A Note on Accounting for Sources of Variation in Perceptual Maps

1982 ◽  
Vol 19 (3) ◽  
pp. 302 ◽  
Author(s):  
William R. Dillon ◽  
Donald G. Frederick ◽  
Vanchai Tangpanichdee
1982 ◽  
Vol 19 (3) ◽  
pp. 302-311 ◽  
Author(s):  
William R. Dillon ◽  
Donald G. Frederick ◽  
Vanchai Tangpanichdee

Recently interest has centered on extending decompositional methods for modeling consumer preferences to include group-level effects. The motivation for this effort is the general belief that respondent background characteristics and situation variables frequently interact with product attributes in jointly influencing preferences over a set of multiattribute alternatives. In much the same way, respondent and situation factors can interact with product attribute perceptions in perceptual mapping applications to influence the respondent's ratings of the brands. The authors describe how respondent background characteristics and situation variables can be accounted for as sources of variation which can potentially influence the reduced space configuration of brands. Essentially the approach can be viewed as chaining multivariate analysis of variance and standard perceptual mapping techniques. Two illustrative examples are provided. In one example the results show that the uncovered spatial configuration of brands was influenced not only by the perceptual differences between the brands, but also by a respondent-related factor.


2010 ◽  
Vol 24 (3) ◽  
pp. 161-172 ◽  
Author(s):  
Edmund Wascher ◽  
C. Beste

Spatial selection of relevant information has been proposed to reflect an emergent feature of stimulus processing within an integrated network of perceptual areas. Stimulus-based and intention-based sources of information might converge in a common stage when spatial maps are generated. This approach appears to be inconsistent with the assumption of distinct mechanisms for stimulus-driven and top-down controlled attention. In two experiments, the common ground of stimulus-driven and intention-based attention was tested by means of event-related potentials (ERPs) in the human EEG. In both experiments, the processing of a single transient was compared to the selection of a physically comparable stimulus among distractors. While single transients evoked a spatially sensitive N1, the extraction of relevant information out of a more complex display was reflected in an N2pc. The high similarity of the spatial portion of these two components (Experiment 1), and the replication of this finding for the vertical axis (Experiment 2) indicate that these two ERP components might both reflect the spatial representation of relevant information as derived from the organization of perceptual maps, just at different points in time.


1951 ◽  
Vol 10 (4) ◽  
pp. 797-806 ◽  
Author(s):  
W. C. Rollins ◽  
C. E. Howell

2018 ◽  
Author(s):  
Charlotte A. Hudson ◽  
Liam Satchell ◽  
Nicole M Adams-Quackenbush

Purpose: Investigative interviews are complex, dyadic, activities typically studied by focusing on developing techniques to improve witness performance. However, in field settings, interviewers are known to vary in their presentation of good interviewing practice. Thus, it is important to conduct research reflective of complex idiosyncrasies in witnesses, interviewers and unique pairings of both. This study explores such sources of variation in an by making use of a 'round-robin' design. Such methodology allows the statistical demonstration of individual difference and unique partner-generated variance in interview performance. Methods: In our study, a total of 45 witnesses were questioned about five real crime videos. After witnessing each event, witnesses were interviewed by a different interviewer (or a computer self-administered interview). In total, nine 'rounds' of interviews occurred, with five new witnesses being interviewed in the same five interview settings (resulting in 225 interviews). After each interview both interviewers and witnesses were asked to complete subjective interview experience ratings. The quality (grain size) and quantity of information in the statements was coded to index witness report accuracy. Results: Principally, the results demonstrate the degree to which witnesses and interviewers affect statement quality, and highlight the influence of unique interviewer-witness pairs. (Participant personality and interviewer behaviour were also analysed, but with limited effects). Conclusion: This study presents the useful round-robin methodology for studying interviewer-witness behaviour. Whilst the current personality and behavioural measures do not account for these individual differences, we advocate this methodology be adopted more widely to better understand interview performance.


Author(s):  
Elin Haugsgjerd Allern ◽  
Tània Verge

How parties structure their interaction with social groups is a key determinant of their capacity to provide linkage between the institutions of government and the public at large. This chapter investigates the extent to which modern political parties use formal measures to connect to relevant societal interests and strengthen their anchorage in society. The analysis centres on parties’ use of formal rules governing affiliation and representation to link with externally organized interests and parties’ establishment of sub-organizations with representation rights within the party. The chapter authors develop and test several hypotheses concerning cross-country and within-country sources of variation in formal linkage and test them empirically. In addition, they examine whether formal status and representation rights shape parties’ ability to represent descriptively the associated latent social interests focusing on the case of women and ethnic minorities.


Author(s):  
Gustav Hultgren ◽  
Mansoor Khurshid ◽  
Peter Haglund ◽  
Zuheir Barsoum

AbstractA round-robin study has been carried out within a national project in Sweden with the addition of an international participant, where several industrial partners and universities are participating. The project aims to identify variation and sources of variation in welding production, map scatter in fatigue life estimation, and define and develop concepts to reduce these, in all steps of product development. The participating organisations were asked to carry out fatigue life assessment of welded box structures, which is a component in load-carrying structures. The estimations of fatigue life have also been compared with fatigue test results. Detailed drawings, loads and material data were also given to the participants. The participants were supposed to use assessment methods based on global and local stresses using the design codes or recommendations they currently use in-house. Differences were identified between both methods and participants using the same codes/recommendations. Applicability and conditions from the cases in the codes were also identified to be differently evaluated between the participants. It could be concluded that for the applied cases the nominal stress method often overestimated the fatigue life and had a high scatter in the estimations by different participants. The effective notch method is conservative in comparison to the life of tested components with little scatter between the results derived by the participants.


Author(s):  
Jarrad Gollihue ◽  
Victoria G. Pook ◽  
Seth DeBolt
Keyword(s):  

2020 ◽  
Vol 58 (8) ◽  
pp. 1302-1313 ◽  
Author(s):  
Anwar Borai ◽  
Kiyoshi Ichihara ◽  
Abdulaziz Masaud ◽  
Waleed Tamimi ◽  
Suhad Bahijri ◽  
...  

AbstractBackgroundThis is a second part of report on the IFCC global multicenter study conducted in Saudi Arabia to derive reference intervals (RIs) for 20 immunoassay analytes including five tumor makers, five reproductive, seven other hormones and three vitamins.MethodsA total of 826 apparently healthy individuals aged ≥18 years were recruited in three clinical laboratories located in western, central and eastern Saudi Arabia using the protocol specified for the global study. All serum specimens were measured using Abbott, Architect analyzers. Multiple regression analysis (MRA) was performed to explore sources of variation of each analyte: age, body mass index (BMI), physical exercise and smoking. The magnitude of variation of reference values (RVs) attributable to sex, age and region was calculated by ANOVA as a standard deviation ratio (SDR). RIs were derived by the parametric (P) method.ResultsMRA revealed that region, smoking and exercise were not relevant sources of variation for any analyte. Based on SDR and actual between-sex differences in upper limits (ULs), we chose to partition RIs by sex for all analytes except for α-fetoprotein and parathyroid hormone (PTH). Age-specific RIs were required in females for ferritin, estradiol, progesterone, testosterone, follitropin, luteotropin and prolactin (PRL). With prominent BMI-related increase, RIs for insulin and C-peptide were derived after excluding individuals with BMI > 32 kg/m2. Individuals taking vitamin D supplements were excluded in deriving RIs for vitamin D and PTH.ConclusionsRIs of major immunoassay analytes specific for Saudi Arabians were established in careful consideration of various biological sources of variation.


Author(s):  
Mona Roxana Botezatu ◽  
Taomei Guo ◽  
Judith F. Kroll ◽  
Sarah Peterson ◽  
Dalia L. Garcia

Abstract We evaluated external and internal sources of variation in second language (L2) and native language (L1) proficiency among college students. One hundred and twelve native-English L2 learners completed measures of L1 and L2 speaking proficiency, working memory, and cognitive control and provided self-ratings of language exposure and use. When considering learner-external variation, we found that more frequent L2 exposure predicted higher L2 and L1 proficiency, while earlier L2 exposure predicted higher L2 proficiency, but poorer L1 maintenance. L1–L2 distance limited crosslinguistic transfer of print-to-sound mappings. When considering learner-internal variation, we found that L1 and L2 proficiency were highly correlated and that better working memory, but not cognitive control, accounted for additional variance in L2 and L1 proficiency. More frequent L2 exposure was associated with better cognitive control.


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