Recommended Sample Size Research Articles

Penalized Regression Methods With Modified Cross-Validation and Bootstrap Tuning Produce Better Prediction Models.

Risk prediction models fitted using maximum likelihood estimation (MLE) are often overfitted resulting in predictions that are too extreme and a calibration slope (CS) less than 1. Penalized methods, such as Ridge and Lasso, have been suggested as a solution to this problem as they tend to shrink regression coefficients toward zero, resulting in predictions closer to the average. The amount of shrinkage is regulated by a tuning parameter, commonly selected via cross-validation ("standard tuning"). Though penalized methods have been found to improve calibration on average, they often over-shrink and exhibit large variability in the selected and hence the CS. This is a problem, particularly for small sample sizes, but also when using sample sizes recommended to control overfitting. We consider whether these problems are partly due to selecting using cross-validation with "training" datasets of reduced size compared to the original development sample, resulting in an over-estimation of and, hence, excessive shrinkage. We propose a modified cross-validation tuning method ("modified tuning"), which estimates from a pseudo-development dataset obtained via bootstrapping from the original dataset, albeit of larger size, such that the resulting cross-validation training datasets are of the same size as the original dataset. Modified tuning can be easily implemented in standard software and is closely related to bootstrap selection of the tuning parameter ("bootstrap tuning"). We evaluated modified and bootstrap tuning for Ridge and Lasso in simulated and real data using recommended sample sizes, and sizes slightly lower and higher. They substantially improved the selection of , resulting in improved CS compared to the standard tuning method. They also improved predictions compared to MLE.

Predictors of parental acceptance to live attenuated influenza vaccine for children

ABSTRACT To determine the influencing factors of Chinese parents' intention and behavior for children to receive live attenuated influenza vaccine during the 2022–2023 influenza season. A theoretical model was developed and included seven constructs, and structural equation modeling was used to test 11 hypotheses. From October 2022 to December 2023, a survey was conducted across 38 medical institutions in four Chinese cities and their subordinate districts, counties, and rural areas. Parents who accompanied their children for vaccinations were selected through a randomization process based on their child’s medical card numbers. Measures were taken to minimize method bias, including a diverse geographical representation and random sampling. The survey resulted in the collection of 936 valid responses, exceeding the recommended sample size for structural equation model analysis and providing robust statistical inferences. During the study period, 936 respondents were included in the study. Perceived ease of use was verified to be a predictor of perceived usefulness and perceived value. Perceived usefulness was verified as a predictor of perceived value and behavioral intention. Knowledge was a significant antecedent of perceived value and risk perception of influenza disease. Risk perception of influenza disease was proved to be a significant predictor of perceived value and self-reported vaccination behavior. Perceived value significantly affected behavioral intention, and behavioral intention significantly affected self-reported vaccination behavior. Six demographic variables significantly moderate the theoretical models. The low vaccination coverage of live attenuated influenza vaccine (LAIV) among children in China suggests a need for a deeper understanding of the factors that influence vaccination rates. Particularly, effective strategies are necessary from policymakers and practitioners to elevate childhood LAIV coverage.

A new sample-size planning approach for person-specific VAR(1) studies: Predictive accuracy analysis.

Researchers increasingly study short-term dynamic processes that evolve within single individuals using N = 1 studies. The processes of interest are typically captured by fitting a VAR(1) model to the resulting data. A crucial question is how to perform sample-size planning and thus decide on the number of measurement occasions that are needed. The most popular approach is to perform a power analysis, which focuses on detecting the effects of interest. We argue that performing sample-size planning based on out-of-sample predictive accuracy yields additional important information regarding potential overfitting of the model. Predictive accuracy quantifies how well the estimated VAR(1) model will allow predicting unseen data from the same individual. We propose a new simulation-based sample-size planning method called predictive accuracy analysis (PAA), and an associated Shiny app. This approach makes use of a novel predictive accuracy metric that accounts for the multivariate nature of the prediction problem. We showcase how the values of the different VAR(1) model parameters impact power and predictive accuracy-based sample-size recommendations using simulated data sets and real data applications. The range of recommended sample sizes is smaller for predictive accuracy analysis than for power analysis.

Perceptions and Factors That Influence the Choice of Pathology as a Career Among Medical Students in Saudi Arabia.

Introduction Pathologists play a pivotal role in diagnosing diseases and improving patient care. Nonetheless, research indicates that a mere fraction of medical school graduates opt for a career in pathology, ranging from 1% to 3%. Diverse factors influence students' perceptions of pathology, encompassing lifestyle, patient interaction, and income. Aim The aim of this study was to assess the perceptions and factors that influence students' selection of pathology as a career in Saudi Arabia. Methodology A cross-sectional, self-administered electronic questionnaire was distributed among students from various regions of Saudi Arabia. The questionnaire encompassed both quantitative and qualitative data. To ensure statistical rigor, a confidence level of 95%, response distribution of 10%, and margin of error of 5% were applied. Accordingly, the recommended sample size of 150 participants was determined. Data analysis was performed using IBM SPSS Statistics for Windows, Version 24.0 (IBM Corp.,Armonk, NY), with the chi-square test applied at a significance level ofP < 0.05. Results Among the 664 participating students, 130 (19.6%) indicated an interest in pathology, of whom only 19 (2.9%) regarded it as their primary choice. No statistically significant difference was found between the male and female students or between the students in foundational and clinical years. Conclusions The female students generally held a more favorable perception of pathology, acknowledging its clinical significance and role in diagnosis, prognosis, and patient management. The absence of nocturnal calls emerged as the most encouraging factor, while limited patient interaction emerged as the primary deterrent in choosing pathology.

Spatial ecotoxicology: what we know about the relationship between avian movements and contaminant levels

Birds are widely used as indicators of environmental contamination because they integrate signals across space and time. However, this advantage also means that locating the source of pollution can be challenging, especially for species that migrate large distances. Historically, the assignment of contaminant burden to particular life stages or locations has been made by sampling tissues with varying time signals and associating those signals with locations assigned from band recoveries or stable isotope analyses. Unfortunately, these assignments are geographically coarse. More recently, tracking devices have been increasingly used to determine more precisely where and when contamination is likely to occur. Here, we review current knowledge on using tracking devices to examine the relationship between avian movements and contaminant loads. We found 42 published articles with samples collected from 1986 to 2021 that used tracking devices to examine the relationship between avian movement and contaminant loads, where studies were primarily concentrated in the northern hemisphere, notably in the North Atlantic. Tracking methodology varied widely across studies to date, but the use of radiotransmitters and satellite tags generally decreased as newer technologies, such as global positioning systems and geolocation sensors, were developed. Blood and feathers were the most commonly used tissues to assess contaminant concentrations, but sample sizes were often low (&lt;40, the recommended sample size for some tracking or contaminant studies), and one-quarter of studies did not statistically test the relationship between tracking data and contaminant concentrations. Moving forward, studies should (1) consider statistical power; (2) consider tissue turnover rates, contaminant turnover rates, and tracking device resolution; (3) examine tissues that inform different time scales; 4) explore the impacts of contaminants on behaviour and movement; and 5) increase collaboration, standardization, and information sharing across existing tracking or contaminant monitoring programs. Focusing on these aspects will enhance our ability to identify the source, transport, and fate of contaminants in avian species across the globe.

Harmonizing Aesthetics and Psychological Well-being: An Indepth Exploration of the Integrative Impact of Dysport in Cosmetic Procedures

This research delves into the intricate interplay between aesthetic intelligence, aesthetic sensitivity, and psychological well-being within the framework of positive psychology, with a particular emphasis on the integrative impact of Dysport in cosmetic procedures. By recognizing the significant influence of environmental aesthetics on individual health and well-being, this study seeks to illuminate the relationship between aesthetic intelligence and psychological well-being while considering the role of Dysport in cosmetic procedures. Employing a correlational research design, structural equation modeling was utilized as the methodological approach. The research cohort comprised all students enrolled at Bu-Ali Sina University during the academic year 2018-2019. Employing cluster sampling, 384 students were selected based on the recommended sample size for structural equation modeling. The instruments included the Ryff Well-being Scale, the Aesthetic Intelligence Scale developed by Rashid et al., and Abdulsalami's Aesthetic Sensitivity Scale. Findings revealed significant direct impacts of both aesthetic intelligence and aesthetic sensitivity on psychological well-being. Moreover, aesthetic intelligence demonstrated a direct and significant effect on aesthetic sensitivity. Exploration of indirect relationships indicated that aesthetic intelligence, mediated by aesthetic sensitivity, significantly influenced psychological well-being. These findings underscore the importance of individuals' awareness and appreciation of environmental beauty, including the role of Dysport in cosmetic procedures, in positively contributing to psychological well-being.

Harmonizing Aesthetics and Psychological Well-being: An Indepth Exploration of the Integrative Impact of Dysport in Cosmetic Procedures

This research endeavors to delve into the intricate interplay between aesthetic intelligence, aesthetic sensitivity, and psychological well-being within the framework of positive psychology. Recognizing the profound influence of environmental aesthetics on individuals' health and well-being, this study aims to illuminate the relationship between aesthetic intelligence and psychological well-being, with aesthetic sensitivity acting as a mediating factor. Employing a correlational research design, structural equation modeling was applied as the methodological approach. The research cohort comprised all students enrolled at Bu-Ali Sina University during the academic year 2018-2019. Employing cluster sampling, 384 students were selected based on the recommended sample size for structural equation modeling. The instruments employed in this study included the Ryff Wellbeing Scale (2), the Aesthetic Intelligence Scale developed by Rashid et al. (2017), and Abdulsalami's (2013) Aesthetic Sensitivity Scale. The findings derived from structural equations analysis revealed that both aesthetic intelligence and aesthetic sensitivity exerted a significant direct impact on psychological well-being. Furthermore, aesthetic intelligence demonstrated a direct and significant effect on aesthetic sensitivity. The exploration of indirect relationships indicated that aesthetic intelligence, acting through the mediation of aesthetic sensitivity, significantly influenced psychological well-being. Considering these outcomes, it can be inferred that individuals' awareness and appreciation of environmental beauty positively contribute to their psychological well-being. Consequently, the development of educational programs aimed at enhancing aesthetic capabilities in individuals holds the potential to elevate overall well-being.

Sample size determination for conducting a pilot study to assess reliability of a questionnaire.

This article is a narrative review that discusses the recommended sample size requirements to design a pilot study to assess the reliability of a questionnaire. A list of various sample size tables that are based on the kappa agreement test, intra-class correlation test and Cronbach's alpha test has been compiled together. For all calculations, type I error (alpha) was set at a maximum value of 0.05, and power was set at a minimum value of 80.0%. For the kappa agreement test, intra-class correlation test, and Cronbach's alpha test, the recommended minimum sample size requirement based on the ideal effect sizes shall be at least 15, 22, and 24 subjects respectively. By making allowances for a non-response rate of 20.0%, a minimum sample size of 30 respondents will be sufficient to assess the reliability of the questionnaire. The clear guideline of minimum sample size requirement for the pilot study to assess the reliability of a questionnaire is discussed and this will ease researchers in preparation for the pilot study. This study provides justification for a minimum requirement of a sample size of 30 respondents specifically to test the reliability of a questionnaire.

Modified inverse propensity weighting method to alleviate estimation errors in the model with multiple endogenous variables

Multiple mental health disorders affect on decisions of people. The disorders are also outcomes of other factors. Health studies commonly follow an inverse propensity weight (IPW) method to address estimation errors associated with the presence of one confounder or covariate number exceeding the recommended sample size. However, approaches of IPW appropriate to alleviate the estimation error associated with multiple confounders distributed unequally in the study samples were not explained in our search literature. This study used longitudinal cohort data from Christchurch Health and Development Study and demonstrated IPW approach to address two confounders with similar natures in terms of etiological process. In our sample, some individuals had no mental health disorder at all, while others had either one of depression or anxiety or both. The methodological step to evaluate a new IPW approach include* Estimated IPWs from all possible combinations of the major depression and anxiety disorder: (a) IPW based on anxiety factor only assuming both mental health problems resulted from the same etiological processes; (b) IPW based on major depression factor only assuming both mental health problems resulted from the same etiological processes; (c) IPW assuming three (independent) categories of etiological processes: neither; either; both of major depression or anxiety disorder, (d) IPW assuming four (independent) categories of etiological processes: neither; major depression only; any anxiety disorder only; both. (e) No IPW or control model (no confounding problem.•Estimated outcome model with one each IPW at a time and one without IPw (control model).•Compared fit statistics of all estimated models.•The IPW derived assuming four categories of etiological processes produced the robust based fit statistics criteria. The study showed significant effects of both mental health problems on investment but the anxiety revealed a stronger effect than that of major depression.

Community pharmacists' perceptions of the POM to P reclassification of medicines for sexual and reproductive health – A survey study

Abstract Introduction In the UK, medicines reclassification is the process of changing the legal classification of a medication, such as from a prescription-only medicine (POM) to a pharmacy (P) or general sales list (GSL) medicine.1 It is overseen by the Medicines and Healthcare products Regulatory Agency (MHRA). and improves patient access to certain medications while ensuring safeguards are in place for their safe and responsible use.2 A number of the most recent POM to P reclassifications have been for medications used in sexual and reproductive healthcare. Aim To investigate community pharmacists' (CPs’) perceptions of POM to P medicine reclassifications for sexual and reproductive health: sildenafil citrate (Viagra Connect, for erectile dysfunction), desogestrel (Hana/Lovima, for contraception), and estradiol hemihydrate (Gina, for vaginal atrophy). Methods The study population was all CPs in Greater London. The survey consisted of 59-questions in five sections. The first section was for general perceptions about the reclassification of medicines, while the other sections were specific to the medicines studied. The final section was demographics. Question types included multiple-choice, 5-point Likert scale, and free text. The recommended sample size was 340 (95% CI), therefore, 398 CPs, in 210 pharmacies, were approached. Ethical approval was obtained from the university ethics committee. Participants were posted a participant information sheet (PIS) one week before distribution of the survey as a hard copy. The survey was also available on Microsoft Forms. Data were analysed in Microsoft Excel and Statistical Package for Social Sciences (SPSS). Descriptive statistics were given in numbers and percentages. Results The response rate was 37.7% (N=150/398). Most CPs (88%) perceived that medication reclassification increased their role and provided greater access to medicines for the public. However, less than half (44%) had a good understanding of the reclassification process. Sildenafil was available to purchase in all of the visited pharmacies, however, desogestrel was only sold in 50% of them, and estradiol was sold in only 28%. Reasons cited for not selling desogestrel and/or estradiol included lack of public awareness about the availability of these products, and a lack of public interest in purchasing them. While the availability of sildenafil as a P medicine was seen as a positive for improving safe access, many CPs (86%) expressed concerns about the high risk of its misuse. In terms of training, the available training for sildenafil received higher ratings compared to that for desogestrel or estradiol. Most CPs (67%) indicated that having case studies incorporated into the training for POM to P switches helped them understand which patients could safely purchase these medications. Discussion/Conclusion CPs are positive about the availability of sexual and reproductive health medications over the counter. They do have concerns, however, about the potential of some of these medications to be misused, and also feel that more awareness of the availability of these products needs to be raised. Those producing training materials for reclassified medications should incorporate case studies as these support CP decision making. A limitation of this study was that the recommended sample size was not achieved.

Accurate Determination of Trace Water in Organic Solution by Quantitative Nuclear Magnetic Resonance.

A new method accompanied by a derived equation for accurate determination of trace water was developed by using quantitative 1H nuclear magnetic resonance (qNMR) spectroscopy. Given that the response for each chemically distinct moiety is uniformly proportional to the number of the corresponding resonant nuclei within the analyte, it is practicable to directly quantify the water content via its proton number using qNMR. In this study, three water standards with known water contents (e.g., 10.02, 1.006, and 0.103 mg/g), which were accurately determined by a well-established Coulometric Karl Fischer (CKF) titration method, were measured by using the developed qNMR method. An excellent agreement between the results from these two methods was obtained. Then, the water content of Sudan I was determined by high-field NMR (HF-NMR) spectroscopy, and the water contents of acetone and bioethanol were measured by low-field NMR (LF-NMR) spectroscopy. These results were compared with the water content measured by the CKF method to confirm the applicability of the established qNMR method. The developed method can eliminate the influences of environmental humidity and background water in the solvent; subsequently, the results calculated by the derived equation were comparable to the nominal values. Under the optimal conditions, the limit of quantitation of this method was as low as 6.7 μg. The recommended sample sizes for practical samples with various water contents (e.g., 10.02, 1.006, and 0.103 mg/g) were determined to be 5, 50, and 60 mg, respectively, which are much smaller than those required for the CKF method. The new method has a static and stable process without any side reactions, and the traceability to the SI unit can be directly achieved through the NMR internal standard. This method overcomes the limitations of the CKF method, especially for measuring methanol-insoluble substances.

The Impact of Social-media Celebrity on Buying Behavior of Retailer Customers in Riyadh, KSA

This study aimed to measure the impact of celebrity endorsement on the buying behavior of retailer customers in Riyadh. The study population consists of all buyers of hyper-stores in Riyadh. The unit of analysis was the Saudis and non-Saudis who are employed in the government and private sectors in Riyadh. The estimates showed that the size of the population reached 3.87 million people in 2019. The stratified-sample technique was used and the recommended sample size reached 387 buyers. The results of structural equation modeling (SEM) showed a statistically significant impact of celebrity on the purchasing behavior of retailer customers in Riyadh. Finally, the study presented several recommendations and marketing implications to enhance the role of celebrity in purchasing decisions.

The Effects of Sports Sponsorship on Buying Response for Jordanian Fans

This study aims to investigate the effect of sports sponsorship activities on the buying behavior of sports audiences, in addition to determining the statistical differences in the level of sports sponsorship activities and the buying response according to some organizational and demographics. The research population consists of Jordanian sports audiences who live in Amman city. The Convenience sampling technique is used. The researcher selects the respondents from coffee shops, cafes, famous malls in Amman, and social media users. The recommended sample size is 385. The unit of analysis is the Jordanian who attended and watched the sports activities for up to 19 years living in Amman. The study concludes that sports sponsorship activities strongly positively affected the buying response “ATR” of the sports audience. It is found statistically significant differences in the awareness tend to males and B. A degree holder. It is also found that the age between 42 - 46 is the most experienced, but it is found that there are no differences between the sports audience segments in the repeated purchase stage. Finally, it is a statistically significant difference in sponsorship activities and tends to the telecom companies in Jordan. The study presents a set of recommendations that enhance using the sponsorship in the local sports market.

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Purpose: The objective of this research is to investigate how omnichannel experience impacts trust, how trust influences repurchase intention, how omnichannel experience affects repurchase intention, and how omnichannel experience affects repurchase intention when trust is considered as a mediating factor.&#x0D; &#x0D; Theoretical framework: Omnichannel experience is defined as a sales system that offers customers freedom and independence to experience and obtain information through various channels. The five dimensions of omnichannel experience are connectivity, integration, consistency, flexibility, and personalization. Trust is a set of beliefs related to the integrity, benevolence, and ability of the other party, while repurchase intention is the customer's desire to repurchase a product or reuse the services provided by the company. The four dimensions of consumer trust are benevolence, ability, integrity, and willingness to depend. The research aims to determine the effect of omnichannel experience on trust and how it affects repurchase intention.&#x0D; &#x0D; Design/methodology/approach: 10 retail companies with the highest consumer value in 2021 based on YouGov. Data will be collected through questionnaires distributed to customers who have shopped at the object of research retail stores online and offline. The study will use a quantitative approach with descriptive and inferential analyses, and the data will be analyzed using Structural Equation Modeling (SEM) analysis. The minimum recommended sample size is 330 samples&#x0D; &#x0D; Findings: The study found that the omnichannel experience has a positive effect on trust, and trust has a positive effect on repurchase intention. Furthermore, the study revealed that trust plays a mediating role between omnichannel experience and repurchase intention. These findings suggest that creating an omnichannel experience that enhances trust may lead to increased repurchase intention among retail consumers.&#x0D; &#x0D; Research, Practical &amp; Social implications: By understanding the positive impact of omnichannel experience on trust and repurchase intention, retailers can provide seamless, integrated shopping experiences across multiple channels. This can include offering online shopping with in-store pickup options, providing personalized recommendations based on customer preferences, and implementing transparent and reliable return policies to build trust. By enhancing omnichannel experiences and building trust, retailers can create a more positive shopping experience for customers, leading to higher satisfaction levels and increased loyalty&#x0D; &#x0D; Originality/value: This study provides a comprehensive theoretical framework to explain the relationship between omnichannel experience, trust, and repurchase intention, which is a relatively unexplored area in the retail industry. The study's findings reveal that trust plays a mediating role between omnichannel experience and repurchase intention, suggesting that building trust through an omnichannel experience may lead to increased repurchase intention among retail consumers.

Exploring the Influence of Omnichannel Experience on Trust and Repurchase Intention in Retail Companies: Evidence from Indonesia

Purpose: The objective of this research is to investigate how omnichannel experience impacts trust, how trust influences repurchase intention, how omnichannel experience affects repurchase intention, and how omnichannel experience affects repurchase intention when trust is considered as a mediating factor.&#x0D; &#x0D; Theoretical framework: Omnichannel experience is defined as a sales system that offers customers freedom and independence to experience and obtain information through various channels. The five dimensions of omnichannel experience are connectivity, integration, consistency, flexibility, and personalization. Trust is a set of beliefs related to the integrity, benevolence, and ability of the other party, while repurchase intention is the customer's desire to repurchase a product or reuse the services provided by the company. The four dimensions of consumer trust are benevolence, ability, integrity, and willingness to depend. The research aims to determine the effect of omnichannel experience on trust and how it affects repurchase intention.&#x0D; &#x0D; Design/methodology/approach: 10 retail companies with the highest consumer value in 2021 based on YouGov. Data will be collected through questionnaires distributed to customers who have shopped at the object of research retail stores online and offline. The study will use a quantitative approach with descriptive and inferential analyses, and the data will be analyzed using Structural Equation Modeling (SEM) analysis. The minimum recommended sample size is 330 samples&#x0D; &#x0D; Findings: The study found that the omnichannel experience has a positive effect on trust, and trust has a positive effect on repurchase intention. Furthermore, the study revealed that trust plays a mediating role between omnichannel experience and repurchase intention. These findings suggest that creating an omnichannel experience that enhances trust may lead to increased repurchase intention among retail consumers.&#x0D; &#x0D; Research, Practical &amp; Social implications: By understanding the positive impact of omnichannel experience on trust and repurchase intention, retailers can provide seamless, integrated shopping experiences across multiple channels. This can include offering online shopping with in-store pickup options, providing personalized recommendations based on customer preferences, and implementing transparent and reliable return policies to build trust. By enhancing omnichannel experiences and building trust, retailers can create a more positive shopping experience for customers, leading to higher satisfaction levels and increased loyalty&#x0D; &#x0D; Originality/value: This study provides a comprehensive theoretical framework to explain the relationship between omnichannel experience, trust, and repurchase intention, which is a relatively unexplored area in the retail industry. The study's findings reveal that trust plays a mediating role between omnichannel experience and repurchase intention, suggesting that building trust through an omnichannel experience may lead to increased repurchase intention among retail consumers.

The association of chest compressor&amp;apos;s physical activity level with the quality of continuous chest compressions during a stimulated cardiac arrest in an education center

Background: Cardiopulmonary resuscitation (CPR) is a lifesaving procedure performed by qualified rescuers. The quality of CPR depends on effective chest compression (CC) characteristics: rate, depth, hand position, and chest recoil. Besides CC, previous research has proven that physical activity level (PAL) varies among rescuers and affects CPR quality. This study aims to assess the association between PAL and the quality of continuous chest compressions-cardiopulmonary resuscitation (CCC-CPR) for 5 minutes by qualified rescuers at the National Guard Hospital in Jeddah (NGHA-J). Methods: This is a cross-sectional study. The global physical activity questionnaire was used to measure the participants&amp;apos; PALs, and the SimMan 3G mannequin was used to measure the four CC characteristics. The recommended sample size is 45 of the rescuers at NGHA-J. Results: A total of 45 members were involved in the study, and most participants were 27 (60%) males. Most participants are classified as having high PAL 21(46.67%). The study indicates that there is no significant effect among the PALs and the CCC-CPR effectiveness according to (p 0.65) which is determined by the non-parametric Kruskal Wallis test. The optimal effective CCs between the three groups of PALs were achieved by the moderate PAL participants with a median of 47.5 (IQR 35). Conclusion: The study findings deny any relationship between the quality of the CCC-CPR and the PAL of the rescuers.

Effects of Perceptions of The Immediate Surroundings on Obesity and Physical Activity Levels in University Students

The aim of this study was to examine the effects of perception of the close environment on obesity and physical activity levels in university students. Included in this study were 113 students between 18–25 years of age, taking into account that there may be erroneous and missing data according to the 95% confidence level in the pre-sample size calculation table according to the confidence level and acceptable error for the research, 10% more than the recommended sample size was calculated and 113 students participated. Up to 20% of the participants were fitted with a pedometer and heart rate monitor for 1 day to determine their objective physical activity levels. Height measurement, body weight measurement, bioimpedance analysis, International Physical Activity Questionnaire-Short Form (IPAQ-SF), pedometer, heart rate, and Immediate Walkability Perception Questionnaire (IWPQ) were applied to the participants. As a result, a significant relationship was found between the number of steps and the shops, facilities, and other nearby places in the vicinity (P < 0.05; r = –0.353). At the same time, a significant relationship was observed between the stores, facilities, and other nearby places in the vicinity and the level of physical activity (P < 0.13; r = –234). Relationships were found between the body mass index (BMI), Body fat percentage, and abdominal circumference data, which are considered as obesity indicators, and the sub-dimensions of the perception of walkability in the immediate environment, but none of these were statistically significant.

The Impact of Immediate Sales Promotion Techniques on Brand Recall: Study on Middle Income Group Residents in Riyadh

The study aimed to resolve the impact of immediate sales promotion techniques on brand recall. The independent variable is divided into three sub-variables: price reductions, free samples, and purchasing vouchers. The research population is all foreign workers in the private sector in Riyadh. The figures show that the population size reached 3.4 million in 2021. A proportional stratification method was used, and the recommended sample size was 387 customers. The study concludes that a statistical impact of free samples on brand recall and there was no impact of immediate techniques on brand recall. Finally, the study presented and recommended a set of marketing implications to develop the uses of sales promotion techniques in retail stores.

Power Analysis for the Random Intercept Cross-Lagged Panel Model Using the powRICLPM R-Package

The random intercept cross-lagged panel model (RI-CLPM) is a popular model among psychologists for studying reciprocal effects in longitudinal panel data. Although various texts and software packages have been published concerning power analyses for structural equation models (SEM) generally, none have proposed a power analysis strategy that is tailored to the particularities of the RI-CLPM. This can be problematic because mismatches between the power analysis design, the model, and reality, can negatively impact the validity of the recommended sample size and number of repeated measures. As power analyses play an increasingly important role in the preparation phase of research projects, an RI-CLPM-specific strategy for the design of a power analysis is detailed, and implemented in the R-package powRICLPM. This paper focuses on the (basic) bivariate RI-CLPM, and extensions to include constraints over time, measurement error (leading to the stable trait autoregressive trait state model), non-normal data, and bounded estimation.

Morpho-Agronomic Characterization, Sample Size, and Plot Size for the Evaluation of Capsicum chinense Genotypes

The Amazon is a center of diversity for Capsicum chinense Jacq., with wide genetic and morphological variability, but little exploration has been performed there to facilitate their improvement. This study aimed to characterize and evaluate C. chinense genotypes for the development of cultivars by determining the optimal size of the experimental plot and the minimum sample size to ensure a precise estimation of yield. A total of 23 genotypes were evaluated, and in multivariate analyses, the plants were characterized by 21 morphological descriptors and eight quantitative traits related to biometry and yield. The recommended sample size for fruit evaluation was defined based on simulations with subsample resampling and evaluation of the semi-amplitudes of the confidence interval of the mean estimate. The optimal plot size was estimated by the modified maximum curvature method. The similarity coefficients among the genotypes ranged from 0.54 to 0.93, indicating that the established clusters contained important information for future crosses. According to the sample size methodologies, 25 to 40 fruits should be sampled for valid evaluations of biometric traits. Experiments with five to eight plants per plot are recommended to test progenies of the species, ensuring good experimental precision combined with high selection accuracy for yield traits.