A Method for Collaboratively Developing and Validating a Rubric

Assessing student learning outcomes relative to a valid and reliable standard that is academically-sound and employer-relevant presents a challenge to the scholarship of teaching and learning. In this paper, readers are guided through a method for collaboratively developing and validating a rubric that integrates baseline data collected from academics and professionals. The method addresses two additional goals: (1) to formulate and test a rubric as a teaching and learning protocol for a multi-section course taught by various instructors; and (2) to assure that students’ learning outcomes are consistently assessed against the rubric regardless of teacher or section. Steps in the process include formulating the rubric, collecting data, and sequentially analyzing the techniques used to validate the rubric and to insure precision in grading papers in multiple sections of a course

New Zealand Working For Families programme: Methodological considerations for evaluating MSD programmes

The methodological review is the second part of the evaluation research commissioned by the Ministry of Social Development (MSD) in 2005 to help in the preparation of the evaluation of the Working for Families (WFF) programme. This review enumerates the key evaluation questions identified by MSD as central to their policy concerns and considers how the features of WFF could affect evaluation. It details the methodological and data requirements that must be addressed in order to meet the four key evaluation objectives, namely: (1) tracking and evaluating the implementation and delivery of WFF (2) identifying changes in entitlement take-up and reasons for it (3) establishing the impact of WFF on employment-related outcomes (4) assessing WFF’s effect on net income and quality of life more generally. The methodological review complements the literature review by reviewing evaluations from around the world that are pertinent to WFF. An overview of evaluation methods is provided, concentrating on particular issues that arise within the WFF context. Section 2 focuses on implementation and delivery. Section 3 covers the issues related to take-up and entitlement and their evaluation. Section 4 discusses the evaluation methodologies that can be used in evaluating programmes such as WFF and introduces the data requirements they entail. Making work pay is the focus of section 5. Finally, section 6 examines hardship and poverty, living standards and wellbeing.

Do universal codon-usage patterns minimize the effects of mutation and translation error?

BACKGROUND: Do species use codons that reduce the impact of errors in translation or replication? The genetic code is arranged in a way that minimizes errors, defined as the sum of the differences in amino-acid properties caused by single-base changes from each codon to each other codon. However, the extent to which organisms optimize the genetic messages written in this code has been far less studied. We tested whether codon and amino-acid usages from 457 bacteria, 264 eukaryotes, and 33 archaea minimize errors compared to random usages, and whether changes in genome G+C content influence these error values. RESULTS: We tested the hypotheses that organisms choose their codon usage to minimize errors, and that the large observed variation in G+C content in coding sequences, but the low variation in G+U or G+A content, is due to differences in the effects of variation along these axes on the error value. Surprisingly, the biological distribution of error values has far lower variance than randomized error values, but error values of actual codon and amino-acid usages are actually greater than would be expected by chance. CONCLUSION: These unexpected findings suggest that selection against translation error has not produced codon or amino-acid usages that minimize the effects of errors, and that even messages with very different nucleotide compositions somehow maintain a relatively constant error value. They raise the question: why do all known organisms use highly error-minimizing genetic codes, but fail to minimize the errors in the mRNA messages they encode

Reviews

The Tolkien Relation: A Personal Inquiry. William Ready. Reviewed by Veronica M. S. Kennedy. The Tolkien Relation: A Personal Inquiry. William Ready. Reviewed by Bonniejean McGuire Christensen. Tolkien: A Look Behind The Lord of the Rings . Lin Carter. Reviewed by Sandra Miesel. Of Middle-earth and the Story of the Hobbit . Lin Carter. Reviewed by Richard V. Knight

Abundance of correctly folded RNA motifs in sequence space, calculated on computational grids

Although functional RNA molecules are known to be biased in overall composition, the effects of background composition on the probability of finding a particular active site by chance has received little attention. The probability of finding a particular motif has important implications both for understanding the distribution of functional RNAs in ancient and modern organisms with varying genome compositions and for tuning SELEX pools to optimize the chance of finding specific functions. Here we develop a new method for calculating the probability of finding a modular motif containing base-paired regions, and use a computational grid to fold several hundred million random RNA sequences containing the core elements of the isoleucine aptamer and the hammerhead ribozyme to estimate the probability that a sequence containing these structural elements will fold correctly when isolated from background sequences of different compositions. We find that the two motifs are most likely to be found in distinct regions of compositional space, and that the regions of greatest abundance are influenced by the probability of finding the conserved bases, finding the flanking helices, and folding, in that order of importance. Additionally, we can refine our estimates of the number of random sequences required for a 50% probability of finding an example of each site in unbiased random pools of length 100 to 4.1 × 10(9) for the isoleucine aptamer and 1.6 × 10(10) for the hammerhead ribozyme. These figures are consistent with the facile recovery of these motifs from SELEX experiments

Detecting coevolution without phylogenetic trees? Tree-ignorant metrics of coevolution perform as well as tree-aware metrics

<p>Abstract</p> <p>Background</p> <p>Identifying coevolving positions in protein sequences has myriad applications, ranging from understanding and predicting the structure of single molecules to generating proteome-wide predictions of interactions. Algorithms for detecting coevolving positions can be classified into two categories: tree-aware, which incorporate knowledge of phylogeny, and tree-ignorant, which do not. Tree-ignorant methods are frequently orders of magnitude faster, but are widely held to be insufficiently accurate because of a confounding of shared ancestry with coevolution. We conjectured that by using a null distribution that appropriately controls for the shared-ancestry signal, tree-ignorant methods would exhibit equivalent statistical power to tree-aware methods. Using a novel t-test transformation of coevolution metrics, we systematically compared four tree-aware and five tree-ignorant coevolution algorithms, applying them to myoglobin and myosin. We further considered the influence of sequence recoding using reduced-state amino acid alphabets, a common tactic employed in coevolutionary analyses to improve both statistical and computational performance.</p> <p>Results</p> <p>Consistent with our conjecture, the transformed tree-ignorant metrics (particularly Mutual Information) often outperformed the tree-aware metrics. Our examination of the effect of recoding suggested that charge-based alphabets were generally superior for identifying the stabilizing interactions in alpha helices. Performance was not always improved by recoding however, indicating that the choice of alphabet is critical.</p> <p>Conclusion</p> <p>The results suggest that t-test transformation of tree-ignorant metrics can be sufficient to control for patterns arising from shared ancestry.</p