Pairing Repeated Reading and Systematic Error Correction: Impact on Fluency of 18 Year Old Students on a Small Caribbean Island

This study investigates the impact of a combined treatment of Systematic Error Correction and Repeated Reading on reading rate and errors for 18 year olds with undiagnosed reading difficulties on a Caribbean Island. In addition to direct daily measures of reading accuracy, the Reading Self Perception Scale was administered to determine whether the intervention was associated with changes in the way the student perceives himself as a reader.

Empirical study of exchange rates in Brazil, Canada and the Caribbean

This dissertation examines the monetary models of exchange rate determination for Brazil, Canada, and two countries in the Caribbean, namely, the Dominican Republic and Jamaica. With the exception of Canada, the others adopted the floating regime during the past ten years.^ The empirical validity of four seminal models in exchange rate economics were determined. Three of these models were entirely classical (Bilson and Frenkel) or Keynesian (Dornbusch) in nature. The fourth model (Real Interest Differential Model) was a mixture of the two schools of economic theory.^ There is no clear empirical evidence of the validity of the monetary models. However, the signs of the coefficients of the nominal interest differential variable were as predicted by the Keynesian hypothesis in the case of Canada and as predicted by the Chicago theorists in the remaining countries. Moreover, in case of Brazil, due to hyperinflation, the exchange rate is heavily influenced by domestic money supply.^ I also tested the purchasing power parity (PPP) for this same set of countries. For both the monetary as well as the PPP hypothesis, I tested for co-integration and applied ordinary least squares estimation procedure. The error correction model was also used for the PPP model, to determine convergence to equilibrium.^ The validity of PPP is also questionable for my set of countries. Endogeinity among the regressors as well as the lack of proper price indices are the contributing factors. More importantly, Central Bank intervention negate rapid adjustment of price and exchange rates to their equilibrium value. However, its forecasting capability for the period 1993-1994 is superior compared to the monetary models in two of the four cases.^ I conclude that in spite of the questionable validity of these models, the monetary models give better results in the case of the "smaller" economies like the Dominican Republic and Jamaica where monetary influences swamp the other determinants of exchange rate. ^

Effects of special educator peer coaching on general educator effectiveness in inclusive classroom settings

This dissertation investigated the effects of a peer coaching relationship between a special education teacher and two general education teachers. More specifically, a two-tier multiple baseline design across subjects was used to evaluate the effects of peer coaching on the general education teachers' use of effective instructional practices (EIPs) and subsequent effects on the engagement rate and academic performance of students with and without disabilities. The peer coaching process included modeling, direct support, and feedback on the use of effective instructional practices including getting student attention, giving specific directions, asking specific questions with wait time, contingent positive reinforcement, positive error correction, precorrection, prompting, and proximity control. A 30-second partial interval recording procedure was used to observe the general education teachers' use of effective instructional practices and student engagement rates. Student participants' academic performance was measured using weekly quizzes. ^ Peer coaching resulted in an overall increase in the teachers' use of EIPs. One general education teacher had a 30% increase in average EIP use from 46% during the baseline phase to 76% during intervention. Student engagement for her two student participants with and without disabilities indicated an increase from 54% to 69% and from 47% to 65% respectively. Results for the second general education teacher indicated a 34% increase in average EIP use from 55% during the baseline to 89% during intervention. Student engagement for the two student participants with and without disabilities in her class increased from 48% to 83% and from 29% to 71% respectively. Student academic performance showed a small increase. In follow-up observations, the effects of peer coaching on teacher use of EIPs and student engagement and academic performance were maintained. ^ The results of this study suggest that using peer coaching to support general education teachers can be an effective method to improve the educational outcomes of students with and without disabilities in general education. Further research is needed to investigate the effects of peer coaching with other special and general educator partnerships and other student participants. ^

Effects of repeated readings on reading abilities of English language learners with specific learning disabilities

This study investigated the effects of repeated readings on the reading abilities of 4, third-, fourth-, and fifth-grade English language learners (ELLs) with specific learning disabilities (SLD). A multiple baseline probe design across subjects was used to explore the effects of repeated readings on four dependent variables: reading fluency (words read correctly per minute; wpm), number of errors per minute (epm), types of errors per minute, and answer to literal comprehension questions. Data were collected and analyzed during baseline, intervention, generalization probes, and maintenance probes. Throughout the baseline and intervention phases, participants read a passage aloud and received error correction feedback. During baseline, this was followed by fluency and literal comprehension question assessments. During intervention, this was followed by two oral repeated readings of the passage. Then the fluency and literal comprehension question assessments were administered. Generalization probes followed approximately 25% of all sessions and consisted of a single reading of a new passage at the same readability level. Maintenance sessions occurred 2-, 4-, and 6-weeks after the intervention ended. The results of this study indicated that repeated readings had a positive effect on the reading abilities of ELLs with SLD. Participants read more wpm, made fewer epm, and answered more literal comprehension questions correctly. Additionally, on average, generalization scores were higher in intervention than in baseline. Maintenance scores were varied when compared to the last day of intervention, however, with the exception of the number of hesitations committed per minute maintenance scores were higher than baseline means. This study demonstrated that repeated readings improved the reading abilities of ELLs with SLD and that gains were generalized to untaught passages. Maintenance probes 2-, 4-, and 6- weeks following intervention indicated that mean reading fluency, errors per minute, and correct answers to literal comprehensive questions remained above baseline levels. Future research should investigate the use of repeated readings in ELLs with SLD at various stages of reading acquisition. Further, future investigations may examine how repeated readings can be integrated into classroom instruction and assessments.

Effects of Repeated Readings on Reading Abilities of English Language Learners with Specific Learning Disabilities

This study investigated the effects of repeated readings on the reading abilities of 4, third-, fourth-, and fifth-grade English language learners (ELLs) with specific learning disabilities (SLD). A multiple baseline probe design across subjects was used to explore the effects of repeated readings on four dependent variables: reading fluency (words read correctly per minute; wpm), number of errors per minute (epm), types of errors per minute, and answer to literal comprehension questions. Data were collected and analyzed during baseline, intervention, generalization probes, and maintenance probes. Throughout the baseline and intervention phases, participants read a passage aloud and received error correction feedback. During baseline, this was followed by fluency and literal comprehension question assessments. During intervention, this was followed by two oral repeated readings of the passage. Then the fluency and literal comprehension question assessments were administered. Generalization probes followed approximately 25% of all sessions and consisted of a single reading of a new passage at the same readability level. Maintenance sessions occurred 2-, 4-, and 6-weeks after the intervention ended. The results of this study indicated that repeated readings had a positive effect on the reading abilities of ELLs with SLD. Participants read more wpm, made fewer epm, and answered more literal comprehension questions correctly. Additionally, on average, generalization scores were higher in intervention than in baseline. Maintenance scores were varied when compared to the last day of intervention, however, with the exception of the number of hesitations committed per minute maintenance scores were higher than baseline means. This study demonstrated that repeated readings improved the reading abilities of ELLs with SLD and that gains were generalized to untaught passages. Maintenance probes 2-, 4-, and 6- weeks following intervention indicated that mean reading fluency, errors per minute, and correct answers to literal comprehensive questions remained above baseline levels. Future research should investigate the use of repeated readings in ELLs with SLD at various stages of reading acquisition. Further, future investigations may examine how repeated readings can be integrated into classroom instruction and assessments.

Space time coding for polynomial phase modulated signals

Polynomial phase modulated (PPM) signals have been shown to provide improved error rate performance with respect to conventional modulation formats under additive white Gaussian noise and fading channels in single-input single-output (SISO) communication systems. In this dissertation, systems with two and four transmit antennas using PPM signals were presented. In both cases we employed full-rate space-time block codes in order to take advantage of the multipath channel. For two transmit antennas, we used the orthogonal space-time block code (OSTBC) proposed by Alamouti and performed symbol-wise decoding by estimating the phase coefficients of the PPM signal using three different methods: maximum-likelihood (ML), sub-optimal ML (S-ML) and the high-order ambiguity function (HAF). In the case of four transmit antennas, we used the full-rate quasi-OSTBC (QOSTBC) proposed by Jafarkhani. However, in order to ensure the best error rate performance, PPM signals were selected such as to maximize the QOSTBC’s minimum coding gain distance (CGD). Since this method does not always provide a unique solution, an additional criterion known as maximum channel interference coefficient (CIC) was proposed. Through Monte Carlo simulations it was shown that by using QOSTBCs along with the properly selected PPM constellations based on the CGD and CIC criteria, full diversity in flat fading channels and thus, low BER at high signal-to-noise ratios (SNR) can be ensured. Lastly, the performance of symbol-wise decoding for QOSTBCs was evaluated. In this case a quasi zero-forcing method was used to decouple the received signal and it was shown that although this technique reduces the decoding complexity of the system, there is a penalty to be paid in terms of error rate performance at high SNRs.

Quasi-Orthogonal Space-Time Block Coding Using Polynomial Phase Modulation

Recently, polynomial phase modulation (PPM) was shown to be a power- and bandwidth-efficient modulation format. These two characteristics are in high demand nowadays specially in mobile applications, where devices with size, weight, and power (SWaP) constraints are common. In this paper, we propose implementing a full-diversity quasiorthogonal space-time block code (QOSTBC) using polynomial phase signals as modulation format. QOSTBCs along with PPM are used in order to improve the power efficiency of communication systems with four transmit antennas. We obtain the optimal PPM constellations that ensure full diversity and maximize the QOSTBC's minimum coding gain distance. Simulation results show that by using QOSTBCs along with a properly selected PPM constellation, full diversity in flat fading channels and thus low BER at high signal-to-noise ratios (SNR) can be ensured. More importantly, it is also shown that QOSTBCs using PPM achieve a better error performance than those using conventional modulation formats.