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

Bujang Mohamad Adam,Omar Evi Diana,Foo Diana Hui Ping,Hon Yoon Khee 대한치과보존학회 2024 Restorative Dentistry & Endodontics Vol.49 No.1

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.

Academic Quality Management as a Means for Improving Institutional Productivity

Rahman, Bujang,Fanany, Rebecca 서울대학교 교육연구소 2013 아시아교육연구 Vol.14 No.1

A number of strategic factors, including facilities management, administrative management, leadership behavior, and participation of lecturers in scholarly activities, may contribute to institutional productivity. In the context of teacher training, productivity issues relate directly to the capabilities as well as number of graduates and their ability to integrate rapidly into the workforce. This study carried out at five teacher training institutions in the Indonesian province of Lampung makes use of path analysis to determine how selected strategic factors influence institutional productivity as measured by student outcomes. Its findings suggest that the interaction of the strategic factors of interest has the potential to increase satisfaction with management as a component of institutional productivity and might lead to policy developments that enhance student experience and outcomes.

Physicochemical sensitivities of tropical peat to electrokinetic environment

Afshin Asadi,Bujang B.K. Huat,Mohamed M. Hanafi,Thamer A. Mohamed,Nader Shariatmadari 한국지질과학협의회 2010 Geosciences Journal Vol.14 No.1

Tropical peat is unconsolidated superficial deposits with high non-crystalline colloid (humus) content, constituting the subsurface of wetland systems. Laboratory experiments were carried out on a very slightly decomposed fibric and a highly decomposed amorphous, undisturbed tropical peat soils, to determine the physicochemical effects on the peats due to electrokinetic (EK) treatment in terms of mechanisms and resulting effects in the presence of peat water. The different specimens were treated for 3, 6, 12, and 20-day periods. A constant electrical potential of 40 V was applied across the specimens. The untreated and treated specimens were tested for liquid limit (LL), undrained shear strength (Su), water content (WC), zeta potential (ζ), pH, and cation exchange capacity (CEC). The peat water flew from anode to cathode because of the negative charges on the humus. In the vicinity of the anode, the CEC and ζ of the specimens decreased, and the Su and LL of the specimens increased because of the acidic conditions, while alkaline conditions at the cathode had an opposite effect. The sensitivity of the amorphous peat to the EK environment was higher than the sensitivity of the fibric peat to the EK environment because of larger quantities of the colloids and quality of the charges. The acid/base distributions in EK soil processing influenced the soil surface charges, which were fully pH-dependent, resulting in the variations of the CEC and ζ. The ζ variations caused thinning and expanding of the diffuse double layer around the humus particles, and were linked to the flocculation and dispersion of the particles, and subsequently affected the LL and Su of the specimens. The study was found its significance in that it confirmed the relationship between the degree of peat decomposition and the peat sensitivity to the EK treatment.

Role of organic matter on electroosmotic properties and ionic modification of organic soils

Afshin Asadi,Bujang B. K. Huat,Mohamed M. Hanafi,Thamer A. Mohamed,Nader Shariatmadari 한국지질과학협의회 2009 Geosciences Journal Vol.13 No.2

Organic soils represent accumulations of disintegrated plant remains that have been preserved under condition of incomplete aeration and high water content. Using electrokinetic (EK) techniques to improve organic soils entails evaluating factors that define geoenvironmental behavior of organic soils. Electroosmotic properties were investigated to conceptualize EK phenomena. The results of the study showed that the zeta potential, specific surface area, water contents, and liquid limit (LL) increased as the organic content increased. The natural zeta potential of the organic soils varied from -11.2 to -20.8 mV according to the organic content, degree of humification, and soil pH. The negative charge in organic soils is highly pH dependent and surface charge is dropped to zero at pH 2.3 to 3.5. The greater degree of humification resulted in the higher zeta potential and lower pH at the iso-electric point. This paper also gives some insights on ionic modification, which is an innovative method that could be employed to change the water holding capacity of organic soils and its consistency. The Fe+3 ions had 20 to 30% pronounced effect on decreasing LL according to the organic content. Increasing the cation valence reduces the affinity of water to the organic soil surface and decreases LL as a major part of Atterberg’s consistency system. By the sound of peat and its environment, there is a great likelihood that EK techniques could be used to resolve peat’s difficulties from the geoenvironmental viewpoint. Organic soils represent accumulations of disintegrated plant remains that have been preserved under condition of incomplete aeration and high water content. Using electrokinetic (EK) techniques to improve organic soils entails evaluating factors that define geoenvironmental behavior of organic soils. Electroosmotic properties were investigated to conceptualize EK phenomena. The results of the study showed that the zeta potential, specific surface area, water contents, and liquid limit (LL) increased as the organic content increased. The natural zeta potential of the organic soils varied from -11.2 to -20.8 mV according to the organic content, degree of humification, and soil pH. The negative charge in organic soils is highly pH dependent and surface charge is dropped to zero at pH 2.3 to 3.5. The greater degree of humification resulted in the higher zeta potential and lower pH at the iso-electric point. This paper also gives some insights on ionic modification, which is an innovative method that could be employed to change the water holding capacity of organic soils and its consistency. The Fe+3 ions had 20 to 30% pronounced effect on decreasing LL according to the organic content. Increasing the cation valence reduces the affinity of water to the organic soil surface and decreases LL as a major part of Atterberg’s consistency system. By the sound of peat and its environment, there is a great likelihood that EK techniques could be used to resolve peat’s difficulties from the geoenvironmental viewpoint.

Cancers of the Young Population in Brunei Darussalam

Mohammad, Ibnu Ayyub,Bujang, Mas Rina Wati,Telisinghe, Pemasari Upali,Abdullah, Muhd Syafiq,Chong, Chee Fui,Chong, Vui Heng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Globally, the overall incidence of cancer is increasing as a result of ageing populations and changing lifestyles. Cancer is one of the leading causes of death, especially in the developed nations. Cancers affecting the young population are generally considered uncommon. This study assessed the demography and trends of cancers of the young in Brunei Darussalam, a small and developing Southeast Asia nation. Materials and Methods: All patients diagnosed with cancers between 2000 and 2012 were identified from the cancer registry maintained by the State Histopathology Laboratory. Cancers of the young was defined as any cancers diagnosed under the age of 40 years. Demographic data and the type of cancers were collected and analysed using SPSS Statistics 17.0. Results: Among the 6,460 patients diagnosed with cancer over the study period, 18.7% (n=1,205) were categorized as young with an overall decline in the proportion from 26.6% in 2000 to 18.8% in 2012 (p<0.001 for trend). Among all cancers of the young, the most common systems affected were gynecological (24.1%), hematological/lymphatic (15.8%), subcutaneous/dermatological/ musculoskeletal (10.5%), breast (10.5%) and gastrointestinal (9.9%). Overall, among the different systems, neurological (54.9%) had the highest proportion of cancers of the young followed by gynecological/reproductive (30.6%), hematological/lymphatic (39.9%), endocrine (38.7%), subcutaneous/dermatological/ musculoskeletal (22.3%) and the head and neck region (20.1%). There was a female predominance (66.9%) and the incidence was significantly higher among the Malays (20.1%) and expatriates (25.1%) groups compared to the Chinese (10.7%) and indigenous (16.8%) groups (p<0.001 for trend). Conclusions: Cancers of the young (<40 years) accounted for almost a fifth of all cancers in Brunei Darussalam with certain organ systems more strongly affected. There was a female preponderance in all racial groups. Over the years, there has been a decline in the overall proportion of cancers of the young. Selective screening programs should nevertheless be considered.

A Manifestation of Accounting Conservatism: A Case Study in Malaysia

ASON, Yvonne Joseph,BUJANG, Imbarine,JIDWIN, Agnes Paulus,SAID, Jamaliah Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.2

In the wake of several high-profile corporate accounting scandals, there has been evidence that companies are more eager to hire Chief Executive Officers (CEOs) with an accounting background. This signals that CEOs with an accounting background are recognized and trusted by the corporate world to boost the quality of financial reporting of a company. If it is so, in the context of combating the earnings management, hiring CEOs with an accounting background (being a conservative accounting practitioner), could become one of the effective internal corporate governance mechanisms (CGM) to bring down the earnings management activities. This study attempts to provide insight into the level of conservatism of the CEO with an accounting background. Following Basu (1997) and Khan and Watt (2009), the firm-year measure of conservatism (C_Score) was obtained, which later was associated with the accounting education of the CEO to determine their relationship. As expected, CEOs with accounting background exhibit a higher level of moral reasoning than their non - accounting educated counterparts. The finding of this study is useful to persuade the policymaker to consider lifting the trend of hiring a CEO with an accounting background as one of the best practices that the companies can work out to lessen earnings management activities.

WASTE STARCH FROM SAGO HAMPAS AS POTENTIAL GLUCOSE FEEDSTOCK FOR BIOETHANOL PRODUCTION

Abd?Aziz, S,Awg?Adeni, D. S.,Bujang, K.B,Hassan, M. A 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.10

Peat stabilization using cement, polypropylene and steel fibres

Kalantari, Behzad,Prasad, Arun,Huat, Bujang B.K. Techno-Press 2010 Geomechanics & engineering Vol.2 No.4

This article describes a laboratory research on stabilizing tropical peat using ordinary Portland cement (OPC) as a binding agent, and polypropylene and steel fibres as chemically inert additives. California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were carried out to evaluate the increase in the strength of the stabilized samples compacted at their optimum moisture contents and air cured for up to 90 days. The results show that the UCS values of stabilized peat samples increased by as high as 748.8% by using OPC (5%), polypropylene fibres (0.15%), and steel fibres (2%). The CBR values of the samples stabilized with OPC (5%), polypropylene fibres (0.15%), and steel fibres (4%) showed an increase of as high as 122.7%. The stabilized samples showed a shrinkage in volume upon air curing and this shrinkage was measured by an index called, volume shrinkage index (VSI). The highest VSI recorded was 36.19% for peat without any additives; and the minimum was 0% for the sample containing 30% OPC, 0.15% polypropylene fibres and 2% steel fibres. The technique of stabilizing peat with OPC, polypropylene and fibres, coupled with air curing, appears to be cost-effective compared with other frequently used techniques.