title: Effects of sample-set size on delayed-matching-to-sample

authors: Adamson, Coreen

abstract: In a series of experiments the discriminative performance of university students was assessed using a Delayed-Matching-to-Sample task. White disks, presented on computer screens, served as stimuli. For the general DMTS task, used here, a sample stimulus was presented to the participant. After a variable delay (0.05, 4, 8 or 16 s) two comparison stimuli were presented on the computer screen. One of these comparison stimuli was the same size as the sample stimulus (matching comparison) and the other was slightly larger or smaller than the sample stimulus (non-matching comparison). The sample stimuli were not intended to appear as comparison stimuli and for each of the sample stimuli there were two possible non-matching comparison sample stimuli, one larger and one smaller than the sample stimulus. The first three experiments showed that it was possible to use a titration procedure to get similar levels of performance across participants, at zero delay. During the titration procedure the size of the non-matching comparison stimuli was changed, for each participant until they were 100% correct at 0.05 s delay. The first two of these experiments also showed that there were generally only small decreases in performance as the delay between the presentation of the sample stimuli and the comparison stimuli was increased. The fourth experiment showed that performance on the DMTS task did not change when feedback was given for correct responses. The fifth and sixth experiments showed that as the number of sample stimuli used in the DMTS task, was increased there was a systematic decrease in a, a measure of discrimination at zero delay, but no systematic change in b, a measure of the rate of decrement in performance with increasing delay. It was not clear whether this decrease in a was a product of the increase in the sample-set size or of the associated decrease in the correspondence of sample stimuli on consecutive trial pairs. Experiment 7 suggested that, when the number of sample stimuli used for the DMTS was held constant and the ratio of corresponding to non-corresponding trial pairs was varied, there was no systematic change in either a or b. However, the results of this experiment were confounded by a ceiling effect and so a different procedure was required. The procedure used for the remaining experiments was a two-sample DMTS task, where the sample stimuli were also used as comparison stimuli. This type of DMTS task is similar to that typically used in discrimination tasks with animal subjects. The eighth and ninth experiments were designed to investigate whether this type of procedure could be successfully used with human participants and found that it could be. Experiment 10 also used this type of two-sample DMTS task to investigate the effect of decreasing the ratio of corresponding to non-corresponding trial pairs. It was found that, when there was no ceiling effect, varying the ratio of corresponding to non-corresponding trial pairs did not result in a systematic change in either a or b as in Experiment 7. These results are discussed in terms of the effects of range, sample-set size and of the ratio of corresponding to non-corresponding trial pairs on human performance on DMTS.

text: Effects of sample-set size on delayed-matching-to-sample In a series of experiments the discriminative performance of university students was assessed using a Delayed-Matching-to-Sample task. White disks, presented on computer screens, served as stimuli. For the general DMTS task, used here, a sample stimulus was presented to the participant. After a variable delay (0.05, 4, 8 or 16 s) two comparison stimuli were presented on the computer screen. One of these comparison stimuli was the same size as the sample stimulus (matching comparison) and the other was slightly larger or smaller than the sample stimulus (non-matching comparison). The sample stimuli were not intended to appear as comparison stimuli and for each of the sample stimuli there were two possible non-matching comparison sample stimuli, one larger and one smaller than the sample stimulus. The first three experiments showed that it was possible to use a titration procedure to get similar levels of performance across participants, at zero delay. During the titration procedure the size of the non-matching comparison stimuli was changed, for each participant until they were 100% correct at 0.05 s delay. The first two of these experiments also showed that there were generally only small decreases in performance as the delay between the presentation of the sample stimuli and the comparison stimuli was increased. The fourth experiment showed that performance on the DMTS task did not change when feedback was given for correct responses. The fifth and sixth experiments showed that as the number of sample stimuli used in the DMTS task, was increased there was a systematic decrease in a, a measure of discrimination at zero delay, but no systematic change in b, a measure of the rate of decrement in performance with increasing delay. It was not clear whether this decrease in a was a product of the increase in the sample-set size or of the associated decrease in the correspondence of sample stimuli on consecutive trial pairs. Experiment 7 suggested that, when the number of sample stimuli used for the DMTS was held constant and the ratio of corresponding to non-corresponding trial pairs was varied, there was no systematic change in either a or b. However, the results of this experiment were confounded by a ceiling effect and so a different procedure was required. The procedure used for the remaining experiments was a two-sample DMTS task, where the sample stimuli were also used as comparison stimuli. This type of DMTS task is similar to that typically used in discrimination tasks with animal subjects. The eighth and ninth experiments were designed to investigate whether this type of procedure could be successfully used with human participants and found that it could be. Experiment 10 also used this type of two-sample DMTS task to investigate the effect of decreasing the ratio of corresponding to non-corresponding trial pairs. It was found that, when there was no ceiling effect, varying the ratio of corresponding to non-corresponding trial pairs did not result in a systematic change in either a or b as in Experiment 7. These results are discussed in terms of the effects of range, sample-set size and of the ratio of corresponding to non-corresponding trial pairs on human performance on DMTS.

year: 2002

title: Protean and Boundaryless Career Attitudes in New Zealand Workers

authors: Morrell, Heather Rebecca

subjects: Protean Career

abstract: This study explored protean and boundaryless career attitudes in a sample of New Zealand workers. Recent changes to both organisational and societal structures have significantly altered how careers are acted out. Employees are now required to be flexible and adaptable, and can no longer rely on organisations to manage their career development. Individuals have had to become more open to networking and collaboration across organisational boundaries, and to working for multiple employers. These changes have resulted in two key career models emerging in the research – the protean career and the boundaryless career. The protean career is conceptualised as involving a self-directed approach to career management combined with a values-driven approach to career management. The boundaryless career is conceptualised as involving both a boundaryless mindset,i.e. wanting to work across organisational boundaries, and a mobility preference,i.e. the desire to work for more than one employer. The purpose of this study was to investigate how demographic and personality variables relate to protean and boundaryless career attitudes in New Zealand workers. Measures of the protean career attitude and the boundaryless career attitude were included in a survey, along with demographic variables, personality variables and career variables. The survey was sent to 1300 New Zealand workers via four organisations and 226 completed responses were received. Overall, demographic variables were found to relate less strongly to protean and boundaryless career attitudes than was expected. Education level was found to be the most predictive demographic variable, while age and gender were related only to one of the protean career attitudes. Overall, proactive personality was found to be the strongest predictor of three out of the four career attitudes. Supplementary analyses found that individuals on a casual employment contract had higher levels of one of the boundaryless career attitudes (boundaryless mindset) than those on a permanent contract, and there were some differences between employment sector groups on one of the boundaryless career attitudes (boundaryless mindset) and one of the protean career attitudes (self-directed career management). Values-driven career management was negatively correlated with employer, occupational and geographic mobility, and no other relationships were found between any of the career attitudes and mobility. This research has significantly added to our understanding of protean and boundaryless career attitudes in the New Zealand context. The findings highlight that protean and boundaryless careers are made up of separate but related constructs that are associated with demographic and personality variables in distinct ways. In particular, this study has shown that while differences between genders have been assumed to exist, such differences do not necessarily occur. Furthermore, individuals with higher levels of education were shown to be more likely to hold certain protean and boundaryless career attitudes. This study highlighted that mobility is not synonymous with protean and boundaryless careers as has been previously assumed in the literature. It has addressed a number of key areas that were highlighted as needing further research, such as potential gender differences in career attitudes,and it has also opened up several areas for future exploration.

text: Protean and Boundaryless Career Attitudes in New Zealand Workers This study explored protean and boundaryless career attitudes in a sample of New Zealand workers. Recent changes to both organisational and societal structures have significantly altered how careers are acted out. Employees are now required to be flexible and adaptable, and can no longer rely on organisations to manage their career development. Individuals have had to become more open to networking and collaboration across organisational boundaries, and to working for multiple employers. These changes have resulted in two key career models emerging in the research – the protean career and the boundaryless career. The protean career is conceptualised as involving a self-directed approach to career management combined with a values-driven approach to career management. The boundaryless career is conceptualised as involving both a boundaryless mindset,i.e. wanting to work across organisational boundaries, and a mobility preference,i.e. the desire to work for more than one employer. The purpose of this study was to investigate how demographic and personality variables relate to protean and boundaryless career attitudes in New Zealand workers. Measures of the protean career attitude and the boundaryless career attitude were included in a survey, along with demographic variables, personality variables and career variables. The survey was sent to 1300 New Zealand workers via four organisations and 226 completed responses were received. Overall, demographic variables were found to relate less strongly to protean and boundaryless career attitudes than was expected. Education level was found to be the most predictive demographic variable, while age and gender were related only to one of the protean career attitudes. Overall, proactive personality was found to be the strongest predictor of three out of the four career attitudes. Supplementary analyses found that individuals on a casual employment contract had higher levels of one of the boundaryless career attitudes (boundaryless mindset) than those on a permanent contract, and there were some differences between employment sector groups on one of the boundaryless career attitudes (boundaryless mindset) and one of the protean career attitudes (self-directed career management). Values-driven career management was negatively correlated with employer, occupational and geographic mobility, and no other relationships were found between any of the career attitudes and mobility. This research has significantly added to our understanding of protean and boundaryless career attitudes in the New Zealand context. The findings highlight that protean and boundaryless careers are made up of separate but related constructs that are associated with demographic and personality variables in distinct ways. In particular, this study has shown that while differences between genders have been assumed to exist, such differences do not necessarily occur. Furthermore, individuals with higher levels of education were shown to be more likely to hold certain protean and boundaryless career attitudes. This study highlighted that mobility is not synonymous with protean and boundaryless careers as has been previously assumed in the literature. It has addressed a number of key areas that were highlighted as needing further research, such as potential gender differences in career attitudes,and it has also opened up several areas for future exploration.

year: 2010

title: From assimilation to biculturalism: Changing patterns in Maori-Pakeha relationships

authors: Thomas, David R.

subjects: New Zealand

abstract: This chapter examines the changing patterns of inter-ethnic relationships among Maori and Pakeha in New Zealand, specifically the moves from assimilation towards biculturalism. The impact of recent debate about the Treaty of Waitangi is described and examples of bicultural policies and their consequences are outlined.

text: From assimilation to biculturalism: Changing patterns in Maori-Pakeha relationships This chapter examines the changing patterns of inter-ethnic relationships among Maori and Pakeha in New Zealand, specifically the moves from assimilation towards biculturalism. The impact of recent debate about the Treaty of Waitangi is described and examples of bicultural policies and their consequences are outlined.

year: 1996