Abstract critiques External, construct, internal…

Abstract I The purpose of this study was to describe the change in physical fitness of middle- aged adults with an intellectual disability over a period of 13 years. Participants were 32 adults who worked in a supported work environment in Montreal and had been participants in a physical fitness study in Using the Canadian Standardized Test of Fitness, the participants were evaluated for cardiovascular endurance, muscular strength, muscular endurance, flexibility, and body composition. A home visit prior to the testing session refamiliarized the participants with the test procedures. Two forms of analysis were used to describe the change in fitness over 13 years. First, a 2 x 2 (Group x Time) analysis of variance for each dependent variable assessed change over time. Second, effect sizes were calculated to measure the magnitude of change in fitness over the 13- year period in comparison to those without an intellectual disability. As expected, the physical fitness levels of the participants were low when compared to those without a disability and declined over the 13 years. In addition, the magnitude of change over the 13 years, as compared to those without a disability, was greater for male and female participants for body mass index and percentage of body fat and for female participants for cardiovascular endurance and sit-ups. It appears that adults with an intellectual disability may be particularly at risk for declining health associated with aging and low physical fitness. Internal validityExternal validity Construct validity

Abstract – I. External val. Population –middle-aged adults with an intellectual disability Sample –middle-aged adults with an intellectual disability –who worked in a supported work environment in Montreal and had been participants in a physical fitness study in 1983 –in comparison to those without an intellectual disability. Setting –A home visit prior to the testing session refamiliarized the participants with the test procedures Internal validityExternal validity Construct validity

Abstract – I. Construct validity Dependent variables –physical fitness cardiovascular endurance, muscular strength, muscular endurance, flexibility, and body composition Canadian Standardized Test of Fitness Independent variables –time, gender, intellectual disability Relationship –Change in physical fitness over time Questions: –How well is each construct operationalized? Might any weakness in the operationalizations alter the relationship of interest? Internal validityExternal validity Construct validity

Abstract – I. Internal validity Design: –NEGD –Pre-test – Post-test Non-equivalent groups design, with sub groups for gender Control over causality: –Temporal precedence, covariance are ok. The problems stem from lack of control over alternative explanations –No random assignment, and not clear where other non-disabled participants are drawn from (social threats?) Internal validityExternal validity Construct validity

Abstract II It has been shown in classical strength training studies using high loads that improvements in rate of force development are mainly due to adaptations in the intramuscular coordination. Adaptations following sensorimotor training were also characterized by improvements in the rate of force development during maximum voluntary isometric contraction. The purpose of the present study was to investigate neuromuscular adaptations of combined sensorimotor and classical strength training. Eighteen subjects were randomly assigned to two groups. Group 1 (SMT-HST) had to perform a period of sensorimotor training at first and a high- intensity strength training afterwards. Group 2 (HST-SMT) performed the high intensity strength training at first and the sensorimotor training after. Maximum voluntary isometric contraction and neuromuscular activation were measured at three occasions: Before training, after the first, and after the second period. The results after the first period confirmed the positive effects of both training regimen on rate of force development (13 % [SMT-HST] and 27 % [HST-SMT], p < 0.05) and on maximum strength (9 % [HST-SMT] and 12 % [SMT-HST], p < 0.05) during maximum voluntary contraction. Improvements caused by sensorimotor training could only be achieved, when it was performed at first. It is supposed that classical strength training with high loads basically improves the mechanical efficiency of the effectors, whereas sensorimotor training alters the afferent input on the central nervous system. In combination, the sensorimotor training can have preconditioning effects on the strength training. A combination of both training methods can thus be recommended, if the sensorimotor training is performed at first. Internal validityExternal validity Construct validity

Abstract – II. External val. Population –? Sample –? 18 participants…no more known Setting –? Internal validityExternal validity Construct validity

Abstract – II. Construct validity Dependent variables –Rate of force development –Maximum strength Independent variables –Time, treatments Relationship –Change in measures of strength as a result of the 2 treatments Questions: –How well is each construct operationalized? Might any weakness in the operationalizations alter the relationship of interest? Internal validityExternal validity Construct validity

Abstract – II. Internal validity Design: –Pretest-post-test, switched replication, randomized design –Pre-test – Post-test Non-equivalent groups design, with sub groups for gender Control over causality: –Temporal precedence, covariance ok. –Random assignment used, so multiple group threats ok –Switched replications provide some protection against group threats (no compensatory rivalry) Internal validityExternal validity Construct validity