Manipulating the alpha level cannot cure significance testing

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple independent studies. When evaluating the strength of the evidence, we should consider, for example, auxiliary assumptions, the strength of the experimental design, and implications for applications. To boil all this down to a binary decision based on a p-value threshold of 0.05, 0.01, 0.005, or anything else, is not acceptable

Association of Type 1 Diabetes vs Type 2 Diabetes Diagnosed During Childhood and Adolescence With Complications During Teenage Years and Young Adulthood

The burden and determinants of complications and comorbidities in contemporary youth-onset diabetes are unknown

Location, technical change and labor migration in a heterogeneous industry

Individual firms in an industry may exhibit differences in technical capabilities, economies of scale and size. These characteristics affect the firms\u27 decisions regarding factor use and production location. This paper explores the relations among these decisions in a setting of a single interregional output market and segmented interregional labour markets. Firms are seen to react to changing labour- and output-market characteristics, changes that reflect earlier actions by other producers. Reactions are constrained by the technical capabilities and capital assets of individual firms, and by locational inertia based on the longevity of fixed capital stock. The overall system evolves as a result of factor-market response and the convergence of firm charactereristics on a limited number of viable types. These interactions are simulated, and the results are discussed in the light of studies of industrial organization and regional industrial change in the US

Factors Influencing Wagers in Simulated Blackjack

To understand some of the deviations from recommended optimal play in Blackjack, gamblers were considered to be decision makers who used decision rules to predict outcomes. The size of their wagers were used as an index of the confidence of these predictions. If this were the case, players\u27 decisions would be affected by time pressure, short-term probability of winning, and their perceived control of outcomes. Players\u27 wagering on a simulated game of Blackjack was examined to assess the feasibility of this approach. The computer simulation of Blackjack used simplified rules (no splitting, doubling down, insurance, etc.), and the probability of winning was controlled by the computer. Subjects could either choose whether they were dealt extra cards, or could bet upon another player. The other player was a computer algorithm that sat upon a total of fifteen. To examine effects of time pressure upon confidence of judgments, the time allowed to place a bet, and to choose extra cards, was manipulated. Twelve subjects played 20 hands under each of the experimental conditions. The mean amounts wagered, and players\u27 choice of cards were both examined. The results suggested that deviations from optimal play can in part be understood in terms of players\u27 decision processes, that are influenced by the time available to make a decision, the short-term probability of winning, and perceived control of outcomes; each factor may potentiate the effects of the others

Commitment Strength, Alcohol Dependence and Healthcall Participation: Effects On Drinking Reduction in HIV Patients

Background: The role of three factors in drinking outcome after brief intervention among heavily drinking HIV patients were investigated: strength of commitment to change drinking, alcohol dependence, and treatment type: brief Motivational Interview (MI) only, or MI plus HealthCall, a technological extension of brief intervention. Methods: HIV primary care patients (N= 139) who drank ≥4 drinks at least once in the 30 days before study entry participated in MI-only or MI. +. HealthCall in a randomized trial to reduce drinking. Patients were 95.0% minority; 23.0% female; 46.8% alcohol dependent; mean age 46.3. Outcome at end of treatment (60 days) was drinks per drinking day (Timeline Follow-Back). Commitment strength (CS) was rated from MI session recordings. Results: Overall, stronger CS predicted end-of-treatment drinking (p\u3c. .001). After finding an interaction of treatment, CS and alcohol dependence (p= .01), we examined treatment. ×. CS interactions in alcohol dependent and non-dependent patients. In alcohol dependent patients, the treatment. ×. commitment strength interaction was significant (p= .006); patients with low commitment strength had better outcomes in MI. +. HealthCall than in MI-only (lower mean drinks per drinking day; 3.5 and 4.6 drinks, respectively). In non-dependent patients, neither treatment nor CS predicted outcome. Conclusions: Among alcohol dependent HIV patients, HealthCall was most beneficial in drinking reduction when MI ended with low commitment strength. HealthCall may not merely extend MI effects, but add effects of its own that compensate for low commitment strength. Thus, HealthCall may also be effective when paired with briefer interventions requiring less skill, training and supervision than MI. Replication is warranted

Motivational Interviewing: A Pilot Test of Active Ingredients and Mechanisms of Change

Motivational interviewing (MI) is an effective treatment for substance use disorders (SUDs) that focuses on resolving ambivalence and increasing commitment to positive behavior change. Although MI has a well-developed clinical theory, research findings have been mixed in supporting its view of how change occurs. The primary aim of this pilot study was to test hypothesized MI active ingredients and mechanisms of change in reducing drinking during the initiation of a behavior change episode. Problem drinkers (N = 89) seeking treatment were randomly assigned to MI, relational MI without directive elements (spirit-only MI [SOMI]), or a self-change (SC) control condition. Participants were followed during an 8-week treatment period. The first 2 of 4 treatment sessions were videotaped and coded for fidelity, discriminability, and change talk. Overall, conditions demonstrated high fidelity. As predicted, change talk significantly increased in MI relative to the SOMI condition. Drinking was significantly reduced at end treatment, but the reduction was equivalent across conditions. Post hoc analyses found that MI reduced drinking more rapidly than SOMI and SC and that increased change talk mediated the effects of MI relative to SOMI during the week immediately following the first session. Findings are discussed in the context of the pilot nature of the study and the relative absence of experimental tests of mechanisms of behavior change in SUD treatment research

Dismantling Motivational Interviewing: Effects On Initiation of Behavior Change Among Problem Drinkers Seeking Treatment.

Motivational interviewing (MI) is an efficacious treatment for alcohol use disorders. MI is thought to enhance motivation via a combination of 2 therapeutic strategies or active ingredients: 1 relational and 1 directional. The primary aim of this study was to examine MI\u27s hypothesized active ingredients using a dismantling design. Problem drinkers (N = 139) seeking treatment were randomized to 1 of 3 conditions: MI, relational MI without the directional elements labeled spirit-only MI (SOMI), or a nontherapy control condition and followed for 8 weeks. Those assigned to MI or SOMI received 4 sessions of treatment over 8 weeks. All participants significantly reduced their drinking by Week 8, but reductions were equivalent across conditions. The hypothesis that baseline motivation would significantly moderate condition effects on outcome was generally not supported. Failure to find support for MI\u27s hypothesized active ingredients is discussed in the context of the strengths and limitations of the study design