Further, Kruglanski and Webster (1996) suggest that selective information processing increases as need for cognitive closure increases. People are more likely to focus on early cues and consider less evidence before forming a judgment. This early cue utilization may be similar to an anchoring effect representing a form of seizing. Kruglanski and Freund (1983) use time pressure to manipulate need for cognitive closure. They demonstrate that anchoring is more pronounced when participants are under high (vs. low) time pressure. Therefore, people who are high in need for cognitive closure may be more likely to anchor on initial important information and be less likely to adjust once the anchor is activated. In omission neglect studies, there are two possible anchors on which people high in need for cognitive closure might seize and freeze when forming their inferential judgments: the implications of the presented information or the implications of the omitted information. If they anchor on the implications of the presented information and do not adjust then their inferential judgment of the omitted attribute should be the same regardless of whether the omission is detected or not. If they anchor on the implications of the omitted attribute and do not adjust, then their inferential judgment of the omitted attribute should be more moderate. 16

26 CHAPTER THREE Experiment 1 In Experiment 1, the underlying process of inferential judgment formation of omitted attribute information is investigated using the point versus range procedure (e.g., Epley et al., 2004). In this study, we manipulate the salience of the omitted attribute, measure either point or range estimates of the cost of the omitted attribute and measure need for cognitive closure. Salience is manipulated to elicit awareness of the omitted attribute, resulting in omission detection. The point vs. range procedure requires that the participants be randomly assigned to either a point estimate condition or a range estimate condition. Our main prediction is that omission detection will result in greater adjustment away from the anchor. Using this methodology, the point estimate is compared to the lower range estimate (the anchor) to see if it differs significantly. Nonsignificance reflects no adjustment whereas significance reflects adjustment. Further, different levels of cognitive closure may result in different processing in the formation of the inferential judgment of the omitted attribute. People low in need for cognitive closure are expected to follow our main prediction for the point versus range procedure described above. They should anchor on the implications of the presented information and adjust based on the implications of the omitted information once it is detected. People high in need for cognitive closure, however, are more likely to anchor ( seize ), but not adjust ( freeze ) using more of a discounting process. If they anchor on the implications of the presented information but do not adjust, they will provide point estimates of the omitted attribute that are not significantly different than the lower range estimate regardless of omission detection. If, instead, they anchor on the implications of 17

27 the omitted information but do not adjust, they will provide point estimates that differ significantly from the lower range estimates when the omission is detected. If the later occurs, their point versus range estimates should not differ from those of the people low in need for cognitive closure. If this is the case, then the point versus range estimate might not be sensitive enough to distinguish between anchoring and adjustment versus discounting. Method A 2 (Salience of Omitted Attribute: Salient or Not) x 2 (Need for Cognitive Closure: High or Low) between subjects design was used. Participants were asked to imagine that they were shopping for a new cell phone plan and provided with a brief description. The primary depended variables of interest were the point versus range estimates and the overall evaluation of the cell phone plan. Manipulations and measures for Experiment 1 can be found in Appendix A. Salience of the Omitted Attribute. The salience of the omitted attribute, roaming fee, was manipulated by either not listing the attribute in the description or listing the attribute information as unknown. By listing the attribute as unknown, it was made salient to the participants that information was omitted from the description, increasing the sensitivity to the omitted attribute information, eliciting omission detection. Need for Cognitive Closure. Need for Cognitive Closure (NFCC) was measured using a 42-item scale (Webster and Kruglanski, 1994). The complete scale can be found in 18

28 Appendix D. After participants completed all the dependent measures and the 42-item Need for Cognitive Closure Scale, a need for cognitive closure index was created by summing the scores (α = 0.83). A median split was performed blocking the participants into either high or low need for cognitive closure conditions. Point vs. Range Estimates. People in the point estimate condition were asked to provide a cost estimate of what they believed the omitted attribute, roaming fee, to be. They were asked to indicate their estimate of the roaming fee on an 11-point scale ($0.00 to $2.00 at $0.20 increments). People in the range estimate condition were asked to provide an estimated upper and lower range for the omitted attribute, roaming fee. What do you assume is the lowest possible roaming fee? What do you assume is the highest possible roaming fee? They were provided with an 11-point scale ($0.00 to $2.00 at $0.20 increments) for each question. Overall Evaluation. Participants indicated their evaluations of the cell phone plan on a 7- point scale ranging from 1 (extremely bad) to 7 (extremely good). Ninety-two undergraduate business students participated for course credit. The participants were randomly assigned to the experimental conditions. Participants were seated at a computer and were informed that the purpose of the study was to investigate consumers attitudes and perceptions. MediaLab software was used to administer the experiment. Participants were asked to imagine that they were shopping for a new cell phone plan. They read a brief description of a new cell phone plan that contained positive 19

29 information on four attributes (anytime minutes, service coverage area, monthly fee, nights and weekends); however, no information was provided about the omitted attribute, roaming fee. They were asked to read the description and evaluate the plan. Once they had completed this task they were not allowed to return to the information page. The participants were then asked to provide an either a point estimate or upper and lower range estimates of the cost of the roaming fee. This was followed by the measure of overall evaluation of the cell phone plan, and the measure of need for cognitive closure. Results A 2 (Salience of Omitted Attribute) x 2 (NFCC) ANOVA was performed on the overall evaluation of the cell phone plan yielding a main effect for Salience (F(1, 88) = 5.28, p <.05). Participants overall evaluations for the plan were greater when the omitted attribute was not salient than when it was salient (Ms = 5.07 vs. 4.58). This finding supports prior debiasing omission neglect findings and confirms that our salience manipulation was effective. No other main effects or interactions were expected or found. Our main prediction for Experiment 1 was that participants in the salience condition would provide point estimates of the roaming fee that are significantly higher than the low range estimates provided by participants in the range condition. The salience of the missing attribute information would result in greater adjustment away from the lower end of the estimated range. This is precisely what we found. The results are presented in Table 1. When the omitted attribute was not salient, the point estimates of the cost was not significantly different than the lowest cost estimate (Ms = $0.57 vs. $0.31 respectively; t(45) = 1.87, ns.). Participants did not adjust away from the lowest 20

30 cost estimate. When the omitted attribute was salient, however, the point estimates of cost differed significantly from the lowest cost estimate (Ms = $1.00 vs. $0.49 respectively; t(43)= 3.18, p <.01). They adjusted their estimated cost upward to a more moderate level. This result did not depend on need for cognitive closure. These results are consistent with an anchoring and adjustment explanation for people who are low in need for cognitive closure, but is inconclusive for people who are high in need for cognitive closure, they could either be anchoring and adjusting or discounting. Discussion In experiment 1, we replicated previous findings by demonstrating that making people aware of omissions results in more moderate overall evaluations. Further, the point versus range measure demonstrated an anchoring and adjustment mechanism. When the omitted attribute information was not salient, we found no significant difference between the lowest cost estimate and the point estimate. People appear to be using the positive attribute information to infer a positive (low cost) estimate of the omitted attribute. When the omitted attribute is salient, however, people provide a significantly higher cost estimate of the omitted attribute. This suggests that people are using the presented attribute information as a cue or reference point. They are anchoring on the implications of the presented attribute information and are adjusting to a more moderate estimate based on the implications of the omitted attribute. Since we did not find an effect of need for cognitive closure in Experiment 1, it is quite possible that the point vs. range procedure may not be sensitive enough to distinguish between anchoring and adjustment and discounting. In the point vs. range 21

31 procedure, either mechanism could result in the higher cost estimate for the omitted attribute when it is salient. People who are low in need for cognitive closure may be anchoring on the implications of the presented information and adjusting based on the implications of the omitted attribute information resulting in a higher cost estimate. People who are high in need for cognitive closure may be discounting their overall evaluations in the inferential judgment, resulting in a similar higher cost estimate. Both may be giving a higher cost estimate but using a different mechanism. As a result, it is necessary to investigate further the differences between anchoring and adjustment and discounting using a different procedure. We do this in Experiment 2, utilizing a cognitive load manipulation. 22

32 CHAPTER FOUR Experiment 2 In Experiment 2, the underlying process of inferential judgment formation of omitted attribute information is investigated using a cognitive load manipulation. In this study, we manipulate the salience of the omitted attribute, manipulate cognitive load, and measure need for cognitive closure. As in Experiment 1, salience is manipulated to elicit awareness of the omitted attribute, resulting in omission detection. It is expected that people will form more positive inferential judgments of the omitted attribute when the omission is neglected than when it is detected. Anchoring and adjustment is thought to be a more effortful than discounting since it is a two-step process. As a result, the cognitive load manipulation should interfere with the anchoring and adjustment process but not the discounting process. People who are under cognitive load should not be able to adjust away from their initial anchor. This should result in more positive inferential judgments of the omitted attribute when people are under cognitive load than when they are not. If people are discounting, however, the cognitive load manipulation should have no effect on the inferential judgment. Although the point versus range procedure in Experiment 1 may not have been sensitive enough to distinguish between anchoring and adjustment and discounting, it did suggest that if people are discounting they are cuing on the implications of the omitted attribute not the implications of the presented information. Therefore, regardless of the load manipulation, people should provide more moderate inferential judgments. Further, different levels of need for cognitive closure may result in different processing in the formation of the inferential judgment of the omitted attribute. People 23

33 who are high in need for cognitive closure have a desire to form quick judgments ( seize ) and to maintain the judgments as long as possible ( freeze ). They are more likely to draw snap judgments that may involve more heuristic processing. People who are low in need for cognitive closure are more concerned with accuracy and less likely to form snap decisions resulting in more systematic processing. It is expected that people low in need for cognitive closure should be more inclined to use all of the information that is available to them in an effort to maximize accuracy of the inferential judgment. Therefore, they should anchor on the implications of the presented information. Once the omission is detected, they should adjust based on the implications of the omitted information, resulting in a more moderate final inferential judgment. People high in need for cognitive closure, however, should have a desire to form a quick judgment, using only the information that is necessary for inferential judgment formation. As a result, they should be more likely to anchor ( seize ) on what they perceive to be most diagnostic, but not adjust ( freeze ), using more of a discounting process. Method A 2 (Salience of Omitted Attribute: Salient or Not) x 2 (Cognitive Load: Load or Not) x 2 (Need for Cognitive Closure: High or Low) between subjects design was used. As in Experiment 1, participants were asked to imagine that they were shopping for a new cell phone plan and provided with a brief description. The primary depended variables of interest were the inferential judgment of the omitted attribute and overall 24

34 evaluation of the cell phone plan. Manipulations and measures for Experiment 2 can be found in Appendix B. Salience of the Omitted Attribute. The salience of the omitted attribute, roaming fee, was manipulated by either not listing the attribute in the description or listing the attribute information as unknown. By listing the attribute as unknown, it was made salient to the participants that information was omitted from the description, increasing the sensitivity to the omitted attribute information, eliciting omission detection. Cognitive Load. Cognitive load was manipulated by having the participants silently rehearse a 9-digit number from the beginning of the study through the end of the evaluative and rating task (e.g., Chun and Kruglanski, 2006). Participants were told that an additional objective of this study was to investigate how well people can perform two different tasks simultaneously. They were asked to silently rehearse a nine-digit number while they are completing the survey, and that they would be asked to reproduce this number later in the survey. Need for Cognitive Closure. Need for Cognitive Closure (NFCC) was measured using a 42-item scale (Webster and Kruglanski, 1994). The complete scale can be found in Appendix D. After participants completed all the dependent measures and the 42-item Need for Cognitive Closure Scale, a need for cognitive closure index was created by summing the scores (α = 0.85). A median split was performed blocking the participants into either high or low need for cognitive closure conditions. 25

35 Inferential Judgment. Participants were asked to rate the cell phone plan on the omitted attribute using a 7-point scale ranging from 1 (extremely bad) to 7 (extremely good). This measure was taken to provide a rating based measure of the inference of the omitted attribute, roaming fee. Overall Evaluation. Participants indicated their evaluations of the cell phone plan on a 7- point scale ranging from 1 (extremely bad) to 7 (extremely good). One hundred and nineteen undergraduate business students participated for course credit. The participants were randomly assigned to the experimental conditions. Participants were seated at a computer and were informed that the purpose of the study was to investigate consumers attitudes and perceptions. MediaLab software was used to administer the experiment. Participants were asked to imagine that they were shopping for a new cell phone plan. They read a brief description of a new cell phone plan that contained positive information on four attributes (anytime minutes, service coverage area, monthly fee, nights and weekends); however, no information was provided about the omitted attribute, roaming fee. They were asked to read the description and evaluate the plan. Once they had completed this task they were not allowed to return to the information page. The participants were then asked to provide an overall evaluation of the cell phone plan. This was followed by the inferential judgment measure and the need for cognitive closure scale. 26

36 Results As a manipulation check for the cognitive load manipulation, participants were asked, How difficult was it for you to concentrate carefully on the product evaluation? (7-point scale, 1 = not at all difficult; 7 = extremely difficult). A 2 (Salience of Omitted Attribute) x 2 (Cognitive Load) x 2 (NFCC) ANOVA revealed a main effect for Cognitive Load (F(1, 111) = 6.84, p <.01). Participants found it more difficult to concentrate when they were under cognitive load than not (M = 3.52, M = 2.70 respectively). The cognitive load manipulation had the desired effect. No other main effects or interactions were expected or found. A 2 (Salience of Omitted Attribute) x 2 (Cognitive Load) x 2 (NFCC) ANOVA was performed on the overall evaluation of the cell phone plan yielding a main effect for Salience (F(1, 111) = 4.20, p <.05). Participants overall evaluations for the plan were greater when the omitted attribute was not salient than when it was salient (M = 5.25, M = 4.88 respectively). This finding supports prior debiasing omission neglect findings and confirms that our salience manipulation was effective. No other main effects or interactions were expected or found. A 2 (Salience of Omitted Attribute) x 2 (Cognitive Load) x 2 (NFCC) ANOVA performed on the inferential judgment revealed a main effect for Salience (F(1, 111) = 24.15, p <.001). Participants rated the omitted attribute, roaming fee, as more positive when it was not salient than when it was (Ms = 3.86 vs. 2.74, respectively). The increased salience of the omitted attribute information made participants sensitive to the fact that it was missing, resulting in a more moderate inferential judgment. Further, although it is possible that cognitive load may also impact omission detection or people s 27