Task exposures in an office environment: a comparison of methods

Task-related factors such as frequency and duration are associated with musculoskeletal disorders in office settings. The primary objective was to compare various task recording methods as measures of exposure in an office workplace. A total of 41 workers from different jobs were recruited from a large urban newspaper (71% female, mean age 41 years SD 9.6). Questionnaire, task diaries, direct observation and video methods were used to record tasks. A common set of task codes was used across methods. Different estimates of task duration, number of tasks and task transitions arose from the different methods. Self-report methods did not consistently result in longer task duration estimates. Methodological issues could explain some of the differences in estimates seen between methods observed. It was concluded that different task recording methods result in different estimates of exposure likely due to different exposure constructs. This work addresses issues of exposure measurement in office environments. It is of relevance to ergonomists/researchers interested in how to best assess the risk of injury among office workers. The paper discusses the trade-offs between precision, accuracy and burden in the collection of computer task-based exposure measures and different underlying constructs captures in each method.     

The effect of idle time thresholds on computer use time estimations by electronic monitoring

This study examined the effect of idle time setting on the estimation of computer use times by electronic activity monitoring and validated its use by comparing it with video record observations. Twenty-four study subjects were recruited and their work with computers was monitored for 1 h. With the estimates by video record observation as references, the best idle time settings for electronic activity monitoring with the least relative errors were 25, 2.5 and 2.5 s, respectively, for total computer, keyboard and mouse use time estimations. These estimates were highly correlated with the corresponding references (r = 0.918–0.964, p < 0.0001), accompanied by limited mean estimate differences ranging from ?3.0 ± 2.8% to 1.3 ± 1.6%. The estimates by self-report were moderately correlated with the corresponding references (r = 0.387–0.678), with greater mean estimate differences. This study concluded that, for electronic activity monitoring methods, the most appropriate thresholds for idle time setting are 25 s, 2.5 s and 2.5 s for total computer, keyboard and mouse use time estimates, respectively. This method may help evaluate physical work-loading with computer works through a large-scale epidemiological study.     

The use of the portable ergonomic observation method (PEO) to monitor the sitting posture of schoolchildren in the classroom

Contrary to common belief, back pain amongst young people is a frequent phenomenon. Epidemiological studies have found high prevalence rates of back pain amongst schoolchildren. The investigation reported here aims to validate children's self-reporting and the observation of sitting postures to establish the intensity, duration and frequency of exposure in the classroom. The sitting postures of 18 children were recorded using three methods, the portable ergonomic observation method (PEO), video analysis and self-report. The three methods were compared. PEO was significantly correlated with video analysis of the sitting postures after development of the method. Self-report was not significantly correlated with video analysis of the sitting postures. Therefore PEO was selected as the main observation tool in further analysis of children's sitting posture in schools in South-East England as part of a large research programme investigating back pain amongst schoolchildren.     

Measuring Mobile Phone Use: Self-Report Versus Log Data

Approximately 40% of mobile phone use studies published in scholarly communication journals base their findings on self-report data about how frequently respondents use their mobile phones. Using a subset of a larger representative sample we examine the validity of this type of self-report data by comparing it to server log data. The self-report data correlate only moderately with the server log data, indicating low criterion validity. The categorical self-report measure asking respondents to estimate “how often” they use their mobile phones fared better than the continuous self-report measure asking them to estimate their mobile phone activity “yesterday.” A multivariate exploratory analysis further suggests that it may be difficult to identify under- and overreporting using demographic variables alone.     

Computer anxiety and anger: the impact of computer use, computer experience, and self-efficacy beliefs

Past research has demonstrated that the level of computer experience users have is the most valuable predictor in whether or not they will suffer computer anxiety symptoms, but this was not the case in the present study. No research was found which examined the correlates of computer anger symptoms. In the current study, the relationship between the computer use (frequency and duration), computer experience, and self-efficacy beliefs of users were analyzed as predictors for computer anxiety and anger symptoms. Questionnaire data from a sample of 242 university students were analyzed. The results indicated that computer self-efficacy beliefs, not computer experience or use, had the largest significant relationship with both computer anxiety, and anger. It is suggested that self-efficacy beliefs be increased so that users may experience lower levels of anxiety and anger. These findings are contrary to the trend of training computer users in specific computer domains. As computer anxiety and anger are negative psychological “states”, an immediate method to deal with these negative emotions should be developed. One possibility that is explored is the application of computer-based therapy that can be used while a user is experiencing negative emotional symptoms.     

Quantifying engagement: Measuring player involvement in human–avatar interactions

This research investigated the merits of using an established system for rating behavioral cues of involvement in human dyadic interactions (i.e., face-to-face conversation) to measure involvement in human–avatar interactions. Gameplay audio–video and self-report data from a Feasibility Trial and Free Choice study of an effective peer resistance skill building simulation game (DRAMA–RAMA™) were used to evaluate reliability and validity of the rating system when applied to human–avatar interactions. The Free Choice study used a revised game prototype that was altered to be more engaging. Both studies involved girls enrolled in a public middle school in Central Florida that served a predominately Hispanic (greater than 80%), low-income student population. Audio–video data were coded by two raters, trained in the rating system. Self-report data were generated using measures of perceived realism, predictability and flow administered immediately after game play. Hypotheses for reliability and validity were supported: reliability values mirrored those found in the human dyadic interaction literature. Validity was supported by factor analysis, significantly higher levels of involvement in Free Choice as compared to Feasibility Trial players, and correlations between involvement dimension sub scores and self-report measures. Results have implications for the science of both skill-training intervention research and game design.     

Comparing actual and self-reported measures of Facebook use

Numerous studies exist examining how college students use Facebook and how this affects aspects of their college experience; however, all of these studies have relied on self-report measures of Facebook use. Research in other areas of human behavior has shown that self-report measures are substantially inaccurate when compared to actual behaviors. This study provides the first test of the criterion validity of measures of Facebook frequency by comparing self-reported time spent on the site and number of logins against actual usage as measured by computer monitoring software. A sample of 45 college students installed software that monitored their computer usage for 1 month. There was a strong positive correlation between self-reported and actual time spent on Facebook; however, there was a significant discrepancy between the two. Students spent an average of 26 min (SD = 30) per day on Facebook, significantly lower than the average of 145 (SD = 111) minutes per day obtained through self-report. There was a moderate relationship between number of logins and actual time spent on Facebook. Although there are some limitations of monitoring computer usage, researchers are encouraged to attempt to relate their self-report measures to actual behaviors in order to improve external validity.     

Correlates of computer misuse: data from a self-reporting sample

Most of what is currently known about the causes and social distribution of computer crime is derived from the records of law enforcement agencies or from surveys of organizations that are victims of such crime. Through the use of an alternative data collection strategy, the self-report survey, the present study investigates computer misuse in a sample of Canadian undergraduate university students. The methodology allows an examination of some of the social and perceptual factors that previous research suggests might be related to computer offending. The study reveals that scores on a measure of computer misuse are not strongly correlated with respondents' social characteristics. However, the data also indicate that respondents' beliefs about the ethics and prevalence of misuse affect their own levels of involvement in such activity. The paper concludes with a discussion of some of the implications that these findings might have for the study and for the prevention of computer crime.     

The impact of computer-mediated communication on self-awareness

The present research investigated whether computer-mediated communication enhances users' private self-awareness, while lowering their public self-awareness. Self-report measures of acute private and public self-awareness were administered to 55 subjects following either face-to-face or computer-mediated discussions of two choice-dilemma problems. It was found that, relative to the face-to-face comparison group, subjects using computer-mediation reported significantly higher levels of acute private self-awareness, and marginally lower levels of public self-awareness. Although computer users did not evaluate the social context differently from subjects communicating face-to-face, their evaluations were associated with the degree of acute public self-awareness they were experiencing. Low public self-aware computer users were more likely to evaluate the social context negatively. The social evaluations of face-to-face subjects were not related to their levels of self-awareness. The implications of these findings for future research examining the social psychological impact of computers and their use in different contexts are discussed.     

Computerized scheduled gradual reduction for smokeless tobacco cessation: development and preliminary evaluation of a self-help program

This paper chronicles the development and feasibility testing of a computerized scheduled gradual reduction program for smokeless tobacco cessation. During Study 1, the LifeSign smoking cessation computer was adapted for use with smokeless tobacco by pairing it with an electronic timer. The computer recorded frequency of dips during a baseline phase and prompted for tobacco use during a gradual reduction phase. The timer was used to track the length of dips during baseline and to hold them to a fixed length during the reduction phase. Abstinence rates among 60 male daily smokeless tobacco users who received the program were 29% at 3-month follow-up (biochemically validated) and 19% at 12-month follow-up. Self-reported changes in topography of tobacco use were consistent with the scheduled reduction protocol. Study 2 evaluated a prototype computer that tracked both frequency and duration of dips during baseline and gradually reduced both parameters during the reduction phase. Among 19 subjects who received the program, self-reported abstinence rates were 56% at end of treatment and 11% at 12-month follow-up. Results of these two studies demonstrate the feasibility of computerized scheduled gradual reduction for smokeless tobacco cessation and provide a basis for further product development.     

Nonlinear technology: Changing the conception of extrinsic motivation?

Think-aloud and self-report data from 84 undergraduates were used to examine the relationship between intrinsic motivation, extrinsic motivation, and use of self-regulated learning (SRL) processes. Participants individually learned about the circulatory system with a hypermedia environment for 30 min. During this experimental session, three measures were used to examine the research questions guiding the study. Participants completed a self-report questionnaire that measured their extrinsic and intrinsic motivation. They also completed a pretest and posttest, which assessed learning outcomes. Lastly, think-aloud data were collected to determine the frequency in which participants used SRL process related to planning, monitoring, and strategy use. Results indicate that participants who had high extrinsic and high intrinsic motivation used significantly more planning and monitoring processes when compared to participants who had lower motivation scores for either the extrinsic or intrinsic category. Additionally, participants who had high extrinsic and high intrinsic motivation significantly outperformed those who had low extrinsic and low intrinsic motivation.     

Computer phobia and computer self-efficacy: their association with undergraduates’ use of university computer facilities

Extensive development in universities’ provision of computer facilities may have negative consequences for students prone to computer avoidance. In the present study, undergraduates (N = 363) completed self-report measures on computer phobia and self-efficacy. Results demonstrate that many students follow previous trends by continuing to report levels of computer phobia within the higher parameters of self-report measures. Students who reported either high computer phobia or low computer self-efficacy were less likely to maximise their use of university computer facilities. Moreover, a range of background measures – initial computer experience, regular home use, successful completion of a computer course and introductory tutor’s characteristics – all impacted statistically on self-report responses. Results are discussed with reference to the increasing responsibility placed on students to acquire ICT skills.     

Interactive effects from self-reported physical and psychosocial factors in the workplace on neck pain and disability in female office workers

This study explored the interaction between physical and psychosocial factors in the workplace on neck pain and disability in female computer users. A self-report survey was used to collect data on physical risk factors (monitor location, duration of time spent using the keyboard and mouse) and psychosocial domains (as assessed by the Job Content Questionnaire). The neck disability index was the outcome measure. Interactions among the physical and psychosocial factors were examined in analysis of covariance. High supervisor support, decision authority and skill discretion protect against the negative impact of (1) time spent on computer-based tasks, (2) non-optimal placement of the computer monitor and (3) long duration of mouse use. Office workers with greater neck pain experience a combination of high physical and low psychosocial stressors at work. Prevention and intervention strategies that target both sets of risk factors are likely to be more successful than single intervention programmes.

Statement of Relevance: The results of this study demonstrate that the interaction of physical and psychosocial factors in the workplace has a stronger association with neck pain and disability than the presence of either factor alone. This finding has important implications for strategies aimed at the prevention of musculoskeletal problems in office workers.     

On the interaction of man and EDP use as work activity

The working process in electronic data processing (EDP use) is regarded as a work activity performed by the computer user, and is discussed on the basis of user investigations carried out in a bioscientific research unit. The interaction between man as the EDP user and EDP use takes effect through the EDP task and its requirements of the computer. This relationship leads to justification of the “user system” as a model concept, which offers a better approach to planning and analysis of computer applications integrating the user. A method of judging computer applications as EDP use from the standpoint of the user is presented and explained using the results of investigations using an interactive methods base.     

Customer state estimation with Poisson distribution model

In this paper, a new access log analysis is proposed which estimates both active states and inactive states from observations simultaneously. I improved burst analysis and developed enthusiasm analysis to detect not only active states but also inactive states. Speaking concretely, I constructed a generative model that assumed observations, which meant event occurrence frequency in this paper, were generated under some Poisson distributions. The generative model based on Poisson distributions consists of some distributions including \(\lambda\)s which are less than average frequency and more than average frequency. A cost function, which consists of log likelihood and state transition cost, is defined and enthusiasm levels are estimated from the observations minimizing the cost function. The proposed method was applied to query occurrence data in access logs and I confirmed the proposed method could find active states and inactive states from submission patterns and the results showed relationship between enthusiasm levels and real events.     

Computer work duration and its dependence on the used pause definition

Several ergonomic studies have estimated computer work duration using registration software. In these studies, an arbitrary pause definition (Pd; the minimal time between two computer events to constitute a pause) is chosen and the resulting duration of computer work is estimated. In order to uncover the relationship between the used pause definition and the computer work duration (PWT), we used registration software to record usage patterns of 571 computer users across almost 60,000 working days. For a large range of Pds (1-120 s), we found a shallow, log-linear relationship between PWT and Pds. For keyboard and mouse use, a second-order function fitted the data best. We found that these relationships were dependent on the amount of computer work and subject characteristics. Comparison of exposure duration from studies using different pause definitions should take this into account, since it could lead to misclassification. Software manufacturers and ergonomists assessing computer work duration could use the found relationships for software design and study comparison.     

Computer usage questionnaire: Structure, correlates, and gender differences

Computer usage, computer experience, computer familiarity, and computer anxiety are often discussed as constructs potentially compromising computer-based ability assessment. After presenting and discussing these constructs and associated measures we introduce a brief new questionnaire assessing computer usage. The self-report measure consists of 18 questions asking for the frequency of different computer activities and software usage. Participants were N = 976 high school students who completed the questionnaire and several covariates. Based on theoretical considerations and data driven adjustments a model with a general computer usage factor and three nested content factors (Office, Internet, and Games) is established for a subsample (n = 379) and cross-validated with the remaining sample (n = 597). Weak measurement invariance across gender groups could be established using multi-group confirmatory factor analysis. Differential relations between the questionnaire factors and self-report scales of computer usage, self-concept, and evaluation are reported separately for females and males. It is concluded that computer usage is distinct from other behavior oriented measurement approaches and that it shows a diverging, gender-specific pattern of relations with fluid and crystallized intelligence.     

Design and Analysis of Techniques for Detection of Malicious Activities in Database Systems

Existing host-based Intrusion Detection Systems use the operating system log or the application log to detect misuse or anomaly activities. These methods are not sufficient for detecting intrusion in the database systems. In this paper, we describe a method for detecting malicious activities in a database management system by using data dependency relationships. Typically, before a data item is updated in the database, some other data items are read or written. And after the update, other data items may also be written. These data items read or written in the course of update of a data item construct the read set, prewrite set, and the postwrite set for this data item. The proposed method identifies malicious transactions by comparing these sets with data items read or written in user transactions. We have provided mechanisms for finding data dependency relationships among transactions and use Petri-Nets to model normal data update patterns at user task level. Using this method, we ascertain more hidden anomalies in the database log. Our simulation on synthetic data reveals that the proposed model can achieve desirable performance when both transaction and user task level intrusion detection methods are employed.Yi Hu is a PhD candidate in Computer Science and Computer Engineering Department at the University of Arkansas. His research interests are in Database Intrusion Detection, Database Damage Assessment, Data Mining, and Trust Management. Previously, he received the BS and MS degree in Computer Science from the Southwest Jiaotong University and the University of Arkansas, respectively.Brajendra Panda received his MS degree in mathematics from Utkal University, India, in 1985 and PhD degree in computer science from North Dakota State University in 1994. He is currently an associate professor with the Computer Science and Computer Engineering Department at the University of Arkansas. His research interests include database systems, computer security, digital forensics, and information assurance. He has published over 60 research papers in these areas.     

Sello,a fortran IV program for the transformation of skewed distributions to normality

Many statistical and mathematical procedures are based on the assumption that the variables are normally distributed. Therefore an algorithm and FORTRAN IV computer program SELLO for obtaining univariate nonskewed distributed data from skewed raw data is presented. As an example of the practical use of the program, chemical data from 566 rock specimens collected during 1972 in Sweden were examined. The histograms for no transformation, log and SELLO transformed data are displayed and the changes for pairs of factors from log and SELLO transformed variables obtained with R-mode factor analysis are compared.