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Question Formats (question + formats)
Selected AbstractsEffect of Two Types of Control Questions and Two Question Formats on the Outcomes of Polygraph Examinations,JOURNAL OF FORENSIC SCIENCES, Issue 4 2008Frank Horvath Ph.D. Abstract:, Two major variations of polygraph "Control Question" testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated. Within each, the type of control question, Exclusive or "time bar" (e.g., "Before you were 21, did you ever...") and Nonexclusive or "no time bar"(e.g., "Did you ever,.?") was manipulated in a mock theft scenario, with 80 male and 40 female subjects randomly assigned to be either innocent or guilty. Polygraphic data collected by experienced field examiners were numerically scored by an evaluator blind to all aspects of the study. Decision accuracy was not related to the type of procedure (ZoC/MGQT) used or the subject's sex. Accuracy was significantly related to the type of control question [,2(2) = 11.46, p = 0.003; ,c = 0.29]. Nonexclusive control questions produced greater accuracy than Exclusive control questions on both innocent and guilty subjects. These results and subjects' self-reports support the general "theory" on which control question (CQ) testing is based. The need for better empirical support of accepted dogma and current field practices is strongly indicated by these findings. [source] Inter-rater and test,retest reliability of three contingent valuation question formats in south-east NigeriaHEALTH ECONOMICS, Issue 5 2005Obinna Onwujekwe Abstract This paper examines the inter-rater and test,retest reliability of willingness to pay (WTP) for insecticide-treated mosquito nets and net re-treatment using the bidding game (BG), binary with follow-up (BWFU) and a novel structured haggling technique (SH). Inter-rater reliability was evaluated by having two sets of interviewers administer questionnaires to 109 (BG), 110 (BWFU) and 103 (SH) randomly selected household heads. Test,retest reliability was investigated by repeating interviews on 146 (BG), 161 (BWFU) and 139 (SH) household heads one month after an initial survey. Data analysis used testing of means, Spearman's correlation and Pearson's correlation coefficient for test of reliability, while non-parametric analysis was used to determine factors causing a variation in WTP. The study was conducted in Southeast Nigeria. Inter-rater reliability coefficients were estimated for the individual's WTP for own nets, WTP for others and WTP for re-treatment. Using WTP for own nets as the best reliability estimate, the coefficients were high at values of 0.77 (C.I. 0.72,0.86), 0.75 (C.I. 0.64,0.81) and 0.74 (C.I. 0.63,0.82) in the BG, BWFU and SH, respectively. In test,retest reliability coefficients, the coefficients for WTP for own nets were low-to-moderate at values of 0.51 (C.I. 0.40,0.62), 0.41 (C.I. 0.28,0.53) and 0.56 (C.I. 0.41,0.65) for the BG, BWFU and SH groups, respectively. Factors such as gender, change in income, unplanned expenditures, stated WTP in first survey, time-to-think, external information, and subjecting respondents to more than one interview explained the lower test,retest reliability coefficients. We conclude that the CVM was reliable in the study area and the question formats had similar levels of reliability. The lower coefficients in the test,retest reliability were due to the influence of factors affecting demand that had changed in the intervening period. Standard formats for determining reliability within CVM should be developed for easy comparison of results from different studies. Copyright © 2004 John Wiley & Sons, Ltd. [source] Willingness to pay for a hearing aid: comparing the payment scale and open-ended questionJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 1 2009Janneke P. C. Grutters MSc Abstract Rationale & objectives, Different question formats elicit different willingness-to-pay (WTP) results, but there is no consensus on which method elicits the most valid WTP. In spite of the methodological controversies, WTP is a potentially valuable tool in health economics to value health services. Our general objective was to provide additional evidence on the validity of two WTP elicitation formats: the open-ended question and the payment scale. Methods, We elicited WTP for a hearing aid among hearing aid users (n = 108), using both a payment scale and an open-ended question. We compared the results from both formats. We tested criterion validity by comparing both formats with the actual out-of-pocket payment. Construct validity was tested by examining whether WTP was consistent with positive income elasticity. Results, The WTP results elicited with the payment scale and open-ended question were not statistically significantly different. Both formats showed good criterion validity, although the open-ended question showed a stronger association with the actual out-of-pocket payment. The open-ended format showed better construct validity, as it was influenced by family income. Conclusion, The results of the present study showed that the open-ended question was more valid than the payment scale question. We, therefore, recommend that in future WTP studies on hearing aids the open-ended question is used to directly elicit WTP values. The same recommendation may apply to other studies where respondents are familiar with costs or payments for the intervention under evaluation. [source] | ||||||||||