The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Guido H E Gendolla - One of the best experts on this subject based on the ideXlab platform.
-
Task Difficulty effects on cardiac activity
Psychophysiology, 2008Co-Authors: Michael Richter, Antonia Friedrich, Guido H E GendollaAbstract:An experiment with 64 participants manipulated Task Difficulty and assessed cardiac reactivity in active coping over four levels of demand. Participants performed a memory Task while preejection period, heart rate, and blood pressure were assessed. In accordance with the theoretical predictions of R. A. Wright’s (1996) integration of motivational intensity theory (J. W. Brehm & E. A. Self, 1989) with Obrist’s active coping approach (P. A. Obrist, 1981), preejection period and systolic blood pressure reactivity increased with Task Difficulty across the first three Difficulty levels. On the fourth Difficulty levelFwhere success was impossibleFreactivity of both preejection period and systolic blood pressure were low. These findings provide the first clear evidence for the notion of Wright’s integrative model that energy mobilization in active coping is mediated by beta-adrenergic impact on the heart. Descriptors: Task Difficulty, Beta-adrenergic response, Cardiovascular reactivity, Active coping
-
Task Difficulty effects on cardiac activity.
Psychophysiology, 2008Co-Authors: Michael Richter, Antonia Friedrich, Guido H E GendollaAbstract:An experiment with 64 participants manipulated Task Difficulty and assessed cardiac reactivity in active coping over four levels of demand. Participants performed a memory Task while preejection period, heart rate, and blood pressure were assessed. In accordance with the theoretical predictions of R. A. Wright's (1996) integration of motivational intensity theory (J. W. Brehm & E. A. Self, 1989) with Obrist's active coping approach (P. A. Obrist, 1981), preejection period and systolic blood pressure reactivity increased with Task Difficulty across the first three Difficulty levels. On the fourth Difficulty level-where success was impossible-reactivity of both preejection period and systolic blood pressure were low. These findings provide the first clear evidence for the notion of Wright's integrative model that energy mobilization in active coping is mediated by beta-adrenergic impact on the heart.
-
Incentive value, unclear Task Difficulty, and cardiovascular reactivity in active coping.
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 2006Co-Authors: Michael Richter, Guido H E GendollaAbstract:An experiment with 44 participants assessed the moderating effects of four levels of incentive value on cardiovascular responses in active coping. Randomly assigned to one of four different incentive conditions, participants performed a memory Task without knowing its Difficulty in advance. By means of successfully performing the Task participants could either win no reward, 10 Swiss Francs, 20 Swiss Francs, or 30 Swiss Francs. In accordance with the theoretical predictions derived from motivational intensity theory, reactivity of systolic blood pressure and heart rate monotonically increased with incentive value. Thereby, these findings provide additional empirical evidence for the predictions of motivational intensity theory with regard to unclear Task Difficulty and extend recent research (Richter, M., Gendolla, G.H.E., 2006. Incentive effects on cardiovascular reactivity in active coping with unclear Task Difficulty. Int. J. Psychophysiol. 61, 216–225.), which was not conclusive regarding the predicted monotonic relationship between incentive value and cardiovascular reactivity under conditions of unclear Task Difficulty.
-
Incentive effects on cardiovascular reactivity in active coping with unclear Task Difficulty.
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 2005Co-Authors: Michael Richter, Guido H E GendollaAbstract:Abstract Two experiments with a total of 96 participants assessed cardiovascular response in active coping. The studies were run in 2 × 2 designs and manipulated the clarity of Task Difficulty (clear vs. unclear) and incentive value (low vs. high) of a memory Task, which was either easy (Experiment 1) or extremely difficult (Experiment 2). In accordance with the theoretical predictions of motivational intensity theory [Brehm, J.W., Self, E.A., 1989. The intensity of motivation. Annu. Rev. Psychol. 40, 109–131; Wright, R.A., 1996. Brehm's theory of motivation as a model of effort and cardiovascular response. In: Gollwitzer, P.M., Bargh, J.A. (Eds.), The Psychology of Action: Linking Cognition and Motivation to Behaviour, Guilford, New York, pp. 424–453], systolic reactivity varied directly with incentive value when Task Difficulty was unclear. In contrast, when Task Difficulty was clear, incentives had no influence and cardiovascular reactivity was low. These findings provide the first evidence for the predictions of motivational intensity theory with regard to unclear Task Difficulty and complete past research that has focused on the effects of fixed and unfixed Task Difficulty on cardiovascular reactivity.
Jaime Arguello - One of the best experts on this subject based on the ideXlab platform.
-
predicting search Task Difficulty
European Conference on Information Retrieval, 2014Co-Authors: Jaime ArguelloAbstract:Search Task Difficulty refers to a user's assessment about the amount of effort required to complete a search Task. Our goal in this work is to learn predictive models of search Task Difficulty. We evaluate features derived from the user's interaction with the search engine as well as features derived from the user's level of interest in the Task and level of prior knowledge in the Task domain. In addition to user-interaction features used in prior work, we evaluate features generated from scroll and mouse-movement events on the SERP. In some situations, we may prefer a system that can predict search Task Difficulty early in the search session. To this end, we evaluate features in terms of whole-session evidence and first-round evidence, which excludes all interactions starting with the second query. Our results found that the most predictive features were different for whole-session vs.i¾?first-round prediction, that mouseover features were effective for first-round prediction, and that level of interest and prior knowledge features did not improve performance.
-
time pressure user satisfaction and Task Difficulty
ASIST '13 Proceedings of the 76th ASIS&T Annual Meeting: Beyond the Cloud: Rethinking Information Boundaries, 2013Co-Authors: Anita Crescenzi, Robert Capra, Jaime ArguelloAbstract:In this paper, we explore the question of whether or not perceived time pressure and Task Difficulty are predictors of users' satisfaction with their search strategies. We conducted a crowd-sourced user study in which 269 participants completed a total of 600 information-seeking Tasks. Based on self-reported data gathered from post-Task questionnaires, we found that both perceived time pressure and Task Difficulty were significant predictors of satisfaction with search strategy. No interaction effect was found. This exploratory analysis suggests that time pressure can influence search processes and is a dimension that should be investigated in more depth. We propose future research to investigate the impact of time pressure on other contextual factors and search outcome measures.
-
ASIST - Time pressure, user satisfaction and Task Difficulty
Proceedings of the American Society for Information Science and Technology, 2013Co-Authors: Anita Crescenzi, Robert Capra, Jaime ArguelloAbstract:In this paper, we explore the question of whether or not perceived time pressure and Task Difficulty are predictors of users' satisfaction with their search strategies. We conducted a crowd-sourced user study in which 269 participants completed a total of 600 information-seeking Tasks. Based on self-reported data gathered from post-Task questionnaires, we found that both perceived time pressure and Task Difficulty were significant predictors of satisfaction with search strategy. No interaction effect was found. This exploratory analysis suggests that time pressure can influence search processes and is a dimension that should be investigated in more depth. We propose future research to investigate the impact of time pressure on other contextual factors and search outcome measures.
Jingjing Liu - One of the best experts on this subject based on the ideXlab platform.
-
Exploring search Task Difficulty reasons in different Task types and user knowledge groups
Information Processing & Management, 2015Co-Authors: Jingjing Liu, Chang Suk Kim, Caitlin CreelAbstract:Development of a search Task Difficulty reason scheme.Relationship between Task Difficulty and Task type: common and different reasons across Task types.Relationship between Task Difficulty and user knowledge: common and different reasons among different knowledge groups.Implications for general and personalized information retrieval system design. Search Task Difficulty has been attracting much research attention in recent years, mostly regarding its relationship with searchers' behaviors and the prediction of Task Difficulty from search behaviors. However, it remains unknown what makes searchers feel the Difficulty. A study consisting of 48 undergraduate students was conducted to explore this question. Each participant was given 4 search Tasks that were carefully designed following a Task classification scheme. Questionnaires were used to elicit participants' ratings on Task Difficulty and why they gave those ratings. Based on the collected Difficulty reasons, a coding scheme was developed, which covered various aspects of Task, user, and user-Task interaction. Difficulty reasons were then categorized following this scheme. Results showed that searchers reported some common reasons leading to Task Difficulty in different Tasks, but most of the Difficulty reasons varied across Tasks. In addition, Task Difficulty had some common reasons between searchers with low and high levels of topic knowledge, although there were also differences in top Task Difficulty reasons between high and low knowledge users. These findings further our understanding of search Task Difficulty, the relationship between Task Difficulty and Task type, and that between Task Difficulty and knowledge level. The findings can also be helpful with designing Tasks for information search experiments, and have implications on search system design both in general and for personalization based on Task type and searchers' knowledge.
-
User assessment of search Task Difficulty: Relationships between reasons and ratings
Library & Information Science Research, 2015Co-Authors: Jingjing LiuAbstract:Abstract There is an increasing research interest in search Task Difficulty. A recent study developed a user-perceived Task Difficulty reason scheme including 21 reasons (two of which arise prior to searching). Interesting questions arose as to whether the many Difficulty reasons in the scheme were correlated or whether the Difficulty reasons were related to Task Difficulty levels. Using a dataset collected from 48 participants searching on four Tasks, this study examined these questions while also validating the Task Difficulty reason scheme. Results suggest that the 19 Difficulty reasons elicited after a search Task are rarely correlated, and are, instead, independent. Several Difficulty reasons, such as “Task requirements too specific” and “low topic knowledge,” contribute significantly to Difficulty levels. The large discrepancy in the frequency of some reasons' appearance in high, mid, and low Difficulty rating groups may be explained by Task type features. These findings help develop an in-depth explanation of search Task Difficulty and contribute to Task-related information retrieval research and system design.
-
exploring and predicting search Task Difficulty
Conference on Information and Knowledge Management, 2012Co-Authors: Jingjing Liu, Chang Liu, Nicholas J Belkin, Michael J Cole, Xiangmin ZhangAbstract:We report on an investigation of behavioral differences between users in difficult and easy search Tasks. Behavioral factors that can be used in real-time to predict Task Difficulty are identified. User data was collected in a controlled lab experiment (n=38) where each participant completed four search Tasks in the genomics domain. We looked at user behaviors that can be obtained by systems at three levels, distinguished by the time point when the measurements can be done. They are: 1) first-round level at the beginning of the search, 2) accumulated level during the search, and 3) whole-session level by the end of the search. Results show that a number of user behaviors at all three levels differed between easy and difficult Tasks. Models predicting Task Difficulty at all three levels were developed and evaluated. A real-time model incorporating first-round and accumulated levels of behaviors (FA) had fairly good prediction performance (accuracy 83%; precision 88%), which is comparable with the model using the whole-session level behaviors which are not real-time (accuracy 75%; precision 92%). We also found that for efficiency purpose, using only a limited number of significant variables (FC_FA) can obtain a prediction accuracy of 75%, with a precision of 88%. Our findings can help search systems predict Task Difficulty and adapt search results to users.
-
ASIST - Understanding searchers' perception of Task Difficulty: Relationships with Task type
Proceedings of the American Society for Information Science and Technology, 2011Co-Authors: Jingjing Liu, Chang Liu, Xiaojun Yuan, Nicholas J BelkinAbstract:We report findings that help us better understand the Difficulty of Tasks which involve information seeking, retrieving, gathering, and use. We examined the data gathered from two interactive information retrieval user studies on how users' perception of Task Difficulty changes before and after searching for information to solve Tasks, and how the Difficulty of Tasks relates with users' background, previous experience with the Tasks, and knowledge of the Task topics, etc. The two studies employed carefully designed Tasks with different types along several dimensions: Task structure (subTasks being dependent upon or parallel with each other), Task goal in quality (being specific or amorphous), and naming (being named or unnamed). It was found that while in some types of Tasks, users' perceptions of Task Difficulty did not change before and after working on the Tasks, in others, this did, either increasing or decreasing. Specifically, in the dependent-structured Task, this did not change. In the parallel-structured or specific/named Task, it decreased. In the amorphous/unnamed Task, it increased. We also found that users' background factors do not normally correlate with their perceived Task Difficulty, or perceived Difficulty change. In addition to helping understand the dynamic and complex nature of Task Difficulty, our findings have implications for system design that can provide assistance to users with their search and Task solving strategies.
-
predicting Task Difficulty for different Task types
ASIS&T '10 Proceedings of the 73rd ASIS&T Annual Meeting on Navigating Streams in an Information Ecosystem - Volume 47, 2010Co-Authors: Jingjing Liu, Jacek Gwizdka, Chang Liu, Nicholas J BelkinAbstract:This paper reports our investigation of differences in users' behavior between difficult and easy search Tasks, as well as how these differences vary with different types of Tasks. We also report how behavioral predictors of Task Difficulty vary across Task types. In addition, we explored how whole-Task-session level user behaviors and within-Task-session level behaviors differ in Task Difficulty prediction. Data were collected in a controlled lab experiment with 48 participants, each completing 6 search Tasks of three types: single-fact finding, multiple-fact finding and multiple-piece information gathering. Results show that Task type affects the relationships between Task Difficulty and user behaviors and that prediction of Task Difficulty should take account of Task type. Results also show that both whole-session level and within-session level user behaviors can serve as Task Difficulty predictors. Whole-session level variables show higher prediction accuracy, but within-session level factors have the advantage of enabling real-time prediction. These findings can help search systems predict Task Difficulty and adapt to users.
Michael Richter - One of the best experts on this subject based on the ideXlab platform.
-
Task Difficulty effects on cardiac activity
Psychophysiology, 2008Co-Authors: Michael Richter, Antonia Friedrich, Guido H E GendollaAbstract:An experiment with 64 participants manipulated Task Difficulty and assessed cardiac reactivity in active coping over four levels of demand. Participants performed a memory Task while preejection period, heart rate, and blood pressure were assessed. In accordance with the theoretical predictions of R. A. Wright’s (1996) integration of motivational intensity theory (J. W. Brehm & E. A. Self, 1989) with Obrist’s active coping approach (P. A. Obrist, 1981), preejection period and systolic blood pressure reactivity increased with Task Difficulty across the first three Difficulty levels. On the fourth Difficulty levelFwhere success was impossibleFreactivity of both preejection period and systolic blood pressure were low. These findings provide the first clear evidence for the notion of Wright’s integrative model that energy mobilization in active coping is mediated by beta-adrenergic impact on the heart. Descriptors: Task Difficulty, Beta-adrenergic response, Cardiovascular reactivity, Active coping
-
Task Difficulty effects on cardiac activity.
Psychophysiology, 2008Co-Authors: Michael Richter, Antonia Friedrich, Guido H E GendollaAbstract:An experiment with 64 participants manipulated Task Difficulty and assessed cardiac reactivity in active coping over four levels of demand. Participants performed a memory Task while preejection period, heart rate, and blood pressure were assessed. In accordance with the theoretical predictions of R. A. Wright's (1996) integration of motivational intensity theory (J. W. Brehm & E. A. Self, 1989) with Obrist's active coping approach (P. A. Obrist, 1981), preejection period and systolic blood pressure reactivity increased with Task Difficulty across the first three Difficulty levels. On the fourth Difficulty level-where success was impossible-reactivity of both preejection period and systolic blood pressure were low. These findings provide the first clear evidence for the notion of Wright's integrative model that energy mobilization in active coping is mediated by beta-adrenergic impact on the heart.
-
Incentive value, unclear Task Difficulty, and cardiovascular reactivity in active coping.
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 2006Co-Authors: Michael Richter, Guido H E GendollaAbstract:An experiment with 44 participants assessed the moderating effects of four levels of incentive value on cardiovascular responses in active coping. Randomly assigned to one of four different incentive conditions, participants performed a memory Task without knowing its Difficulty in advance. By means of successfully performing the Task participants could either win no reward, 10 Swiss Francs, 20 Swiss Francs, or 30 Swiss Francs. In accordance with the theoretical predictions derived from motivational intensity theory, reactivity of systolic blood pressure and heart rate monotonically increased with incentive value. Thereby, these findings provide additional empirical evidence for the predictions of motivational intensity theory with regard to unclear Task Difficulty and extend recent research (Richter, M., Gendolla, G.H.E., 2006. Incentive effects on cardiovascular reactivity in active coping with unclear Task Difficulty. Int. J. Psychophysiol. 61, 216–225.), which was not conclusive regarding the predicted monotonic relationship between incentive value and cardiovascular reactivity under conditions of unclear Task Difficulty.
-
Incentive effects on cardiovascular reactivity in active coping with unclear Task Difficulty.
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 2005Co-Authors: Michael Richter, Guido H E GendollaAbstract:Abstract Two experiments with a total of 96 participants assessed cardiovascular response in active coping. The studies were run in 2 × 2 designs and manipulated the clarity of Task Difficulty (clear vs. unclear) and incentive value (low vs. high) of a memory Task, which was either easy (Experiment 1) or extremely difficult (Experiment 2). In accordance with the theoretical predictions of motivational intensity theory [Brehm, J.W., Self, E.A., 1989. The intensity of motivation. Annu. Rev. Psychol. 40, 109–131; Wright, R.A., 1996. Brehm's theory of motivation as a model of effort and cardiovascular response. In: Gollwitzer, P.M., Bargh, J.A. (Eds.), The Psychology of Action: Linking Cognition and Motivation to Behaviour, Guilford, New York, pp. 424–453], systolic reactivity varied directly with incentive value when Task Difficulty was unclear. In contrast, when Task Difficulty was clear, incentives had no influence and cardiovascular reactivity was low. These findings provide the first evidence for the predictions of motivational intensity theory with regard to unclear Task Difficulty and complete past research that has focused on the effects of fixed and unfixed Task Difficulty on cardiovascular reactivity.
Michael C. Rush - One of the best experts on this subject based on the ideXlab platform.
-
Achievement Motivation and the Dynamics of Task Difficulty Choices
Journal of Personality and Social Psychology, 1991Co-Authors: L. Allen Slade, Michael C. RushAbstract:Undergraduate students performed a vigilance Task in a study of the dynamic theory of achievement motivation. Positively motivated subjects (n = 66) and negatively motivated subjects (n = 60) did not differ in initial Task Difficulty choices. Both groups shifted to more difficult Tasks over time, but this linear trend interacted with achievement motive group, with positively motivated subjects shifting faster. Quadratic and cubic trends in Task Difficulty choices were also observed. Periodic interruptions attenuated achievement group differences in average Task Difficulty choices. Subject gender affected average Task Difficulty choices, but gender did not interact with theoretically important variables in this study. Achievement motivation has long been associated with Task Difficulty preferences. In an early formulation of achievement motivation theory, Atkinson (1957) proposed that positively motivated subjects (i.e., subjects with motive to achieve success stronger than motive to avoid failure) would prefer Tasks of moderate Difficulty, whereas negatively motivated subjects (i.e., subjects with motive to achieve success weaker than motive to avoid failure) would prefer either very easy or very difficult Tasks. The empirical support for this prediction, however, is weak (cf. Atkinson & Litwin, 1960; Cooper, 1983; Hamilton, 1974). Recently, Kuhl and Blankenship (1979a) presented data that show a more complex pattern of Task Difficulty preferences in that both positively and negatively motivated subjects preferred successively more difficult Tasks over time; that is, there is evidence of a systematic shift toward more difficult Tasks by both motive groups. A theoretical explanation of shifting Task Difficulty choices has been provided in dynamic achievement motivation theory (Atkinson & Birch, 1970,1974). Dynamic achievement theory postulates an interaction of personality (i.e., motive to achieve success and motive to avoid failure) and dynamic motivational forces that affects Task Difficulty choices in an ongoing stream of behavior. Specifically, goal-directed tendencies are thought to possess inertial properties that are similar to mass in Newtonian physics; that is, the tendencies change in importance
