Empirical evidence

If one compares the monohemispheric auditory and visual reaction tasks of one subject with another, one sees that the auditory tasks need more time to be done. This is also seen in the computed cycle numbers in a22y the auditory cycle numbers are 1-2 cycles higher than in v22y and in a33y the cycle numbers are even 3-5 cycles higher than in v33y (see tables above). 

An important hint is the recurrence of the number 4 in the directly observed cycle numbers of tasks a22y. This proposes that in these tasks the number of four searching actions plays an essential role. There is an interval between ally and the first peak in the distribution of a22y (daCN-method). Is there any process in this interval which does not produce a peak. The analogous visual tasks do not show this interval. Here the peaks of wily start shortly after vlly reaction time. 

There could be some other cycles in a22y which are important. These cycles are the minimal necessary cycles to solve the task. There cannot exist trials with reaction times shorter or equal to them. 

This minimal number of cycles can be measured empirically and can be predicted by the above hypotheses. 

Comparison of the directly observed auditory and visual cycle times 

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For the air—water system, Lewis recognized that Cf = hg/ ky based on empirical evidence. Thus, the adiabatic saturation equation is identical to the wet-bulb temperature line. In general, again based on empirical evidence (21),... 

We will explore further the idea that there may be a relationship between rates and equilibria. Although such a relationship is not required by thermodynamics, neither is it forbidden, and much empirical evidence supports the frequent occurrence of such relationships. Chapter 7 is devoted to this topic here we restrict attention to correlations of AG (or log k) with AG° (or log K) of the same reaction. Such correlations are usually sought within a reaction series in which a set of reactants having a common reaction site but different substituent sites are subjected to the same reaction. 

The foregoing defined quantities interact according to the following fundamental laws, which are based upon empirical evidence. 

First it is surely important to emphasise (as Brush does not) that there turned out to be independent empirical evidence for the new values assigned to these atomic weights (this re-evaluation relied, of course, on already accepted auxiliary theories—atomic weights of elements are highly theory-laden facts). It was not that chemists simply came to accept the new values because those values made those elements fit Mendeleev s table better (that would be a classic case of an ad hoc accommodation). For example, the corrected value of the atomic weight of... 

Some of the empirical evidence, such as the small effect of changing from H to F, Cl, Br on one end and the apparently small effect on the barrier of bending the C—H bonds, would be understandable in terms of a noncylindrical C—C bond. Further, the crudity of available quantum mechanical methods may be such that this effect is perhaps still a possible one. However, there is one serious... 

The Additivity of the Energies of Normal Covalent Bonds. The Hydrogen Halides and the Halogen Halides.—It is found that there exists a convincing body of empirical evidence in support of the postulate6 that the energies of normal covalent bonds are additive that is... 

Our knowledge of the properties of orbitals indicates that some of the 3d orbitals might be combined with the 45 and 4p orbitals to form bond orbitals in metals, the other 3d orbitals being unsuited to bond formation, but does not suffice to give a theoretical derivation of the number of d orbitals in each of these classes. Empirical evidence, outlined below, indicates that about 2.44 d orbitals (on the average) show only weak interatomic interactions, and that the remaining 2.56 d orbitals combine with the 5 orbital and the p orbitals to form hybrid bond orbitals. 

It is our experience that to the first question, the most common student response is something akin to Because my teacher told me so . One is tempted to say that it is a pity that the scientific belief of so mat r students is sourced from an authority, rather than from empirical evidence - except that when chemists are asked question (ii), they find it not at all easy to answer. There is, after all, no single defining experiment that conclusively proves the claim, even though it was the phenomenon of Brownian motion that finally seems to have clinched the day for the atomists 150 or so years ago. Of course, from atomic forced microscopy (AFM), we see pictures of gold atoms being manipulated one by one - but the output from AFM is itself the result of application of interpretive models. 

The observation of the system NO2/N2O4 provided essential empirical evidence to support the idea that the reactant and product could coexist. According to the questions posed in the activity, this evidence could not only be made explicit in the representation of their models but also be explained by the models. The students who were able to establish relationships between the movement of molecules and the occurrence of a chemical reaction (according to the kinetic particle model that had been studied earlier), were also able to include dynamic components in their models. Those who were not able to do so had the opportunity to think about this from the general discussion of the models - when all groups presented and justified their ideas - or from other empirical evidence that was obtained next. 

The system CrO / Cx20 -, provided students with a new context within which to use the model previously created for the system NO2/N2O4. From this second system students (i) acquired additional evidence about the coexistence of reactants and products in a chemical reaction and (ii) could observe what happened when the equilibrium was changed. This last set of empirical evidence was included in the teaching activities specifically to support the testing of students previous models. 

In sum, the empirical evidence presented new information about the systems under study, prompting the creation of new expectations concerning the models previously built, and encouraging students to think about the applicabihty of both the model itself and its modes of representation. These considerations often resulted in a changing of the models in a way as to widen their scope of application to new contexts. 

The way that the teacher conducted the lessons contributed to making some details of the systems explicit and helped students in interpreting (i) the empirical evidence, (ii) the questions to be answered by the models, and (iii) the symbolic representations she presented for each system. Moreover, the teacher s questions supported the students as they tried to remember previous ideas and/or models, to identify the limitations of their models, to propose new models or new explanations for the use of their models in new contexts. Finally, the teachers questions were very helpful for increasing students confidence in their models. 

Barke, H. D. (1982). Students experiments with stractural models. Empirical evidence for the practical use of models in the introduction of chemical symbols (Schiilerversuche mit Struk-turmodellen. Empirische Untersuchungen zum praktischen Einsatz von Modellen bei der Einfuhrung von chemischen Symbolen). CU, 13, 4. 

Empirical evidence seems also to support the preference for AG. Ingold based all of the structure-reactivity discussions in his famous book on AG values and believed that this choice is in accord with overall experience, at least as long as very small differences are disregarded (22). Values of AG usually correlate better with quantum chemical indices (199) and with empirical reactivity... 

Abbreviations See Section 5.1. Deviations for z > 3.5 (CP < 0.0003 or CP > 0.9997) can be larger than 0.01, but this is irrelevant due to the low probability of having to simulate such a z-value since empirical evidence points toward wider-than-ND tails, this is actually a step in the right direction. 

Empirical evidence supporting the role of soil micro-layer losses in zero-time issues is given by the often-seen rise in post zero-time residue recoveries. The improved recoveries likely result from the micro-layer residue redistribution that reduces losses of the highly concentrated surface residues. There has been some speculation that zerotime core recoveries may be due to volatilization losses not measured by standard laboratory studies. If this were the case, however, increases in residue concentrations would not occur over time since volatilized residues would be lost to the atmosphere. ... 

The above analysis of Barbados corals also places constraints on the history of the marine value. Empirical evidence suggests that diagenesis generally acts to raise the value of Barbados fossil corals, which makes the lowest initial value for each terrace the best estimate of the marine value at the time the terrace was formed. This makes it possible to extend evidence for a stable marine value beyond the last... 

The point is that the practice of medicine should be based on empirical evidence, not on its absence. I do not have to prove that antidepressants do not work. Instead, it is the job of the drug companies to prove that they do work. If the trials were flawed, then clinically significant differences between antidepressant and placebo have not been established for most patients. If the trials were not flawed, the data indicate that clinically significant differences between antidepressant and placebo have not been established for most patients (quoted from the previous sentence). Either way, the objective of proving the effectiveness of antidepressant medication has not been met. 

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