Key considerations to improve the normalization, interpretation and reproducibility of morbidity data in mammalian models of viral disease.

Viral pathogenesis and therapeutic screening studies that utilize small mammalian models rely on the accurate quantification and interpretation of morbidity measurements, such as weight and body temperature, which can vary depending on the model, agent and/or experimental design used. As a result, morbidity-related data are frequently normalized within and across screening studies to aid with their interpretation. However, such data normalization can be performed in a variety of ways, leading to differences in conclusions drawn and making comparisons between studies challenging. Here, we discuss variability in the normalization, interpretation, and presentation of morbidity measurements for four model species frequently used to study a diverse range of human viral pathogens - mice, hamsters, guinea pigs and ferrets. We also analyze findings aggregated from influenza A virus-infected ferrets to contextualize this discussion. We focus on serially collected weight and temperature data to illustrate how the conclusions drawn from this information can vary depending on how raw data are collected, normalized and measured. Taken together, this work supports continued efforts in understanding how normalization affects the interpretation of morbidity data and highlights best practices to improve the interpretation and utility of these findings for extrapolation to public health contexts.

Baseline measurement of running away among youth in foster care.

The current study evaluated the use of various behavioral measures of running away with regard to (a) the differential utility of interval- versus event-based measures, (b) the differential utility of rate versus duration measures, (c) the utility of correcting for occurrence opportunity, and (d) the influence of unit of analysis (i.e., single-subject vs. grouped data). Seven different baseline measures were calculated for 84 runaways, and a unit-size analysis was conducted by constructing groups of various sizes from the original sample. An expert panel evaluated the suitability of the baseline measures for treatment evaluation. Results demonstrate the utility of evaluating duration-based measures and correcting for occurrence opportunity. Results also indicate that single-subject baselines may often be unacceptable for treatment evaluations, regardless of the type of measure selected for use.

Teaching math skills to at-risk students using home-based peer tutoring.

Home-based peer tutoring was used to teach math skills to 4 girls with deficits in mathematics and histories of abuse or neglect. Girls living in the same home formed tutoring dyads, and each participant served as both the peer tutor and the tutee during the course of the study. At the initiation of the tutoring intervention, an expert tutor provided multiple 3-min tutoring sessions to the designated peer tutor on three or four mathematics skills. The peer tutor concurrently provided 3-min tutoring sessions on the same skills to the tutee using a multiple baseline design. Results showed that participants improved their performance on all target skills. Additional interventions were implemented for some skills to improve accuracy further. Maintenance tests were also administered after 3 to 5 months of no practice on the skills. Results showed that tutors and tutees maintained their accuracy on 7 of the 12 skills assessed.

The effects of cumulative practice on mathematics problem solving.

This study compared three different methods of teaching five basic algebra rules to college students. All methods used the same procedures to teach the rules and included four 50-question review sessions interspersed among the training of the individual rules. The differences among methods involved the kinds of practice provided during the four review sessions. Participants who received cumulative practice answered 50 questions covering a mix of the rules learned prior to each review session. Participants who received a simple review answered 50 questions on one previously trained rule. Participants who received extra practice answered 50 extra questions on the rule they had just learned. Tests administered after each review included new questions for applying each rule (application items) and problems that required novel combinations of the rules (problem-solving items). On the final test, the cumulative group outscored the other groups on application and problem-solving items. In addition, the cumulative group solved the problem-solving items significantly faster than the other groups. These results suggest that cumulative practice of component skills is an effective method of training problem solving.