Process Of Hypothesis Testing Research Articles

Deficits of problem-solving ability in patients with focal brain damage: neuropsychological investigation of prediction and hypothesis behavior.

Deficits of problem-solving ability in focal brain-damaged patients, with special reference to frontal lobe dysfunction, were investigated by two neuropsychological tests: Temporal rule induction test and Hypothesis-testing measure. Subjects consisted of 84 chronic brain-damaged patients (31 with anterior cerebral lesions and 53 with posterior lesions). The study's aim was to investigate the effects of frontal lobe damage on two aspects of inductive reasoning, prediction and hypothesis behavior. When prediction was examined by Temporal rule induction test, patients with anterior lesions showed deficits in predicting a rule, even in the memory-aid condition in which memory factors were excluded. The poor results on Temporal rule induction test in frontal patients did not appear to be related to deficits in temporal integration, which is generally interpreted as frontal dysfunction. Rule induction may be impaired by frontal damage whenever complicated information-processing is required, even when temporal succession is not involved. Second, two stages of hypothesis behavior, hypothesis-formation and hypothesis-testing, were evaluated. Patients with anterior lesions showed impairment in hypothesis-formation. Their decreased fluency in hypothesis production affected the hypothesis-testing process. However, frontal patients committed fewer errors, most of which were perseverative (lose-stay errors) on hypothesis-testing. Patients with posterior lesions revealed other characteristic errors, such as inconsistent responses and divergent-type errors (improper lose-shift errors). The hemispheric site of the lesion affected only the ability to maintain a hypothesis (win-shift errors). The results illustrated the differences in problem-solving deficits in these two groups of patients. Disturbed prediction of future events, decreased hypothesis fluency, and abnormal lose-stay behavior in patients with frontal lobe damage may be crucial factors in coping with daily problem-solving situations.

ARTMAP: Supervised real-time learning and classification of nonstationary data by a self-organizing neural network

This article introduces a new neural network architecture, called ARTMAP, that autonomously learns to classify arbitrarily many, arbitrarily ordered vectors into recognition categories based on predictive success. This supervised learning system is built up from a pair of Adaptive Resonance Theory modules (ART a and ART b ) that are capable of self-organizing stable recognition categories in response to arbitrary sequences of input patterns. During training trials, the ART a module receives a stream [ a ( p) ] of input patterns, and ART b receives a stream [ b ( p) ] of input patterns, where b ( p) is the correct prediction given a ( p) . These ART modules are linked by an associative learning network and an internal controller that ensures autonomous system operation in real time. During test trials, the remaining patterns a ( p) are presented without b ( p) , and their predictions at ART b are compared with b ( p) . Tested on a benchmark machine learning database in both on-line and off-line simulations, the ARTMAP system learns orders of magnitude more quickly, efficiently, and accurately than alternative algorithms, and achieves 100% accuracy after training on less than half the input patterns in the database. It achieves these properties by using an internal controller that conjointly maximizes predictive generalization and minimizes predictive error by linking predictive success to category size on a trial-by-trial basis, using only local operations. This computation increases the vigilance parameter ϱ a of ART a by the minimal amount needed to correct a predictive error at ART b . Parameter ϱ a calibrates the minimum confidence that ART a must have in a category, or hypothesis, activated by an input a ( p) in order for ART a to accept that category, rather than search for a better one through an automatically controlled process of hypothesis testing. Parameter ϱ a is compared with the degree of match between a ( p) and the top-down learned expectation, or prototype, that is read-out subsequent to activation of an ART a category. Search occurs if the degree of match is less than ϱ a . ARTMAP is hereby a type of self-organizing expert system that calibrates the selectivity of its hypotheses based upon predictive success. As a result, rare but important events can be quickly and sharply distinguished even if they are similar to frequent events with different consequences. Between input trials ϱ a relaxes to a baseline vigilance ϱ a . When ϱ a is large, the system runs in a conservative mode, wherein predictions are made only if the system is confident of the outcome. Very few false-alarm errors then occur at any stage of learning, yet the system reaches asymptote with no loss of speed. Because ARTMAP learning is self-stabilizing, it can continue learning one or more databases, without degrading its corpus of memories, until its full memory capacity is utilized.

Information processing strategies in counselor hypothesis testing: The role of selective memory and expectancy.

The issue of confirmatory bias in counselors' clinical hypothesis testing was explored. Previous research has suggested that counselors are unbiased when constructing questioning strategies to test a client hypothesis. This study proceeded on the assumption that questioning is only the beginning of the hypothesis-testing process. In 2 experiments the way counselors remembered information about a client was examined, and information from a client narrative was selected. In Experiment 1 experienced counselors remembered more confirmatory than disconfirmatory information, even when the report they reviewed contained more disconfirmatory information. In Experiment 2 counselors in training selected more confirmatory than disconfirmatory information, even when the report they reviewed contained more disconfirmatory information. Conclusions of the study were the following: Counselors need to be aware of these biases and counselor education should explicitly train counselors to avoid them.

Taxonomy of 130 cases of youth suicide.

Taxonomy is an essential prelude to scientific understanding and the heuristic process of hypothesis testing. Some taxonomic work exists for adult suicides (2), but no work on numerical taxonomy with completed suicide in youth can be located. In part this reflects the rarity of youth suicide. But with the dramatic increase in rates in the past decade, enough cases have become available for analysis (4). The present description is based on principal component analysis of 23 demographic and clinical variables identified by the Medical Examiner of Alberta for 130 individuals (16% female) aged 10 to 20 who killed themselves berween 1978 and 1984 (1). Six rotated components of the 23 variables accounted for 53% of total variance. Cluster analysis of six factor scores for each individual using the newest ne~ghbour algorithm (3) identified six groups of 10 or more cases, with 19 cases falling into groups with fewer than 10 cases each. A variable typified a group if it had a significantly different prevalence (x2, p< .05) from all remaining cases.

Social Hypothesis Testing and the Role of Expertise

Research on social hypothesis-testing processes has demonstrated that there is a strong preference for seeking and using hypothesis-confirming evidence when testing hypotheses about other people. An experiment was conducted to examine the extent to which expertise in a particular knowledge domain represents a delimiting condition of this inferential tendency. Expert and novice subjects completed a hypothesis-testing recall task. Recall differences in line with the different strategies commonly used by experts and novices on problem-solving and reasoning tasks were predicted. As expected, novices recalled more hypothesis-matching evidence after a delay interval, regardless of the nature of the hypothesis to be tested. Expert recall, by contrast, was not characterized by this confirmatory preference when experts tested the hypothesis inside their domain of expertise. The extent to which these expert/novice differences provide support for motivated social cognition is discussed.

Hierarchy in picture segmentation: a stepwise optimization approach

A segmentation algorithm based on sequential optimization which produces a hierarchical decomposition of the picture is presented. The decomposition is data driven with no restriction on segment shapes. It can be viewed as a tree, where the nodes correspond to picture segments and where links between nodes indicate set inclusions. Picture segmentation is first regarded as a problem of piecewise picture approximation, which consists of finding the partition with the minimum approximation error. Then, picture segmentation is presented as an hypothesis-testing process which merges only segments that belong to the same region. A hierarchical decomposition constraint is used in both cases, which results in the same stepwise optimization algorithm. At each iteration, the two most similar segments are merged by optimizing a stepwise criterion. The algorithm is used to segment a remote-sensing picture, and illustrate the hierarchical structure of the picture.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The ART of adaptive pattern recognition by a self-organizing neural network

The adaptive resonance theory (ART) suggests a solution to the stability-plasticity dilemma facing designers of learning systems, namely how to design a learning system that will remain plastic, or adaptive, in response to significant events and yet remain stable in response to irrelevant events. ART architectures are discussed that are neural networks that self-organize stable recognition codes in real time in response to arbitrary sequences of input patterns. Within such an ART architecture, the process of adaptive pattern recognition is a special case of the more general cognitive process of hypothesis discovery, testing, search, classification, and learning. This property opens up the possibility of applying ART systems to more general problems of adaptively processing large abstract information sources and databases. The main computational properties of these ART architectures are outlined and contrasted with those of alternative learning and recognition systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Note on subjects' hypotheses in multiple-cue probability learning

Subjects' hypotheses in multiple-cue probability learning was studied by trial-by-trial verbal reports in tasks with linear and nonlinear cue-criterion relations. In accordance with earlier findings, the results of the present experiment show that subjects learned linear tasks rapidly, while nonlinear tasks were not learned at all. The subjects' verbal hypotheses show that the subjects were concerned with rules for combining cue values, rather than with cue-criterion functions. This explains why the subjects fail to learn nonlinear multiple-cue tasks. It also shows that, although the subjects seem to learn multiple-cue tasks through a hypothesis testing process of the same kind as in single-cue probability tasks, the hypotheses tested in multiple-cue tasks are different from those tested in single-cue tasks. Finally, the present results suggest that the picture of the subjects' cognitive models of multiple-cue probability learning tasks provided by the customary multiple regression analysis may be fundamentally misleading in that it suggests that the subjects learn the validity of each cue rather than a combination rule.

Adventures in The Scientific Method (TSM)

The author describes a project that allows students to learn the scientific method by going through the entire process of data collection, hypothesis generation, data analysis, and hypothesis testing. The project concerns “book carrying behavior.”

Paired Versus Individual Learning in Testing Hypotheses

Abstract Sixty male and female subjects solved two sets of concept attainment tasks in two sessions separated by 48 hr. Subjects solved the first set as individuals or in same-sex pairs. All subjects solved the second set as individuals. The hypothesis-testing processing of those subjects initially trained as pairs fell below that of the individually trained subjects in the transfer session. It is suggested that group monitoring of inductive problem solving leads to negative group-to-individual transfer of hypothesis-testing processes.

Reading Comprehension Testing in German

Comprehensive testing is a challenge to all second-language educators. In layman's terms, teachers have the obligation to measure the students' understanding of the text. Since there is no consensus of opinion on what it means to understand a passage, the task is difficult indeed. The psycholinguistic models of Goodman and Smith describe the process whereby the reader interacts with the graphic input while attempting to reconstruct the message encoded by the writer.' In addition the more prior knowledge the reader possesses about the language and the world in general, the less visual input is required to comprehend the text. Their models are frequently labeled top-down because they give priority to the existing knowledge in the reader's head, not to the printed word. According to Goodman and Smith, success in comprehension depends on the extent to which the reader's reconstructed meaning agrees with the author's intended message. Goodman proposes a theory of psycholinguistic universals that is specifically second language oriented.2 He maintains that the strategies that readers use to comprehend a text are transferred from the first language setting to the second language setting. Therefore, a fluent reader uses the same basic strategies to process information and extract meaning from print in any language. Although not extensively investigated from the second language learning perspective, Goodman's model dominates the second language reading literature. Likewise, the evidence concerning the strategies used by beginning and intermediate second language readers is not impressive. Clarke posits that a short-circuit effect prevents the transfer of fluent reading skills from the first language to the second language.3 According to Clarke, the second language reader's lack of knowledge of the target language impedes the predictive hypothesis testing process that is the critical element of comprehension in Goodman's model. The lower level second language reader is not able to use the orthographic, syntactic, semantic, and discourse level cues that are available in the passage because of the basic lack of fluency in the target language. Although some resist the notion that the reading process should be segmented, Thorndike and Klausmeier contend that reading is thinking and that reading comprehension is based on many subskills.4 They maintain that efforts to increase comprehension should concentrate on developing analytic abilities. Among the multitude of subskills of comprehension that are mentioned in the literature, the following are frequently cited: establishing word meaning; identifying main ideas; identifying details; recognizing sequence; identifying cause-effect relation-

The role of negative factors in changes in career selection by medical students.

The authors in the present study assessed the extent to which negative factors influenced changes in career selection among medical students. Ninety-eight graduating medical students completed a retrospective career choice questionnaire that ascertained the areas of medicine in which they intended to practice and when in their medical curriculum they made this choice, whether this choice represented a change, and, if so, when and why did such a change occur. Responses to these questions indicated that 84 percent of all changes were due to some negative factor about the initial choice, while only 16 percent were due to positive factors concerning a new choice. The results were also classified with regard to disciplines losing and gaining students and the points during the course of study when changes occurred. It was concluded by the authors that time of change and knowledge of reasons for change have different implications for various medical specialties. Medical career selection was likened to the process of hypothesis generation and testing.

The Problem of Missing Data on Spatial Surfaces

Abstract Although the problem of missing data arises in most branches of the discipline, it has received little systematic treatment in the geographical literature. In an effort to overcome this deficiency, this paper reviews a number of methods for approaching the problem. Of the three classes of solutions—ad hoc, cartographic interpolation, and statistical—the statistical approaches appear to be preferable. In this review a modified version of the Orchard and Woodbury missing-information principle receives the greatest emphasis because it combines classical statistical theory with trend surface and spatial autoregressive models. Although the best solution of all is to return to the experimental situation in order to collect supplementary data, this is often impractical or impossible. The analyst should then consider the estimation techniques presented here. The methods used to address the missing data problem thus become an important stage in the overall process of experimental design, sampling, and hypothesis testing.

Testing Hypotheses about Other People

Male and female participants formulated question-asking strategies to test hypotheses about the personalities of other people. For some participants, the hypothesis-testing task was defined explicitly as a falsification task (i.e., assessing the extent to which the hypothesis was not true). For other participants, the hypothesis-testing task was defined explicitly as a verification task (i.e., assessing the extent to which the hypothesis was true). Participants performed the falsification task by preferentially soliciting behavioral evidence that would disconfirm the hypothesis. Participants performed the verification task by preferentially soliciting behavioral evidence that would confirm the hypothesis. Implications for understanding hypothesis-testing processes are discussed.

An Effect of Probe Trials on Selection Strategies in Problem Solving

Summary The use of probe trials to investigate hypothesis-testing behavior was investigated as a variable that may affect the hypothesis-testing process itself. Shift behavior by 96 male and female college students in an optional shift task was used as the dependent variable because it could be evaluated independent of the presence or absence of probe trials. The number of options, two or three, available on the shift task was also manipulated in order to test the hypothesis that, if probe trials cause the adoption of a more efficient shift strategy like Local Consistency, an increase in options would result in a decrease in within-dimension shifts. The data were in support of the hypothesis that probe trials have an effect on an individual's strategy for selecting hypotheses following negative feedback: 89% of the no-probe-trial participants made within-dimension shifts, with no effect following from an increase in options, while 56% of the probe-trial participants made within-dimension shifts, with a de...

Preliminaries to a psychology of inference

This paper presents a general pretheoretical framework for the study of inference. The framework is that of Social Judgment Theory which has been developed from Brunswik's probabilistic functionalism. The first section discusses the fundamental theoretical ideas and methodological principles. Important among these is the stress on the need to study the relation between the cognitive system and the inference task using parallel concepts for describing the cognitive system and the task, the theory of cognitive tasks, and the methodology of formal representative sampling. The second section describes a series of experimental paradigms developed from the basic ideas discussed in the first section. The third, and final section gives some examples of actual empirical research, mainly research concerned with the hypothesis testing process by means of which subjects learn inference tasks, studies on cognitive skills in using various rules for making inferences, new conceptions of feedback, research on the effects of feedforward, and interpersonal learning.

A test of the self-perception explanation of the effects of rewards on intrinsic interest

An experiment was conducted to test the proposition that rewards undermine or enhance intrinsic interest in a task to the extent that individuals interpret their behavior as being motivated by the reward. It was predicted that when subjects were denied the opportunity to develop and confirm this attribution, rewards would not produce an undermining effect, but rather would enhance dispositions and behavior. Subjects were recruited to evaluate a new sugar-free soft drink. Two levels of incentives (reward-no reward), two levels of examination (opportunity-no opportunity), and three levels of outcome (good-neutral-poor) were employed. The results support the prediction that an incentive's effect depends on the examination opportunity. In the examination condition, rewarded subjects attributed their behavior more to external factors than did unrewarded subjects, but gave more negative product evaluations only after tasting it. In the no examination condition, there were no differences in the attributions made by rewarded and unrewarded subjects, and rewarded subjects were more positively disposed toward the product both before and after tasting it. These results are explained as a consequence of two properties of rewards, enhancement through reinforcement and undermining through discounting, and of hypothesis-testing processes.

Hypothesis-testing processes in social interaction.

In the course of social relationships, individuals often attempt to make judgments about the personal attributes of other people. At times, this quest for knowledge may involve the testing of hypotheses about other people. When we form our early impressions of new acquaintances, we may wish to test hypotheses based upon our expectations about their personal dispositions (Is this new acquaintance as friendly as a mutual friend has

Hypothesis-testing processes in social interaction.

Hypothesis-testing processes in social interaction.

Statistical Power: Derivation, Development, and Data-Analytic Implications

In 1933, Neyman and Pearson introduced the interrelated concepts of statistical power and Type II error in response to a fundamental asymmetry in the hypothesis testing process. With few exceptions, however, statistical power did not become a regular textbook inclusion until some 30 years later. Modern concern for power evolved naturally from the “significance test controversy,” and was further stimulated by Cohen’s (1962) review in the Journal of Abnormal and Social Psychology. To date, eight power-analytic surveys have been conducted. Generally, the average power estimates derived from these analyses have been quite low. Providing sufficient power serves to decrease the commission of Type II errors, and may prevent misinterpretations of nonsignificant results. Including statistical power in the design and analysis of an experiment requires an a priori estimate of the effect size, as well as calculating obtained effect size. The obtained effect size reflects the relationship between the independent and dependent variables, and as such provides a better characterization of the research effort than does reporting only the significance level.