Published just over a half century ago, Schedules of Reinforcement (SOR) (Ferster & Skinner, 1957) marked the seminal empirical contribution of the book’s second author and ushered in an era of research on behavior–environment relationships. This article traces the origins of both the methods and the data presented in SOR, and its legacy within experimental psychology. The operant methodology o...

yes. The presence of arborized crystals (ferning) in amniotic fluid is both sensitive (74%-100%) and specific (77%-100%) for diagnosing rupture of membranes in laboring women who report loss of fluid (strength of recommendation [SOR]: A, multiple prospective cohort studies). However, it is much less sensitive and specific for women with fluid loss who aren’t in labor (SOR: B, 1 prospective coho...

Beta-blockers (class II antiarrhythmics) reduce sudden death and total mortality in patients with heart failure (strength of recommendation [SOR]: A, based on systematic reviews of randomized controlled trials). Amiodarone (class III) may reduce sudden death in heart failure (SOR: B, extrapolation from randomized controlled trials), but evidence is weak that it reduces total mortality, and it h...

Perform an ankle-arm index (AAI, or ankle-brachial index) test to evaluate for peripheral artery disease (PAD) (strength of recommendation [SOR]: B, cohort studies). If the test detects PAD, recommend steps to modify cardiovascular risk factors (SOR: B, extrapolation from randomized clinical trials [RCTs]). Additional vascular diagnostic evaluation is not indicated, because no evidence suggests...

The paper describes, discusses, and numerically illustrates the method for obtaining a priori estimates of the optimum relaxation factor in the SOR iteration method. The computational strategy of this method uses the so-called Sigma-SOR algorithm based on the theoretical result proven in the paper. The method presented is especially efficient for problems with slowly convergent iteration proces...

six to 8 weeks after the start of levothyroxine therapy you should reexamine patients and measure their serum thyroidstimulating hormone (TsH) (strength of recommendation [sor]: c, common practice and expert opinion). If thyroid function is normal at that time, examine the patient and measure serum TsH again in 4 to 6 months because clearance of levothyroxine increases in the euthyroid (normal)...

nystatin oral suspension is a safe firstline therapy; fluconazole is more effective (strength of recommendation [sor]: B, 1 small randomized controlled trial [rCT]) but has not been approved by the Food and Drug Administration (FDA) for use in immunocompetent infants. Miconazole oral gel is also more effective than nystatin suspension, but is not commercially available in the united states (sor...

BACKGROUND Reported rates of acute hepatitis B are high in many former Soviet Union republics and modes of transmission are not well defined. METHODS Two case-control studies were undertaken in Moldova to identify risk factors for acute hepatitis B in people aged 2-15 years (children) and > or =15 years (adults). Serologically confirmed acute hepatitis B cases occurring between 1 January 1994...