HUMAN SUBJECTS AND COGNITIVE AGING RESEARCH: A UNIQUE SOLUTION TO A PERENNIAL PROBLEM

A fundamental concern of cognitive aging researchers is to find a representative sample of healthy, older adults who are willing to participate in experimental research. There are essentially two methods for marshalling a sizable body of older research participants. One can solicit the aid of local community‐dwelling adults through civic and church‐related organizations. Alternatively, one can travel to specific locations where elderly people are likely to congregate, for example, a retirement community. In this article, we describe our experiences with these two methods of research‐participant recruitment. The processes involved in both securing and utilizing a local body of research volunteers are presented first. We then discuss two subject‐testing expeditions outside of the university environment that have been highly successful. In the final section, we contrast selected demographic characteristics of our local and off‐site research volunteers and discuss the implications of differences between these two populations for conducting research with aged people.     

Scaffolding Mathematics Remediation for Academically At-Risk Students Following Developmental Education Reform in Florida

The purpose of this qualitative study is to understand how educational scaffolding may explain changing patterns of student success in mathematics in the era of developmental education (DE or remediation) reform in Florida College System (FCS) institutions. Specifically, we apply the concept of scaffolding to underprepared FCS students who are at risk of dropping out or failing gateway courses (the first credit-bearing college-level class in a course sequence) because they lack the academic skills necessary to succeed in college-level coursework, particularly in mathematics. We present data from focus groups conducted at 10 FCS institutions, suggesting that a reduction of scaffolding in math remediation occurred in the areas of course sequencing, instruction, and coordination with academic support services following state-level policy changes. In light of these findings, we offer a discussion of practical recommendations for college administrators related to academic advising, instructional strategies in DE courses, coordination between developmental and college-level instructors, student success courses, and the integration of DE instruction with academic support. We also suggest directions for continued research on the effects of policy changes in the FCS and DE reform efforts across the country.     

EFFECTS OF AGE AND INSTRUCTIONS ON TEACHING OLDER ADULTS TO USE ELDERCOMM,AN ELECTRONIC BULLETIN BOARD SYSTEM

This study focused on how to train older adults to perform computer procedures. Young-old (aged 60 74 years) and old-old (aged 75 years and older) adults were instructed on how to use ELDERCOMM , an electronic bulletin board system using one of two types of text-based instructions. The first set of directions consisted of illustrated, step-by-step instructions (simple condition). The second set of directions included the same step-by-step instructions as in the first set, but explanatory information about how the bulletin board system worked was added before the     

Global output feedback tracking control for switched nonlinear systems with deferred prescribed performance

In this paper, the global output feedback tracking control is investigated for a class of switched nonlinear systems with time-varying system fault and deferred prescribed performance. The shifting function is introduced to improve the traditional prescribed performance control technique, remove the constraint condition on the initial value, and make the constraint bounds have more alternative forms. To estimate the unmeasured state variables and compensate the system fault, the switched dynamic gain extended state observer is constructed, which relaxes the traditional Lipschitz conditions on the nonlinear functions. Based on the proposed observer, by constructing the new Lyapunov function and using the backstepping method, the global robust output feedback controller is designed to make the output track the reference signal successfully, and after the adjustment time, the tracking error enters into the prescribed set. The stability of the system is analyzed by the average dwell time method. Finally, simulation results are given to illustrate the effectiveness of the proposed method.