Conjoint analyses of the students' life satisfaction scale and the Piers-Harris self-concept scale

This study investigated the convergent and discriminant relationships between a children's life satisfaction measure, the Students' Life Satisfaction Scale (SLSS; Huebner, 1991a), and a widely used self-concept measure, the Piers-Harris Self-Concept Scale (Piers, 1984). Correlational and regression analyses demonstrated stronger relationships between the SLSS and the Piers-Harris Happiness and Satisfaction subscale compared to the other Piers-Harris subscales. The results of a conjoint principal components analysis also revealed predictable overlap between the SLSS and the Piers-Harris Happiness and Satisfaction subscale. Implications for future research are discussed.     

Analyzing and Selecting Instructional Strategies and Tactics

“Formulation of instructional strategy to match subject matter and learner requirements” is an integral part of most instructional design models (Andrews & Goodson, 1980, p.5). Yet the meaning and purpose of instructional strategies in these design models vary considerably. An instructional strategy in traditional design models usually refers to the selection of instructional delivery vehicles (e.g., lecture, demonstration, computer-assisted instruction) and support activities (e.g., practice exercises, tutoring) (cf. Tracey, Flynn, <& Legere, 1970). Contrast those conceptions with the many instructional strategies described in elaboration theory (Reigeluth & Stein, 1983), such as sub-sumptive sequencing, internally consistent orienting structures, synthesizers, summarizers, and cognitive strategy activators. What is obvious from these disparate conceptions is that instructional designers do not share a consistent definition of instructional strategies. Many of the activities that are referred to as instructional strategies are not in fact strategies, but rather are presentation vehicles. In this article, we first define instructional strategies and tactics in the context of an iterative design model. Instructional strategies are then distinguished from instructional tactics, which are the implementation of strategies. We then list the range of instructional strategies and tactics that implement them. Finally, we provide a decision tree for assisting designers to select appropriate instructional tactics.     

Interpreting the differences: A reply to Kaufman

Kaufman's critique of our article was based on a misunderstanding of our purpose and procedures. This reply clarifies those points and suggests further areas of concern regarding the McCarthy Screening Test.     

A case of vitamin B12 deficiency neurological syndrome in a young adult due to late-onset cobalamin C (CblC) deficiency: a diagnostic challenge

Vitamin B12 deficiency can present with neurologic and psychiatric symptoms without macrocytic anaemia. We describe a case of late-onset cobalamin C deficiency which typically presents with normal serum vitamin B12 concentrations, posing an additional diagnostic challenge. A 23-year-old woman with decreased muscle strength and hallucinations was diagnosed with ‘catatonic depression’ and admitted to a residential mental health facility. She was referred to our hospital for further investigation 3 months later. Heteroanamnesis revealed that the symptoms had been evolving progressively over several months. Magnetic resonance imaging (MRI) of the brain showed diffuse symmetrical white matter lesions in both hemispheres. Routine laboratory tests including vitamin B12 and folic acid were normal except for a slight normocytic, normochromic anaemia. Over the next 6 weeks her symptoms deteriorated, and she became unresponsive to stimuli. A new MRI scan showed progression of the white matter lesions. The neurologist requested plasma homocysteine (Hcys) which was more than 8 times the upper limit of normal. Further testing revealed increased methylmalonic acid and the patient was diagnosed with adult-onset cobalamin C deficiency. This case illustrates that Hcys and/or methylmalonic acid should be determined in patients presenting with neuropsychiatric symptoms suggestive of vitamin B12 deficiency with a normal serum vitamin B12 to rule out a late-onset cobalamin C deficiency.     

Intrachild variabilities: Will curtailment of testing harm minority children?

Compared intrachild variability of five-year-old children (49 black, 34 white) on the Primary Mental Abilities Test when subjects reached their fifth birthday after completing at least two years of preschool enrichment. Conclusions, although qualified on the basis of limited sample size, revealed wider intrachild variability with minority children. This suggests that abandonment of testing may increase instructional problems and possibly lower the quality of instruction provided minority and poor children.     

网球比赛分析的几个关键点

许多运动队将全程比赛分析作为教练员的指导工具,研究己方和对方运动员的类型、战术和技术特点.网球项目中,拥有个人分析师的运动员并不多见,大部分运动员和教练员使用分析设备和程序提供的客观、可靠的反馈信息,自己进行赛前及赛后分析.很多教练员采用其他教练员的有效训练模式,因为不是所有人都有时间去分析1000h的大满贯录像来找出战术差异,但可利用他人的分析结果.赛事录像记录的客观数据提供了充足的反馈信息,教练员可根据这些反馈信息调整技战术,进行针对性的训练.     

Coordination variability and skill development in expert triple jumpers

The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic and ground reaction force data were collected during the hop-step transition phase of the triple jump. Relative motion plots and a modified vector coding technique were used to quantify the coordination variability across the trials. The results were consistent with a U-shaped curve, representing coordination variability, as skill increases. The high coordination variability in less skilled athletes is present while the appropriate characteristics defining the movement coordination patterns are acquired. This coordination variability may not be beneficial to performance. As the refinement of these characteristics is achieved, coordination variability decreases, resulting in a more consistent or regulated performance. In the final stages of developing a skilled performance, a functional variability is accessed that brings flexibility to the system allowing it to cope with perturbations. This study highlights the need to address the learning effect when analysing coordination variability from a dynamical systems perspective.     

Repeated retention testing effects do not generalize to a contextual interference protocol

Three experiments examined repeated retention testing effects in a contextual interference (CI) protocol. Retention was assessed at 10 min and 24 hr following acquisition or at just 24-hr for the one-test conditions. Experiments 1 and 2 used speeded-response key-pressing tasks. Dependent measures were total time and errors. Experiment 3 used sequential-timing tasks. Dependent measures were absolute error and absolute constant error Results revealed CI effects in each experiment. Repeated retention testing effects were not found in Experiments 1 and 3. Experiment 2 revealed superior performance by the two-test condition compared to the one-test condition. This result was qualified by possible practice effects during the 10-min test. It was concluded that repeated retention testing does not present problems for most studies of CI.     

The influence of game location and outcome on behaviour and mood states among professional rugby league players

In this study, we examined the relationship between home and away matches on mood. In addition, the relationships between game location, game outcome, behavioural factors, and mood were investigated among 12 professional English rugby league players competing in the Super League. Participants completed daily diaries for 27 days. The diary consisted of six analogue scales measuring mood (relaxed-tense, energetic-weary, depressed-elated, tired-alert, anxious-calm, cheerful-miserable) as well as behavioural factors and self-rated performance. There were no significant differences in self-reported mood states leading up to home or away matches except for players feeling more tired when playing away. Significant relationships between mood and behaviours (e.g. sleep and eating) and subjective performance were observed. The outcome of the match was found to influence mood, with a defeat resulting in decreased mood. Our results show that game location did not influence mood and therefore does not provide an explanation for the home advantage.     

The role of upper torso and pelvis rotation in driving performance during the golf swing

While the role of the upper torso and pelvis in driving performance is anecdotally appreciated by golf instructors, their actual biomechanical role is unclear. The aims of this study were to describe upper torso and pelvis rotation and velocity during the golf swing and determine their role in ball velocity. One hundred recreational golfers underwent a biomechanical golf swing analysis using their own driver. Upper torso and pelvic rotation and velocity, and torso-pelvic separation and velocity, were measured for each swing. Ball velocity was assessed with a golf launch monitor. Group differences (groups based on ball velocity) and moderate relationships (r > or = 0.50; P < 0.001) were observed between an increase in ball velocity and the following variables: increased torso-pelvic separation at the top of the swing, maximum torso-pelvic separation, maximum upper torso rotation velocity, upper torso rotational velocity at lead arm parallel and last 40 ms before impact, maximum torso-pelvic separation velocity and torso-pelvic separation velocity at both lead arm parallel and at the last 40 ms before impact. Torso-pelvic separation contributes to greater upper torso rotation velocity and torso-pelvic separation velocity during the downswing, ultimately contributing to greater ball velocity. Golf instructors can consider increasing ball velocity by maximizing separation between the upper torso and pelvis at the top of and initiation of the downswing.