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Background Assessment of habitual diet is important in investigations of diet-disease relationships. Many epidemiological studies use the food frequency questionnaire (FFQ) to evaluate dietary intakes but few studies validate the instrument against biological markers. The aim of this study was to assess the validity and reproducibility of a previously validated 70-item food frequency questionnaire (FFQ) that was expanded to 120-items to assess diet - cancer relations. Methods Relative validity of the FFQ was assessed against twelve 24-hour recalls administered over 12 months in 70 subjects. The FFQ was repeated after one year (FFQ2) to assess reproducibility. The validity of the FFQ was evaluated by comparing nutrient and food group intakes from 24-hour recalls with the first and second FFQ. In addition, FFQ validity for cholesterol and folate were determined through correlation with biomarkers (serum cholesterol, serum folate and whole blood folate) in 159 control subjects participating in a case-control prostate cancer study. Results Compared to recalls the FFQ tended to overestimate energy and carbohydrate intakes but gave no differences in intake for protein and fat. Quartile agreement for energy-adjusted nutrient intakes between FFQ2 and recalls ranged from 31.8% - 77.3% for the lowest quartile and 20.8% - 81.0% in the highest quartile. Gross misclassification of nutrients was low with the exceptions of protein, vitamin E and retinol and weighted kappa values ranged from 0.33 to 0.64 for other nutrients. Validity correlations for energy-adjusted nutrients (excluding retinol) were moderate to high (0.38- 0.86). Correlation coefficients between multiple recalls and FFQ1 ranged from 0.27 (fruits) to 0.55 (red meat); the second FFQ gave somewhat higher coefficients (0.30 to 0.61). Reproducibility correlations for the nutrients ranged from 0.50 to 0.84. Calibration of the FFQ with biochemical markers showed modest correlations with serum cholesterol (0.24), serum folate (0.25) and whole blood folate (0.33) adjusted for age, energy, body mass index and smoking. Conclusions The expanded FFQ had good relative validity for estimating food group and nutrient intakes (except retinol and vitamin E) and was a reliable measure of habitual intake. Associations with biomarkers were comparable to other studies.

According to the comparator process hypothesis (Matute, Arcediano, & Miller, 1996), cue competition in the learning of between-events relationships arises if the judgement required involves a comparison between the probability of the outcome given the target cue and the probability of the outcome given the competing cue. Alternatively, other associative accounts (the Rescorla-Wagner model: Rescorla & Wagner, 1972) conceive cue competition as a learning deficit affecting the target cue-outcome association. Consequently, the comparator process hypothesis predicts that cue competition occurs in inference judgements but not in contiguity ones, for only the first type of judgement implicitly involves such a comparison. On the other hand, the Rescorla-Wagner model predicts cue competition in both inference and contiguity judgements, because it establishes no relevant role for the type of judgement in producing cue competition. In Experiments 1 and 2 we manipulated the relative validity of cues and the type of question (inference vs. contiguity) in a predictive learning task. In both experiments we found a cue competition effect, but no interaction between the relative validity of cues and the type of question, suggesting that the Rescorla-Wagner theory suffices to explain cue competition.

Background: Diet and physical activity (PA) have a major impact on physical and mental health. However, there is a lack of effective strategies for sustaining these health-protective behaviors. A shift to a microtemporal, within-person approach is needed to capture dynamic processes underlying eating behavior and PA, as they change rapidly across minutes or hours and differ among individuals. However, a tool that captures these microtemporal, within-person processes in daily life is currently not present. Objective: The APPetite-mobile-app is developed for the ecological momentary assessment of microtemporal, within-person processes of complex dietary intake, objectively recorded PA, and related factors. This study aims to evaluate the feasibility and usability of the APPetite-mobile-app and the validity of the incorporated APPetite-food record. Methods: The APPetite-mobile-app captures dietary intake event-contingently through a food record, captures PA continuously through accelerometers, and captures related factors (eg, stress) signal-contingently through 8 prompts per day. Empirical data on feasibility (n=157), usability (n=84), and validity (n=44) were collected within the Eat2beNICE-APPetite-study. Feasibility and usability were examined in healthy participants and psychiatric patients. The relative validity of the APPetite-food record was assessed with a subgroup of healthy participants by using a counterbalanced crossover design. The reference method was a 24-hour recall. In addition, the energy intake was compared with the total energy expenditure estimated from accelerometry. Results: Good feasibility, with compliance rates above 80% for prompts and the accelerometer, as well as reasonable average response and recording durations (prompt: 2.04 min; food record per day: 17.66 min) and latencies (prompts: 3.16 min; food record: 58.35 min) were found. Usability was rated as moderate, with a score of 61.9 of 100 on the System Usability Scale. The evaluation of validity identified large differences in energy and macronutrient intake between the two methods at the group and individual levels. The APPetite-food record captured higher dietary intakes, indicating a lower level of underreporting, compared with the 24-hour recall. Energy intake was assessed fairly accurately by the APPetite-food record at the group level on 2 of 3 days when compared with total energy expenditure. The comparison with mean total energy expenditure (2417.8 kcal, SD 410) showed that the 24-hour recall (1909.2 kcal, SD 478.8) underestimated habitual energy intake to a larger degree than the APPetite-food record (2146.4 kcal, SD 574.5). Conclusions: The APPetite-mobile-app is a promising tool for capturing microtemporal, within-person processes of diet, PA, and related factors in real time or near real time and is, to the best of our knowledge, the first of its kind. First evidence supports the good feasibility and moderate usability of the APPetite-mobile-app and the validity of the APPetite-food record. Future findings in this context will build the foundation for the development of personalized lifestyle modification interventions, such as just-in-time adaptive interventions. Trial Registration

Background: The validation of dietary assessment instruments is critical in the evaluation of diet as a chronic disease risk factor. Objective: The objective was to assess the validity of a self-administered food-frequency questionnaire by comparison with dietary recall, urinary nitrogen excretion, and total energy expenditure data. Design: Over a 1-y period, data from twelve 24-h dietary recalls, a food-frequency questionnaire, and four 24-h urine samples were obtained from 134 study participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study in Potsdam, Germany. In a substudy of 28 participants, total energy expenditure from doubly labeled water measurements was assessed. Results: Energy-adjusted, deattenuated correlation coefficients between the questionnaire and the recalls ranged from 0.54 for dietary fiber to 0.86 for alcohol. Cross-classification of quintiles of nutrient intakes from the questionnaire and recalls indicated severe misclassification to be

Rats of the Maudsley Reactive and Nonreactive strains were used in two light reinforcement experiments in a Skinner Box with two levers. Different response contingencies were compared in order to test the relative validity of the “stimulus change” and “preference” theories. The results did not support the preference theory, but are consistent with the stimulus change theory.

On M. Mercadier's Test of the Relative Validity of the Electrostatic and Electromagnetic Systems of Dimensions

A SERIES of papers, by M. Mercadier, on the dimensions of physical quantities, has recently been appearing in the Comptes Rendus. They are summarised and extended in the Journal de Physique (July, 1893, p. 289).

The self-report final-say decision measure of marital power has been declared invalid on the basis of low levels of interrelationships between this and other measures of marital power. However, there are alternative explanations for the poor performance of this measure to which little attention has been given previously: improper analytical procedures and computational errors. Data from 51 pairs of parents are used to show the results of miscalculations and inadequate procedures (similar to those encountered in previous marital power validity research) on the assessment of the relative validity of thefinal-say measure. In addition, these data are used to demonstrate that, even when analytical procedures are carefully selected, external criterion variables must be used if the meaning of interrelationships among measures is to be correctly interpreted.

OBJECTIVE:To develop and validate SF-12 osteoarthritis-specific health index (SF-12 OASHI). METHODS:Patient data on SF-12 and six osteoarthritis (OP) clinical variables (physician and patient global assessments, pain intensity, knee pain on weight bearing and motion, time to walk 50 feet) at baseline and week, 6, from two placebo-controlled clinical trials (n = 422), assessing efficacy of NSAIDs in OA patients were used. Using canonical correlation analysis, a SF-12 OASHI was developed in 75% of the sample (n = 317) by adding individual SF-12 item scores at baseline, each multiplied by their respective OA specific weights (canonical crossloadings on clinical variables). Validation (developmental sample) and cross-validation (25% holdout sample [n = 105], and another clinical trial sample [n = 170]) of the SF-12 OASHI were conducted by examining its correlation with clinical variables, and by computing the relative validity (RV) estimates of SF-12 OASHI as compared to physical (PCS12) and mental component summary scores (MCS12), using baseline and change scores at 6 weeks. Correlation between SF-12 component score and clinical variable was divided by correlation between OASHI and respective clinical variable to arrive at the RV. RESULTS: SF-12 OASHI demonstrated significant correlations with individual clinical variables ranging from −0.19 to −0.54 (p < 0.05). In general, SF-12 OASHI was more sensitive than the PCS12 and MCS12 scores as indicated by higher correlation coefficients with clinical variables, at baseline, in developmental and two cross-validation samples. At baseline, the RV coefficients for SF-12 OASHI ranged from 0.64 to 1.09 for PCS12 and 0.37 to 0.89 for MCS12. In general, SF-12 OASHI also showed more responsiveness to changes in clinical variables at 6 weeks as compared with PCS12 and MCS12 scores. CONCLUSION:The SF-12 OA-specific health index is a comprehensive and more sensitive measure of patient quality of life in OA as compared with PCS12 and MCS12.