The p-value fallacy and how to avoid it.

Null hypothesis significance tests are commonly used to provide a link between empirical evidence and theoretical interpretation. However, this strategy is prone to the "p-value fallacy" in which effects and interactions are classified as either "noise" or "real" based on whether the associated p value is greater or less than .05. This dichotomous classification can lead to dramatic misconstruals of the evidence provided by an experiment. For example, it is quite possible to have similar patterns of means that lead to entirely different patterns of significance, and one can easily find the same patterns of significance that are associated with completely different patterns of means. Describing data in terms of an inventory of significant and nonsignificant effects can thus completely misrepresent the results. An alternative analytical technique is to identify competing interpretations of the data and then use likelihood ratios to assess which interpretation provides the better account. Several different methods of calculating the likelihood ratios are illustrated. It is argued that this approach satisfies a principle of "graded evidence," according to which similar data should provide similar evidence.     

Rule learning in rats: serial tracking in interleaved patterns

Humans have the ability to chunk together information from nonadjacent serial positions in sequential patterns. For example, human subjects can extrapolate the pattern, A-M-B-N-C-O-D-P-E-..., to find the missing element, Q, by sorting pattern elements into two component interleaved subpatterns: A-B-C-D-E and M-N-O-P-... Two experiments investigated the ability of rats to reorganize pattern elements from nonadjacent serial positions into chunks not presented by the experimenter. Rats learned either a structured or unstructured sequence interleaved with elements of a repeating sequence (experiment 1) or an alternation sequence (experiment 2). In both experiments, rats learned the interleaved subpatterns at different rates. Acquisition rate was correlated with the structural properties of component subpatterns and the nature of the rules required to describe the interleaved subpatterns. The results indicate that rats are sensitive to the organization of nonadjacent elements in serial patterns and that they can detect and sort structural relationships in interleaved patterns. Received: 7 September 1998 / Accepted after revision: 27 January 1999     

Chunking, rule learning, and multiple item memory in rat interleaved serial pattern learning

Nonhuman animals, like humans, appear sensitive to the structure of the elements of sequences, perhaps even when the structure relates nonadjacent elements. In the present study, we examined the contribution of chunking, rule learning, and item memory when rats learned serial patterns composed of two interleaved subpatterns. In one group, the first interleaved subpattern was a formally simple sequence, whereas in two other groups the first subpattern was formally more complex, containing 2 or 4 violation elements, respectively. In all groups, the second interleaved subpattern encountered was formally simple. Evidence from the study suggests that rats chunked their interleaved patterns into component subpatterns, that is, they cognitively sorted pattern elements to form chunks based on nonadjacent structural relationships that can be characterized as rules. They also learned interitem associations via traditional discrimination learning to use adjacent elements as compound or configural cues for later events in the sequence. Thus, the evidence suggests that rats used chunking, rule learning, and interitem association learning concurrently to master these complex patterns.     

Preposition-phrase attachment in noun phrases

This paper examines the ambiguity of noun phrases (NPs) with postmodifying preposition phrases (PPs), such as the triangle next to the circle below the square. This ambiguity is attributable in part to the difference in attachment sites for the second PP. If it attaches low, it modifies just the NP that is the object of the first preposition, and the resulting structure is right branching. If it attaches high, it modifies the entire preceding NP, and the resulting structure is left branching. However, each of these structures itself has two distinct interpretations. In the case of the high-attachment structure, these different interpretations have been previously noted; we call them stacking and coordinating. In the stacking interpretation, each PP modifies the entire NP to its left, whereas in the coordinating interpretation, it modifies just the head noun to its left (the first noun in the construction). In the case of the low-attachment structure, only the interpretation corresponding to the coordinating one has been noted; we call it alternating. However, a fourth distinct interpretation is possible, which corresponds to the stacking interpretation of the highattachment structure; we call it stuffing. In the alternating interpretation, each preposition has scope only over the head of the NP that is its complement. In the stuffing interpretation, each preposition has scope over its entire complement. In a pilot study, we found that the interpretations based on low attachment are preferred to those based on high attachment by a 21 ratio. Of the two low-attachment interpretations, alternating is preferred to stuffing by a 201 ratio. However, of the two high-attachment interpretations, coordinating is preferred to stacking by only a 21 ratio. In a second pilot study, we examined the pattern of interpretations of phrases with four PP postmodifiers of an NP, which in principle have 112 distinct interpretation types. Eleven of these types were noted in the experimental materials. We provide a detailed analysis of these types and note that the relative preference of the various interpretations found in the first study is preserved.     

Strategies of information search in causal analysis

Five experiments investigated the relative prevalence of three search patterns that individuals may use in explaining events with multiple possible causes: (1) parallel search—pursue information about all possible causes before making any causal judgments, (2) serial search—clarify the role of one cause before considering any others, (3) truncated search—clarify the role of one cause without proceeding to consider other causes. In Experiments 1, 2, and 3, subjects were told about an event, two or three nonexclusive possible causes of the event, and a fact implicating one of the suggested causes as influencing the event. Subjects were asked for the question whose answer would help them most in explaining the event. In each experiment, subjects preferred to clarify the role of the implicated cause, a pattern congruent with both the serial and truncated search strategies. Results of a fourth experiment indicated that these preferences reflect a truncated rather than a serial search. A final experiment demonstrated that the preference for information about the implicated cause persists even with the opportunity for a more extended search.     

An evaluation of three methods of saying "no" to avoid an escalating response class hierarchy

We evaluated the effects of three different methods of denying access to requested high-preference activities on escalating problem behavior. Functional analysis and response class hierarchy (RCH) assessment results indicated that 4 topographies of problem behaviors displayed by a 13-year-old boy with high-functioning autism constituted an RCH maintained by positive (tangible) reinforcement. Identification of the RCH comprised the baseline phase, during which computer access was denied by saying "no" and providing an explanation for the restriction. Two alternative methods of saying "no" were then evaluated. These methods included (a) denying computer access while providing an opportunity to engage in an alternative preferred activity and (b) denying immediate computer access by arranging a contingency between completion of a low-preference task and subsequent computer access. Results indicated that a hierarchy of problem behavior may be identified in the context of denying access to a preferred activity and that it may be possible to prevent occurrences of escalating problem behavior by either presenting alternative options or arranging contingencies when saying "no" to a child's requests.     

Ambiguity and structural information in the perception of reversible figures

The perspective reversals elicited by a set of drawings based on the Mach truncated pyramid are examined. We obtained each pattern of the set from the previous one by adding to it some graphic cues, which were easily integrated into one of the two competing interpretations, thus reducing step by step the ambiguity of the basic pattern. The phenomenological model, proposed to link the mean times of both alternative interpretations with their complexities, is in close agreement with our experimental data. Furthermore, different aspects of such data are well described by the model equations: The measure of the prevalence of the supported interpretation is well correlated with the difference in complexity between the two alternative interpretations; the two different trends of the mean time of the unfavored interpretation, found in the data obtained from different observers as a function of the various patterns of the set, are well fitted by the model without the need for any specific additional hypothesis.     

The interpretation of ambiguous trimorphemic words in sentence context

Many trimorphemic words are structurally and semantically ambiguous. For example, unlock-able can either be un-lockable (cannot be locked) or unlock-able (can be unlocked). Which interpretation is preferred and whether the preceding sentence context affects the initial interpretation is not clear from prior research. The present experiment embedded ambiguous trimorphemic words in sentence contexts, manipulated whether or not preceding context disambiguated the meaning, and examined the pattern of fixation durations on the ambiguous word and the remainder of the text. The results indicated that the unlock-able interpretation was preferred; moreover, preceding context did not exert a significant effect until the eyes had initially exited from the target word.     

Using the regulation of accuracy to study performance when the correct answer is not known

We examined memory performance in multiple‐choice questions when correct answers were not always present. How do participants answer when they are aware that the correct alternative may not be present? To answer this question we allowed participants to decide on the number of alternatives in their final answer (the plurality option), and whether they wanted to report or withhold their answer (report option). We also studied the memory benefits when both the plurality and the report options were available. In two experiments participants watched a crime and then answered questions with five alternatives. Half of the questions were presented with the correct alternative and half were not. Participants selected one alternative and rated confidence, then selected three alternatives and again rated confidence, and finally indicated whether they preferred the answer with one or with three alternatives (plurality option). Lastly, they decided whether to report or withhold the answer (report option). Results showed that participants’ confidence in their selections was higher, that they chose more single answers, and that they preferred to report more often when the correct alternative was presented. We also attempted to classify a posteriori questions as either presented with or without the correct alternative from participants’ selection. Classification was better than chance, and encouraging, but the forensic application of the classification technique is still limited since there was a large percentage of responses that were incorrectly classified. Our results also showed that the memory benefits of both plurality and report options overlap.     

Altruism and selfishness

Many situations in human life present choices between (a) narrowly preferred particular alternatives and (b) narrowly less preferred (or aversive) particular alternatives that nevertheless form part of highly preferred abstract behavioral patterns. Such alternatives characterize problems of self-control. For example, at any given moment, a person may accept alcoholic drinks yet also prefer being sober to being drunk over the next few days. Other situations present choices between (a) alternatives beneficial to an individual and (b) alternatives that are less beneficial (or harmful) to the individual that would nevertheless be beneficial if chosen by many individuals. Such alternatives characterize problems of social cooperation; choices of the latter alternative are generally considered to be altruistic. Altruism, like self-control, is a valuable temporally-extended pattern of behavior. Like self-control, altruism may be learned and maintained over an individual's lifetime. It needs no special inherited mechanism. Individual acts of altruism, each of which may be of no benefit (or of possible harm) to the actor, may nevertheless be beneficial when repeated over time. However, because each selfish decision is individually preferred to each altruistic decision, people can benefit from altruistic behavior only when they are committed to an altruistic pattern of acts and refuse to make decisions on a case-by-case basis.     

Patterns of Parental Control in Kuwaiti Society

The study examined the applicability of Baumrind's patterns of parental control to Kuwaiti society. The patterns consisted of the three main patterns: authoritative, authoritarian, and permissive; and two subpatterns derived from Baumrind's writings. A 50-item questionnaire that tapped child-rearing views was developed, based on the characteristics of the patterns. The questionnaire was administered to 400 mother-father pairs, all of them University students. Results indicated that educated Kuwaiti parents regard the authoritative pattern to be the most appropriate for parental control. The additional finding is indicative of the continuing influence of traditional social values in Kuwait society. On the whole, the study demonstrates the possibility of applying western models of socialisation to non-western societies.     

Neon color spreading and structural information measures

This article presents a study on Van Tuijl’s (1975) neon effect. The neon effect can be described as an illusory spreading of color around the colored elements of an otherwise black line pattern. The observer has a strong impression of colored light projected onto a lattice of black lines. The hypothesis is advanced that the neon effect will only result if the structural relationships between black and colored line elements in the pattern are such that a neon interpretation is the most efficient interpretation that can be given of the pattern. The necessity of this approach to the neon phenomenon emanates from the inadequacy of alternative, more simple, explanations, such as aberrations of peripheral perceptual mechanisms or the presence in the pattern of easily definable stimulus features. To subject the hypothesis proposed above to experimental test, a precise quantification of its central concept, the efficiency of pattern interpretations, is needed. To that end, Leeuwenberg’s (1971) coding language for sequential patterns is introduced. By means of the coding language, pattern interpretations can be represented in a pattern code, the length of which is inversely proportional to the efficiency of the interpretation coded. Several possible interpretations of color differences between the elements of line patterns are discussed, and it is shown how the efficiency of each of them can be determined. Next, in two experiments, the efficiency of the neon interpretationrelative to that of alternative interpretations of color differences in line patterns is varied, by manipulating the structural relations between black and colored line elements, and the dependency of the neon effect on the relative efficiency of the neon interpretation is demonstrated. Implications of the findings are discussed.     

Modal semantics,modal dynamics and the problem of state preparation

It has been suggested that the Modal Interpretation of Quantum Mechanics (QM) is "incomplete" if it lacks a dynamics for possessed values. I argue that this is only one of two possible attitudes one might adopt toward a Modal Interpretation without dynamics. According to the other attitude, such an interpretation is a complete interpretation of QM as standardly formulated, an interpretation whose innovation is to attempt to make sense of the quantum realm without the expedient of novel physics. Then I explain why this attitude, though available, is unattractive. Without dynamics, the Modal Interpretation vanquishes the measurement problem only, it seems, to succumb to the problem of state preparation. On this view, the Modal Interpretation needs dynamics not to be an interpretation at all, but to be an adequate one. I review reasons to suspect that the dynamics which would best suit the Modal Interpretation--a dynamics equivalent to a set of two time transition probabilities of the sort used to solve the preparation problem--is not a dynamics the interpretation can have. I close with a brief discussion of versions of the Modal Interpretation that may not succumb to the considerations presented here.     

Are spoken surface structure ambiguities perceptually unambiguous?

This study was devised to ascertain the extent to which objective intonational cues determine the listener's interpretation of surface structure ambiguities. Highly biased ambiguities (as determined by a pretest) were recorded with intonation patterns appropriate to either the more probable (high-bias) interpretation or the less probable (low-bias) interpretation. Each reading was paired with three context questions: a question appropriate only to the high-bias reading, one appropriate only to the low-bias reading, and a neutral question appropriate to either interpretation. Subjects provided appropriateness judgments for the question-answer pairs, and were timed on their responses. A second task involved paraphrasing the answer in each question-answer pair regardless of compatibility. The results indicated that perception of intonation is affected by the interpretive bias of an ambiguous sentence, and that the strength of the preferred reading is attenuated to a greater degree by an opposing context than by an opposing intonation.This research was carried out at the City University of New York, and was supported in part by the Faculty Research Award Program under Grant # 10668 to H. S. Cairns.     

Sensations, cognitions and the perception of cues associated with expected and unexpected panic attacks

Panic attacks may be perceived by patients as either cued or uncued (spontaneous) and either expected or unexpected. The purpose of the present study was to examine the prevalence and characteristics of these types of panic. Twenty-six panic disorder patients with mild avoidance and 18 with moderate or severe avoidance were instructed to complete a questionnaire during or immediately following each of three consecutive naturally occurring panic attacks they experienced. They were asked to rate the extent to which they expected the panic attack to occur, whether they felt it was associated with an external panic "cue" (e.g. a shopping mall), whether they would expect to panic again in similar circumstances, their mood, present level of life stress, and fear and severity of their body sensations and disturbing cognitions. Results indicated that from a sample of 92 questionnaires, each representing a separate panic, nearly 70% of panic attacks were rated as cued-expected and only one panic was rated as uncued-expected. The other two categories each comprised about 15% of all panic attacks. There were few reported differences in body sensations and cognitions reported as a function of type of panic and no differences with regard to extent of agoraphobic avoidance. Expected panic was associated with a higher expectation of future panic in similar circumstances.     

Alan Baron: A pioneer in translational science

Primates take longer to choose between alternatives with smaller differences in value. This effect—a particular instance of the distance effect in symbolic comparisons—has not been replicated in birds. Instead, birds appear to respond independently to each alternative, such that the latency to choose depends primarily on the alternative of highest value. Three experiments tested for the distance effect in pigeons under conditions not previously considered. Experiment 1 presented pigeons with forced‐ and binary free‐choice trials, where each alternative was one of three possible delays to reinforcement (4, 8, and 16 s). Pigeons were exposed to the choice stimuli for different amounts of time and with different sample response requirements prior to the choice response. Experiment 2 added a fourth (0‐s delay) alternative. Experiment 3 substituted the 16‐s delay with a second 4‐s delay. In all experiments, pigeons systematically chose the shortest delay to reinforcement. Latency to choose the 4‐s delay did not vary when choosing against the 8‐s or 16‐s delay, regardless of whether choice stimuli were exposed for the duration of nine pecks (Experiment 1), or whether a 0‐s delay alternative was sometimes present (Experiment 2). Latency to choose the preferred of two identical alternatives (4‐s vs. 4‐s) was shorter than the latency to choose between different alternatives (4‐s vs. 8‐s; Experiment 3); this is the opposite of a distance effect. These results show no evidence of a distance effect in pigeon choice, consistent with the hypothesis that pigeons respond independently to each choice alternative.     

The perception of assimilation and brightness contrast as derived from code theory

It is shown that assimilation and brightness contrast effects are evoked by structural aspects of patterns. In a pilot experiment, variously shaped gray patterns were used as stimuli. The backgrounds used with each of these shapes were identical: half black and half white. If the gray area against the black part was judged to be more black than the gray area against the white part, an assimilation effect will have occurred; when the reverse occurred, this was called a contrast effect. The task was to rank-order the stimuli on the assimilation-contrast scale. It is argued that the two effects are due to two different interpretations, each derivable from a different code of a pattern. The simpler the contrast code is with respect to the assimilation code, the more it will be perceptually preferred. In the specification of pattern complexity, structural information theory was used. A significant correlation was discovered between the theoretical preference for the contrast interpretation and the contrast preference of subjects.     

Coordination of the upper and lower extremities

Simultaneous walking and hand clapping were utilized to examine the patterns of coordination between upper and lower limbs. Eighteen normal adult subjects were filmed at high speed under instructions to: (a) walk and clap at a self-determined “preferred” speed, (b) walk as fast as possible while clapping at the preferred speed, (c) walk at the preferred speed while clapping as fast as possible and (d) walk and clap as fast as possible. Temporal data and individual patterns of phase relations were analyzed. Results indicated a disruption of the preferred clap cycle when combine with fast walking. The degree of disruption was a function of the individual coordinative pattern at the preferred rate. It is concluded that: (a) the temporal patterning of the clap cycle can be dictated by the step cycle, (b) heel strike is the point about which the clap cycle is modulated, and (c) subjects can select from various modes of phase linkage.