Discomfort glare evaluation: the influence of anchor bias in luminance adjustments

Luminance adjustment is a procedure commonly used to evaluate discomfort glare and the results from adjustment experiments form the basis of some recommendations for limiting its occurrence. There are, however, strong reasons to expect that settings made using adjustment are unintentionally influenced by extraneous variables. This paper discusses bias towards the initial anchor, the setting of the variable stimulus immediately before an adjustment is made. Specifically, the initial luminance is expected to influence the setting that is made by adjustment; for example, a lower initial luminance leads to a lower setting than a high initial luminance. To investigate anchor bias, a Hopkinson-like multiple-criterion adjustment experiment was undertaken, but with three different anchors. The results confirmed significant bias: glare settings were biased towards the luminance of the initial anchor. This demonstrates a need for caution when using adjustment to explore discomfort glare and when interpreting the results of past studies that used discomfort glare models fitted to data obtained with this procedure

Apicomplexan protozoa responsible for reproductive disorders: Occurrence of dna in blood and milk of donkeys (equus asinus) and minireview of the related literature

Donkeys may be susceptible to many pathological agents and may act as carriers of pathogens for other animal species and humans. This study evaluated the occurrence of potentially abortifacient apicomplexan protozoa DNA in blood and milk samples collected at different time periods during lactation (1, 6, and 10 months) from 33 healthy dairy jennies. A total of 73 blood and 73 milk samples were used for DNA extraction and analysis. Blood specimens from 11/33 (33%) jennies scored positive for Theileria equi, while milk samples scored negative. Blood and milk of 3/33 jennies yielded DNA of Toxoplasma gondii at 6 months (n. 1) and 10 months (n. 2) after parturition. Neospora caninum DNA was found in four milk and in five blood samples only at one month after parturition. This study is the first report about the presence of N. caninum DNA in milk of naturally infected jennies. Moreover, the excretion of N. caninum DNA in some of these jennies at 30 days from the parturition may suggest a possible occurrence of an endogenous cycle, while the presence of T. gondii DNA in the milk collected at 6 and 10 months after parturition may be suggestive of a discontinuous excretion

Effects of bread in the diet of fattening pigs reared extensively

We evaluated the effects of adding unsold bread (i.e. a low-cost product) to the diet of fattening crossbreed pigs reared outdoors. A total of 27 Goland sows were allocated to three homogeneous groups and fed with different diets: A feed + 15% bread; B feed + 30% bread; C the control group (only feed). The pigs were weighed individually on arrival at the farm, at the start of the experiment, and at slaughter. Growth performance and carcass traits were evaluated. Two sections from the loin were taken from each animal and the following were analyzed: dry matter, crude protein, lipids, ash, fatty acids, pH, color, water-holding capacity, and lipid oxidation. Group B had higher gains and slaughter weights than group C, while group A showed intermediate values. The results show that a diet containing 30% bread facilitates weight gain of pigs, without affecting meat quality and nutritional value

Order effects when using Hopkinson’s multiple criterion scale of discomfort due to glare

Hopkinson’s multiple criterion scale is widely used to investigate the subjective degree of discomfort due to glare. Using an adjustment procedure, glare source luminance is adjusted to reveal four levels of discomfort, typically: just imperceptible, just acceptable, just uncomfortable, and just intolerable. In many studies, observers are instructed to attend to each level of discomfort in ascending order, from the lowest to the highest criterion. It is likely, however, that any settings made using this approach are influenced by an order bias, and this would affect the reported thresholds of discomfort. To investigate order effects, a Hopkinson-like multiple criterion adjustment experiment was performed, but under three different order sequences: ascending, descending, and randomised. The results revealed substantial bias due to order effects, particularly for lower glare criteria. This demonstrates the need for caution when interpreting subjective evaluations of discomfort due to glare and estimating the robustness of glare indices derived from studies that used Hopkinson’s scale and procedure

Discomfort glare evaluation: the influence of anchor bias in luminance adjustments

Luminance adjustment is a procedure commonly used to evaluate discomfort glare and the results from adjustment experiments form the basis of some recommendations for limiting its occurrence. There are, however, strong reasons to expect that settings made using adjustment are unintentionally influenced by extraneous variables. This paper discusses bias towards the initial anchor, the setting of the variable stimulus immediately before an adjustment is made. Specifically, the initial luminance is expected to influence the setting that is made by adjustment; for example, a lower initial luminance leads to a lower setting than a high initial luminance. To investigate anchor bias, a Hopkinson-like multiple-criterion adjustment experiment was undertaken, but with three different anchors. The results confirmed significant bias: glare settings were biased towards the luminance of the initial anchor. This demonstrates a need for caution when using adjustment to explore discomfort glare and when interpreting the results of past studies that used discomfort glare models fitted to data obtained with this procedure

A Bayesian method of evaluating discomfort due to glare: the effect of order bias from a large glare source

Replicating scientific findings is a fundamental aspect of research. However, in studies of discomfort due to glare, it is difficult to make comparisons between the results of different experiments since the statistical tests usually reported do not allow independent findings to be directly compared to each other. Here we present an alternative Bayesian approach that can address this problem. To show how this approach works, we performed a laboratory test with 55 participants to validate the effect of order bias previously detected in a similar study evaluating discomfort due to glare but, this time, under a large luminous source. Using the luminance adjustment procedure, the glare source was varied to meet four sensations of discomfort due to glare. Adjustments were performed under three different order sequences: ascending, descending, and randomised. Test participants provided glare settings using a newly proposed evaluation scale. The effect of order bias detected in the original study was compared to the data obtained with the same methodological procedure in the new experiment using Bayesian inferential tests. The results showed a close replication, highlighting that the order bias effect found in the original study was also present in the new experiment. The wide application of Bayesian methods in the design and analysis of experimental studies may improve the accuracy and validity of glare models

Order effects when using Hopkinson’s multiple criterion scale of discomfort due to glare

Hopkinson’s multiple criterion scale is widely used to investigate the subjective degree of discomfort due to glare. Using an adjustment procedure, glare source luminance is adjusted to reveal four levels of discomfort, typically: just imperceptible, just acceptable, just uncomfortable, and just intolerable. In many studies, observers are instructed to attend to each level of discomfort in ascending order, from the lowest to the highest criterion. It is likely, however, that any settings made using this approach are influenced by an order bias, and this would affect the reported thresholds of discomfort. To investigate order effects, a Hopkinson-like multiple criterion adjustment experiment was performed, but under three different order sequences: ascending, descending, and randomised. The results revealed substantial bias due to order effects, particularly for lower glare criteria. This demonstrates the need for caution when interpreting subjective evaluations of discomfort due to glare and estimating the robustness of glare indices derived from studies that used Hopkinson’s scale and procedure