No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

The present study attempts to demonstrate both mediated facilitation and interference in the learning and retention of single lists of paired-associates under conditions analogous to the standard retroaction paradigms. Conditions for intra-list facilitation (Positive Condition) are established by pairing identical responses with pairs of associatively related stimuli (Lists A-B/A’-B). Conditions for intra-list interference (Negative Condition) are established by pairing different responses with pairs of associatively related stimuli (List; A-B/A’-C). Two experiments were conducted. In Experiment I, homogeneous lists of eight paired-associates with pairs of stimulus terms having three degrees of associative relatedness were used. The three degrees of associative relatedness were: (1) first associates, (2) second associates, and (3) a non- related or List-Control level. This resulted in a 3 x 2 factorial experiment: two conditions (Positive and Negative) by three degrees of stimulus pair relatedness. In Experiment I, seventy-two undergraduate females received one study- trial and six learning trials. All subjects (Ss) returned forty-eight hours later and received ten recall trials and then relearned the lists to a criterion of one errorless trial. The Immediate-Recall Method for estimating the level of original learning was used in Experiment I. In Experiment II, eighty undergraduate males received the same procedures as Ss in Experiment I, except that five learning trials were administered so that the Projection Method for estimating the level of original learning used in Experiment II could be compared directly with the Immediate-Recall Method employed in Experiment I. In Experiment II, only the first association Positive and first association Negative Conditions were used. Facilitation and interference were demonstrated in the learning of A-B/A’-B and A-B/A’-C lists, respectively. Degree of association was not an effective factor in the production of either facilitation or interference. The effectiveness of experimental manipulations was further demonstrated by the finding that S-R pairs which appeared in the lists of the Positive Conditions were learned significantly faster than identical S-R pairs which appeared in the lists of the Negative Conditions. A direct index of mediated interference was provided by the greater than chance frequency of predicted errors (i.e., in List A-B/A’-C, predicted errors are of the type A-C or A’-B) found in the learning of the lists of the Negative Conditions. The experimental manipulations responsible for facilitation and interference in the learning of the lists did not affect retention of the lists. Recall was high in all conditions of both experiments. Relearning to a criterion of one errorless trial did result in significantly faster relearning in the Positive Conditions of both experiments. Significant differences in relearning were not obtained when relearning to the level of original learning was the criterion. An analysis of original learning, recall and relearning in terms of the Two-Stage analysis of verbal learning indicated that the primary focus of facilitation and interference was the second or associative stage of learning. Comparisons of the Immediate-Recall and Projection methods showed that the two methods resulted in almost identical estimates of original learning. The mediation hypothesis of intra-list transfer is discussed and compared with the stimulus-generalisation hypothesis of transfer effects. The mediational-linking hypothesis is presented as the most adequate explanation of intra-list interference. The common-concept hypothesis is offered as the most adequate explanation of intra-list facilitation in the present study. / This thesis was digitized as part of a project begun in 2014 to increase the number of Duke psychology theses available online. The digitization project was spearheaded by Ciara Healy.

The purpose of this study was to determine whether the transfer of training would affect the achievement and retention scores of subjects learning selected tennis and badminton skills. This study was intended to establish the most beneficial teaching progression for tennis and badminton skills.

This project evaluated the metal transfer behaviour of the variable polarity (VP) GMAW process. Analysis was performed using high speed video that was synchronised with high speed data acquisition. Melting rate measurements were found to be very dependent on current waveform, polarity, and droplet size, and metal transfer if it occurred, for each waveform period. The transient conditions of current waveform and metal transfer produced rapid changes in arc behaviour which influenced the melting at the electrode tip and growing droplet. The concentrated melting theory was developed to explain the significant increase in electrode extension burnoff and droplet growth rate that occurred at short EN time as a function of current, and during EP peak pulse when the pre-pulse droplet volume was small. The highest electrode extension burnoff and droplet growth rate occurred when the arc was permitted to climb over the solid electrode tip producing rapid concentrated melting. Likewise, large molten droplets were found to promote a negative electrode extension burnoff and a decreased droplet growth rate. The arc rooted on large droplets providing additional heating but limited electrode melting. The droplet burnoff rate (DBR) method was developed and found to yield good experimental measurements for the arc and resistive heating coefficients used in a 2nd order melting rate equation developed for a complex waveform process, like VP-GMAW. For the EN period, the EN time affected the melting rate as a function of EN current. The greater melting rate that occurred at low EN time was measured by the changes in the resistive heating coefficient. Concentrated arc melting of the electrode extension at low EN time caused the slope of the burnoff diagram to increase, which represented the resistive heating coefficient. The melting rate of the EP pulse was related to the pre-pulse droplet volume. Large pre-pulse droplets decreased the arc heating coefficient, which could be negative, which meant the electrode extension was increasing and the arc length was decreasing in that waveform period. VP-GMAW power supplies offered stable operation for welding sheet structures on both carbon steel and stainless steel. Higher travel speeds were required as the %EN of the waveform increased to produce acceptable constant deposit area fusion. Welding speeds were up to 300% higher with VP-GMAW compared to the GMAW-P process when welding lap joints on 1.8 mm thick material with a 1.8 mm gap. VP-GMAW heat input was up to 47% less than GMAW-P for the same melting rate.