The role of factors previously implicated as leading to confirmation bias during hypothesis testing was explored. Confirmation bias is a phenomenon in which people select cases for testing when the expected results of the case are more likely to support their current belief than falsify it. Klayman (1995) proposed three primary determinants for confirmation bias. Klayman and his colleagues proposed that a general positive testing strategy leads to the phenomenon of confirmation bias. According to Klayman’s account, participants in previous research were not actively working to support their hypothesis. Rather, they were applying a valid hypothesis testing strategy that works well outside of laboratory tasks. In laboratory tasks, such as Wason’s 2-4-6 task (Wason, 1960), the strategy failed because the nature of the task takes advantage of particular flaws in the positive testing behavior participants learned through their experience with the real-world. Given Klayman’s proposed set of determinants for the positive testing strategy phenomenon, treatments were developed that would directly violate the assumptions supporting application of the positive testing strategy. If participants were able to identify and act on these violations of the assumptions, the number of positive tests was expected to be reduced. The test selection portion of the Mynatt, Doherty, and Tweney (1977) microworld experiment was modified with additional instruction conditions and a new scenario description to investigate the impact of the treatments to reduce confirmation bias in test selection. Despite expectations, the thematic content modifications and determinant-targeting instruction conditions had no effect on participant positive test selection.

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<p>A large section of the industrial organization literature is devoted to the interpretation and empirical testing of the hypotheses advanced by Joseph Schumpeter concerning market structure and innovation. One set of hypotheses deals with the monopoly power of firms and its association with innovation, while the other set focuses on the relationship between firm size and innovation. Empirically these two sets of hypotheses may not be independent of each other, although extant empirical studies have concentrated on one in isolation of the other. In this dissertation we build a general framework where these two sets of hypotheses can be considered together in order that we can properly identify either effect -- that is, the effects of monopoly power and of firm size on innovation.</p> <p>A major objective of our study is to combine two recent developments in the literature. First, it has been empirically demonstrated that proxies for appropriability and technological opportunity, when included in the regression, significantly diminish the explanatory power of concentration (a measure of monopoly power) on innovation and lnnovation-related activities, such as Research and Development (R&D) expenditures. In this dissertation, we construct sever,d proxies for appropriability and technological opportunity, using new data on innovative activities of firms in Canada collected by the Economic Council of Canada.</p> <p>Second, it has been recently argued that, except in the short run, both market structure and innovative activities ought to be treated as endogeneous, as opposed to the existing practice of assuming that the market structure is given. Our theoretical framework allows both innovative activity and firm size (a measure of market structure) to be determined by appropriability, technological opportunity and various non-innovative factors such as demand conditions, foreign versus domestic ownership of firms, etc.</p> <p>It is commonly observed that firms sometimes choose not to hire any R&D personnel, namely, scientists and engineers, and instead entrust the responsibilities of R&D either with a consulting firm or even with its own operating personnel. These decisions result in observations with 'zero' values for R&D personnel in the sample. In this dissertation, we provide an economic underpinning for such decisions by firms and recognize this 'limited-dependent variable' problem in our estimation through use of the Tobit estimation method.</p> <p>Finally, as a by-product of our theoretical framework we examine some of the common empirical measures which have been used to test the Schumpeterian hypotheses. One of our major findings in this regard is that many of the existing empirical tests of the hypothesis that there is a positive externality from firm size to innovative activities of firms are misspecified in the sense that they are neither necessary nor sufficient for the existence of the above externality.</p> / Doctor of Philosophy (PhD)

To test the hypothesis that postprandial rises of plasma glucose attenuate the motivation derived from positive tastes, I analyzed the effects of intraperitoneal (ip) injections of glucose on sham feeding, a preparation in which food intake is motivated primarily by taste sensations. IP glucose suppressed sham feeding, with maximal suppressions approximating 42%, but only when glucose was administered contiguous with oropharyngeal stimulation. The food intake inhibition produced by ip glucose interacted with palatability; smaller doses of glucose were required to suppress less concentrated sucrose solutions. Closing the gastric cannula increased the potency with which ip glucose inhibited eating suggesting synergy of postabsorptive glucose with other postgastric satiety signals. The inhibition of eating produced by ip glucose did not result from malaise. Thus, postabsorptive rises of plasma glucose decrease the ability of taste cues to drive ingestion and suggest that this phenomenon may contribute to spontaneous meal termination. / Thesis / Master of Science (MSc)

In Experiment 1, the degree of belief in a focal hypothesis was manipulated using priming as well as the principle of unpacking of Tversky and Koehler (1994). The effects of these manipulations on feature detection was measured. It was found that regardless of the degree of belief in the focal hypothesis, novice diagnosticians who have it in mind will call more of its features than those who do not have it in mind. It is believed that this is due to the fact that having a diagnosis in mind seems to focus the attention of diagnosticians to the relevant features. Also, our manipulation of suggesting alternatives to the diagnosticians did not have the effect of decreasing the diagnosticians' belief in the focal hypothesis, contrary to what is predicted by Tversky and Koehler's unpacking principle (1994). The results from Experiment 1 suggest, and those from Experiment 2 confirm the hypothesis that in order to decrease the degree of belief in the focal hypothesis when it is presented with alternatives, the alternatives must be plausible. If the focal hypothesis is extremely dominant over the alternatives, a reversal of the unpacking principle will occur. / Thesis / Master of Science (MS)