On Publishing Extended Abstracts,and Reviews

A suggestion is made that scientific journals should publish only extended abstracts of research papers and full-length review-style papers.     

Helping people to sort it out: The role of social support in the Job Strain Model

This paper reports three studies of occupational stress investigating the role of social support as an intervening variable in the Job Strain Model (Karasek, 1979). A computer simulated mail-sorting work environment was used to assess the effect of demands, control and social support on measures of strain, satisfaction, and perceived and actual task performance. The first experiment ( N =60) tests the basic Job Strain Model by manipulating levels of task demand and control. The second experiment ( N =120) compares high and low levels of two types of social support (informational support and emotional support) to determine whether and how they interact with extreme conditions of the Job Strain Model (high strain and low strain). The final experiment ( N =90) investigates positive and negative forms of social support (praise and criticism) in relation to extreme job strain conditions. Results show that the job strain model is consistent with the stress and performance data, although stress showed no Demand ×Control interaction. Social supports increased arousal, satisfaction and perceived performance, but did not affect stress or task performance. Moreover, contrary to buffer theories, social supports did not interact with the job strain variables. Congruence between preferred and experienced emotional support levels also predicted performance.     

Testing the 3-factor model of occupational stress: the impact of demands, control and social support on a mail sorting task

This study tests a 3-factor model of occupational stress, which predicts that job demands, job control and social support influence levels of strain. In a laboratory simulation of mail sorting, task demands, control and social supports were manipulated systematically. Pre- and post-task measures of self reported stress and arousal were compared across groups. Performance was measured continuously during the computer task and all 120 participants reported their perceived performance afterwards. Stress was found to be higher and perceived performance was lower in conditions of high demand; this pattern was also observed in conditions of low social support. Contrary to the hypotheses put forward in this paper, task control did not affect stress and the manipulations did not interact to produce elevated stress. However, task performance was poorer in conditions of high demand and in conditions of low control, and there was a significant interaction between demand and control for performance. Work preference measures indicated that the level of fit between ideal and actual social support influenced stress and perceived performance.     

Vec and vech operators for matrices,with some uses in jacobians and multivariate statistics

The vec of a matrix X stacks columns of X one under another in a single column; the vech of a square matrix X does the same thing but starting each column at its diagonal element. The Jacobian of a one-to-one transformation X → Y is then ∣∣?(vecX)/?(vecY) ∣∣ when X and Y each have functionally independent elements; it is ∣∣ ?(vechX)/?(vechY) ∣∣ when X and Y are symmetric; and there is a general form for when X and Y are other patterned matrices. Kronecker product properties of vec(ABC) permit easy evaluation of this determinant in many cases. The vec and vech operators are also very convenient in developing results in multivariate statistics.