Hypothesis correctness

In total for seaweeds, it appears that the CNB hypothesis correctly predicted the responses of phlorotannins (three of three species157-181 184), but not of terpenes (zero of two species181185). Similarly, terrestrial ecologists have also found that the CNB hypothesis appears to predict the responses of phenolic compounds better than for other C-based secondary metabolites.176 177... 

Reject nuU hypothesis Correct action Type I error (false positive)... 

Calculated values of it are provided in Table 13.13. Is the third order reaction hypothesis correct No Trend Accept the hypothesis that n = 3. 

The scientific method is taught starting in elementary school. The first step in the scientific method is to form a hypothesis. A hypothesis is just an educated guess or logical conclusion from known facts. It is then compared against all available data and its details developed. If the hypothesis is found to be consistent with known facts, it is called a theory and usually published. The characteristics most theories have in common are that they explain observed phenomena, predict the results of future experiments, and can be presented in mathematical form. When a theory is found to be always correct for many years, it is eventually referred to as a scientific law. However useful this process is, we often use constructs that do not fit in the scientific method scheme as it is typically described. 

It IS worth remembering that a theory can never be proven correct It can only be proven incor rect incomplete or inadequate Thus theories are always being tested and refined As important as anything else in the scientific method is the testable hypothesis Once a theory is proposed experiments are designed to test its validity If the results are con sistent with the theory our belief in its soundness is strengthened If the results conflict with it the theory IS flawed and must be modified Section 6 7 describes some observations that support the theory that car bocations are intermediates in the addition of hydro gen halides to alkenes... 

To test the null hypothesis, you reach into your pocket, retrieve a penny, and determine its mass. If the mass of this penny is 2.512 g, then you have proved that the null hypothesis is incorrect. Finding that the mass of your penny is 3.162 g, however, does not prove that the null hypothesis is correct because the mass of the next penny you sample might fall outside the limits set by the null hypothesis. 

If evidence for a determinate error is found, as in Example 4.16, its source should be identified and corrected before analyzing additional samples. Failing to reject the null hypothesis, however, does not imply that the method is accurate, but only indicates that there is insufficient evidence to prove the method inaccurate at the stated confidence level. 

Consider the hypothesis Ii = [Lo- If, iri fact, the hypothesis is correct, i.e., Ii = [Lo (under the condition Of = o ), then the sampling distribution of x — x is predictable through the t distribution. The obseiwed sample values then can be compared with the corresponding t distribution. If the sample values are reasonably close (as reflectedthrough the Ot level), that is, X andxg are not Too different from each other on the basis of the t distribution, the null hypothesis would be accepted. Conversely, if they deviate from each other too much and the deviation is therefore not ascribable to chance, the conjecture would be questioned and the null hypothesis rejected. 

The iV-nitroso compounds are carcinogenic, so the reaction could result in stomach cancer. This mechanism is essentially a hypothetical one, and tests were made to evaluate it. Three tests in particular suggested that the hypothesis was not correct, that is, that there is no clear link between stomach cancer and nitrate in water. 

The apparent cause(s) of the complaint(s) is (are) identified Remedial action and follow-up evaluation will confirm whether the hypothesis is correct. 

As originally proposed, the Zucker-Hammett hypothesis states that for A1 reactions log kobs is linear in —Ho, whereas for A2 reactions log kobs is linear in log ch+. This latter statement is now known not to be generally correct. Moreover, the slopes of plots against —Ho often differ from unity. Bunnett and Olsen... 

Fredkin points out that even if a preferred frame, or underlying lattice, is found, its implications are in one sense only philosophical the integrity of the theory of relativity remains intact, it is only our philosophical perspective that changes. Similarly, if a deterministic RUCA-like rule is the basis of the real physics, it does not mean that we should all throw away our quantum mechanics texts. On the other, if the finite nature hypothesis is correct and a RUCA-like rule exists and can be found, it should in principle be able to supply us with values of all of the fundamental constants of physics. 

Paper nine is another one that appeared in American Scientist. In it I took a philosophical look at two important ideas that contributed to the evolution of the periodic system. These two ideas are Prout s hypothesis and the notion of triads, which was the subject of paper eight. Both hypotheses are interesting because they were extremely productive even though they both turned out to be refuted some time later. The fact that this should happen lends some support to the views of Karl Popper who always claimed that refutability was the all important aspect of good hypotheses and theories and not whether they turn out to be correct or not.23 For Popper, all that we really have is tentative theories and not theories that last forever. 

A substantial amount of indirect evidence supports the contention that the induction of apoptosis in tumor cells is critical to successful therapy. Cancer therapy might therefore be viewed as an attempt to induce apoptosis in a population of cells that have undergone selection for apoptotic defects. If correct, this hypothesis would suggest why cancer therapy is in many cases unsuccessful. However, recent studies indicate that this fundamental problem can be circumvented. Progress in the identification of molecules key to the cell death pathways has led to a growing understanding of how apoptosis occurs [3]. It has become clear that pathways to apoptosis are numerous and often interconnected. A solution to the clinical problem of therapeutic resistance, then, may lie in the fact that there appears to be multiple ways that a cell death program can be implemented. 

Hence, for a given P, G and Ah, the hypothesis will be correct if two tubes of different length, but with the same Ljd ratio, give the same burn-out flux. Barnett (B3) has tested Eq. (2), and Fig. 21 gives one of his test results, showing that the hypothesis is not generally valid. Thus, any burn-out theory or correlation which combines L and d only as a ratio cannot generally be correct. 

It can be seen that k in Eq. (10) replaces the system-describing parameters L and Ah in Eq. (1). A direct test of the hypothesis is therefore to plot (j> against k for fixed values of P, G, and d, with L and Ah varying. For the hypothesis to be correct, the data points must all lie on a smooth curve. Experience shows, however, that plotting (f> against k often produces an undue amount of scatter which may obscure and distort any true relationship existing. This enhanced scatter is caused by the cumulative effect of experimental errors in the various terms in the heat-balance equation from which the quality k is derived. 

That the total-power hypothesis cannot be correct, however, is well shown from an experiment reported by Lee and Obertelli (L5). In this experiment, a symmetrical-cosine heated tube of 0.383-in. diameter and 72-in. length was... 

In Section 8.3 the mechanism of heterolytic dediazoniation of arenediazonium ions was discussed, and it was shown that the hypothesis of Crossley et al. (1940) that the aryl cation is the characteristic metastable intermediate in those reactions was not consistent with some experimental facts found in 1952 by Lewis and Hinds. Nevertheless, these facts did not have significant influence on the scientific community, which continued to accept the original and apparently convincing hypothesis of the rate-limiting formation of an aryl cation as an intermediate as correct . The incom-patabilities of various mechanistic hypotheses with experimental facts were, however, discussed in some detail only two decades later (Zollinger, 1973 a). Another year passed before I performed a crucial experiment that refuted a number of hypotheses (Bergstrom et al., 1974, 1976). ... 

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