The present experiment compared two methods of training a simple arm position using auditory feedback: capture and search. The participants were four right-handed female college students. During capture, auditory feedback was delivered by the experimenter after the participant moved along a single axis into the target position. During search, auditory feedback was produced by the computer after the participant left clicked a mouse inside the target location. The results of a multi-element design showed that participants performed more accurately during capture training than search training. Pre-training and post-training probes, during which no auditory feedback was provided, showed similar fluctuations in accuracy across probe types. A retention check, performed seven days after the final training session, showed higher accuracy scores for search than capture, across all four participants. These findings suggest that TAGteach should incorporate an approach similar to search training to improve training outcomes.

The number of wireless systems, services, and users are constantly increasing and therefore the bandwidth requirements have become higher. One of the most robust modulations is Orthogonal Frequency-Division Multiplexing (OFDM). It has been considered as an attractive solution for future broadband wireless communications. This dissertation investigates bit and power allocation, joint resource allocation, user scheduling, and limited feedback problem in multi-user OFDM systems. The following dissertation contributes to improved OFDM systems in the following manner. (1) A low complexity sub-carrier, power, and bit allocation algorithm is proposed. This algorithm has lower computational complexity and results in performance that is comparable to that of the existing algorithms. (2) Variations of the proportional fair scheduling scheme are proposed and analyzed. The proposed scheme improves system throughput and delay time, and achieves higher throughput without sacrificing fairness which makes it a better scheme in terms of efficiency and fairness. (3) A DCT feedback compression algorithm based on sorting is proposed. This algorithm uses sorting to increase the correlation between feedback channel quality information of frequency selective channels. The feedback overhead of system is successfully reduced.

Feedback is often necessary to provide guidance for future decisions, and factors relating to feedback, including the way feedback information is framed, how frequently it is provided, and the relevance of that feedback in relation to one's decision, have been designated as influential for decision making tendencies. Unfortunately, research on what produces the most effective feedback is mixed, and the relationship between these factors and resulting evaluative and behavioral outcomes in less clear. Four studies explored the relationship between feedback frame and frequency by addressing whether overall task feedback framed positively and receiving more frequent trial outcome feedback led to more positive performance evaluations and improvements in subsequent task performance (Studies 1A and 1B), how these evaluative and behavioral outcomes varied across different trial feedback frequency intervals (Study 2A), and whether more relevant trial feedback influenced the pattern of these results (Study 2B). Across the four studies, it was noted that the frequency of trial feedback was more influential for task performance outcomes, while the overall task feedback frame was more influential for performance evaluation outcomes. In addition, more relevant outcome feedback was seen to influence the relationship of feedback variables more for performance evaluations than task performance. Taken together, these studies provide some clarity as to how different types and presentations of feedback produce different evaluative and behavioral outcomes and show initial direction as to when framing task feedback and providing trial feedback more frequently can lead to better, more normatively correct decision making. Theoretical and practical implications, as well as reasons why effects were not consistent across studies, are also discussed.

User/relay selection is a simple technique that achieves spatial diversity in multiuser networks. However, for user/relay selection algorithms to make a selection decision, channel state information (CSI) from all cooperating users/relays is usually required at a central node. This requirement poses two important challenges. Firstly, CSI acquisition generates a great deal of feedback overhead (air-time) that could result in significant transmission delays. Secondly, the fed-back channel information is usually corrupted by additive noise. This could lead to transmission outages if the central node selects the set of cooperating relays based on inaccurate feedback information. Motivated by the aforementioned challenges, we propose a limited feedback user/relay selection scheme that is based on the theory of compressed sensing. Firstly, we introduce a limited feedback relay selection algorithm for a multicast relay network. The proposed algorithm exploits the theory of compressive sensing to first obtain the identity of the “strong” relays with limited feedback air-time. Following that, the CSI of the selected relays is estimated using minimum mean square error estimation without any additional feedback. To minimize the effect of noise on the fed-back CSI, we introduce a back-off strategy that optimally backs-off on the noisy received CSI. In the second part of the thesis, we propose a feedback reduction scheme for full-duplex relay-aided multiuser networks. The proposed scheme permits the base station (BS) to obtain channel state information (CSI) from a subset of strong users under substantially reduced feedback overhead. More specifically, we cast the problem of user identification and CSI estimation as a block sparse signal recovery problem in compressive sensing (CS). Using existing CS block recovery algorithms, we first obtain the identity of the strong users and then estimate their CSI using the best linear unbiased estimator (BLUE). Moreover, we derive the error covariance matrix of the post-detection noise to be used in the back-off strategy. In addition to this, we provide exact closed form expressions for the average maximum equivalent SNR at the destination user. The last part of the thesis treats the problem of user selection in a network MIMO setting. We propose a distributed user selection strategy that is based on a well known technique called semi-orthogonal user selection when the zero-forcing beamforming (ZFBF) is adopted. Usually this technique requires perfect channel state information at the transmitter (CSIT) which might not be available or need large feedback overhead. Instead, we propose a distributed user selection technique where no communication between base stations is needed. In order to reduce the feedback overhead, each user set a timer that is inversely proportional to his channel quality indicator (CQI). This technique will allow only the user with the highest CQI to feedback provided that the transmission time is shorter than the difference between his timer and the second strongest user timer, otherwise a collision will occur. In the case of collision, we propose another feedback strategy that is based on the theory of compressive sensing, where collision is allowed and each user encode its feedback using Gaussian codewords and feedback the combination at the same time with other users. We prove that the problem can be formulated as a block sparse recovery problem and that this approach is agnostic on the transmission time, thus it could be a good alternative to the timer approach when collision is dominant. Simulation results show that the proposed CS-based selection algorithms yield a rate performance that is close to the ones achieved when perfect CSI is available while consuming a small amount of feedback.

A high rate of instructional engagement is important to maximize progress in early intensive behavioral interventions (EIBI). Teachers responsible for eliciting instructional engagement may need additional support to maintain high rates of engagement. Literature suggests that goal setting and feedback is effective in increasing performance. the purpose of this study was to evaluate whether goal setting and group feedback would increase engagement in instructional activities related to the children’s goals. Results indicate that goal setting and group feedback was successful in increasing engagement in instructional activities. the results are discussed in the context of engagement, staff performance, group contingencies and performance feedback.

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English as a Foreign Language (EFL) teachers use different strategies to support language acquisition when teaching. This study focuses on one particular strategy: Oral Corrective Feedback (OCF). It is provided to support learners’ oral language skills, and takes numerous potential forms which can either be implemented implicitly and/or explicitly. According to many studies, recast is the type of OCF most commonly used by EFL teachers. Studies demonstrate however, that recast is the least effective approach for EFL learners’ uptake. The aim of this research study is to investigate how Swedish EFL teachers provide students with OCF. In addition, the intention is also to explore teachers’ and students’ perceptions of the usefulness of OCF for their skills development in English. The focus of this research study is on Swedish primary schools of grades 4-6. Two types of data-gathering methods were used in this study: interviews and observations. The results confirm that both explicit and implicit OCF was provided when observing the teachers’ approaches and strategies in classroom settings. Surprisingly, this research study reveals that recast was not favoured by the Swedish EFL teachers as they considered other types of OCF to be more beneficial to EFL classroom settings.

Feedback can be given in many different forms, and the type that is written and strives to either correct students written errors or support their overall writing ability is suitably enough referred to as written corrective feedback (WCF) of which there are two main types of: indirect and direct WCF. We know that second language writers meet many obstacles, be that lack of motivation and vocabulary or misspellings and phrasal issues; nonetheless, teachers thought processes about what type of feedback to give on what type of error is of importance for the continuation of the development of sound feedback approaches. Therefore, we intend to investigate English teachers perceptions on the WCF they give with the help of the following research questions: What are primary school English teachers’ perceptions about WCF in order to promote their ESL students writing development? What are primary school English teachers’ perceptions regarding their choice between written direct CF or written indirect CF on their ESL students written production?To investigate these questions we wrote an interview guide, and conducted interviews with seven teachers in 4th to 6th grade, asking about their perceptions on the development of writing in English as a second language and how they would describe their corrective feedback and their thought process on what type to give and when to give it on their student’s writing. Our findings showed that all teachers acknowledged two types of students in their ESL classroom: the high proficiency and the low proficiency. The low proficiency need more direct, clear and specific corrections on most of their writing whilst the high proficiency benefit from more indirect CF in order to make use of their metacognitive thinking skills. The findings also revealed that teachers choose to use indirect or direct CF based on the activity and whether the purpose is to learn grammar or not. If the focus is grammar, they would choose direct CF, and if it was to write a fictional story, they would give more indirect CF in order to not stifle the student’s creative process and “take the fun out of it”. Our study points to a need of more research within the field of feedback in general, since there is not much evidence showing what approaches are the most beneficial. Another issue is that there are practically no guidelines for teachers to follow, telling them what type to choose and for what activities. This is something for future research to dig deeper into.

Pragmatics “focuses on how people perform, interpret, and respond to language functions in a social context” (Taguchi, 2012, p.1), and therefore its development is key to the development of language competence. Pragmatics entails both linguistic knowledge to perform language functions (pragmalinguistics) and knowledge about the appropriateness of linguistic forms in a given social context (sociopragmatics) (Thomas, 1983). The acquisition of this skill has been shown to be one of the most difficult and latest acquired aspects of L2 learning (Bardovi-Harlig & Vellenga, 2012), and in this context, corrective feedback (information about the accuracy of learners’output), has been considered to be essential to the mastery of this knowledge. This study attempted to answer whether corrective feedback on L2 request and refusal forms provided through Face-to-Face (FF) or through Technology-Mediated (TM) modes can lead to an improvement in the learners’ performance in comprehension and production. Forty-four ELL students in three parallel intact classes were chosen to participate in the study. A Role-play test was used to collect production data and a multiple-choice discourse completion test was used to gather comprehension data. A mixed-model Analysis of Variance was conducted to examine the main and interaction effects of the treatment (corrective feedback), delivery mode (FF and TM), speech act type (request and refusal), and time (pre-test, post-test, and delayed post-test). The results demonstrated that CF led to improved performance in L2 pragmatics. Significant effects for corrective feedback were clear for both pragmatic comprehension and production, and there was no difference between comprehension and production improvement. Furthermore, the results showed that both FF and TM corrective feedback were effective modalities for improving pragmatic production while only TM delivery was effective in comprehending the target speech acts. The findings of the present study also suggest that CF effects were durable both in production and comprehension. The possibility of the effects of type of speech acts in influencing CF effects was generally rejected as CF improved comprehending and producing both speech acts significantly. In summary, the findings of the study generally support the application of CF and technology to the acquisition of second language pragmatic ability. / Graduate

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