Blind examination

In theory, all microscopic evaluations should be performed blind (without the pathologist knowing from which dose group a particular animal came), but this is difficult to do in practice and such an approach frequently degrades the quality of the evaluation. Like all the other portions of data in the study, proper evaluation benefits from having access to all data that addresses the relevance, severity, timing, and potential mechanisms of a specific toxicity. Blind examination is best applied in peer review or consultations on specific findings. 

Although the guideline states that evaluation of the dams during caesarean section and subsequent fetal analyses should be conducted preferably without knowledge of treatment group in order to minimise bias (4), the value of such a blinded examination according to our experience is more than limited. 

It is generally agreed that blind examination of fetuses is an unnecessary source of error for regulatory studies. No explanation is given why the FDA considers this precaution to be necessary for food additives, but not for pharmaceuticals (10). 

If an optimization tuns out of steps, do not blindly assume that increasing the number of steps will fix the problem. Examine the output and determine whether the optimization was making progress or not. For example this command will provide a quick summary of an optimization s progress on a UNIX system (blank lines ate added for readability) ... 

Hill, H. Z. (1992). The function of melanin or six blind people examine an elephant. BioEssays 14 49-56. 

Babyak, Michael A., James A. Blumenthal, Steve Herman, Parinda Khatri, P. Murali Doraiswamy, Kathleen A. Moore, W. Edward Craighead, Teri T. Baldewicz and K. Ranga Krishnan, Exercise Treatment for Major Depression Maintenance of Therapeutic Benefit at 10 Months , Psychosomatic Medicine 62 (2000) 633-38 Barbui, Corrado, Andrea Cipriani and Irving Kirsch, Is the Paroxetine-Placebo Efficacy Separation Mediated by Adverse Events A Systematic Re-Examination of Randomised Double-Blind Studies , submitted for publication (2009)... 

I know of no experienced practitioner of chemometrics who would blindly use the full spectrum when applying PLS or PCR. In the book Chemometrics by Beebe, Pell and Seasholtz, the first step they suggest is to examine the data. Likewise, Kramer in his new book has two essential conditions The data must have information content and the information in the data must have some relationship with the property or properties which we are trying to predict. Likewise, in the course I teach at Union Carbide, I begin by saying that no modeling technique, no matter how complex, can produce good predictions from bad data. ... 

Blind samples are types of sample which are inserted into the analytical batch without the knowledge of the analyst - the analyst may be aware that blind samples are present but not know which they are. Blind samples may be sent by the customer as a check on the laboratory or by laboratory management as a check on a particular system. Results from blind samples are treated in the same way as repeat samples - the customer or laboratory manager examines the sets of results to determine whether the level of variation, between repeat measurements on the blind sample or between the observed results and an expected value, is acceptable, as described in Section 5.4.3. 

Examinations of the color sense in G-6-PDH deficient individuals showed a fairly close linkage between the gene loci determining color blindness and enzyme deficiency (A2). 

The effects of kavain on human electrophysiology was examined in a double-blind, placebo-controlled study (Frey 1991). Dose-dependent increases were seen in delta, theta, and alpha 1 power, and decreases ocurred in alpha 2 and beta power. These changes were suggestive of a sedative effect of kavain, and were maximal in frontal areas. Interestingly, an initial activating effect was seen at the lowest dose (200 mg) but not at the largest dose (600 mg). 

Pharmaceutical Comparison. At least 8 studies to date have examined the effectiveness of hypericum compared to the pharmaceutical antidepressants imipramine, amitriptyline, and maprotiline. Preliminary results indicate that hypericum is equivalent to standard antidepressants in effectiveness (Linde et al. 1996 Vorbach 1997). Similar to the pharmaceutical antidepressants, there is a 10-14 day lag for therapeutic effects of hypericum (Harrer et al. 1994). Indeed, the differences seen between hypericum and placebo groups becomes apparent between 2 and 4 weeks (Sommer and Harrer 1994). Hypericum has been reported to have a more favorable side-effect profile than several pharmaceutical antidepressants as well (Vorbach et al. 1994 Harrer et al. 1994). In double-blind studies, subjects have reported fewer and less-severe side effects. Although these initial results are promising, Linde and colleagues (1996) have concluded that the present evidence is inadequate to establish... 

Hansgen KD, Vesper J, Ploch M. (1994). Multicenter double-blind study examining the antidepressant effectiveness of the hypericum extract LI 160. J Geriatr Psychiatry Neurol. 7(suppl 1) S15-8. 

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