Armand Smits

This study addresses the question of how established organizations develop new business models over time, using a process research approach to trace how four business model innovation trajectories unfold. With organizational learning as analytical lens, we discern two process patterns: "drifting" starts with an emphasis on experiential learning and shifts later to cognitive search; "leaping," in contrast, starts with an emphasis on cognitive search and shifts later to experiential learning. Both drifting and leaping can result in radical business model innovations, while their occurrence depends on whether a new business model takes off from an existing model and when it goes into operation. We discuss the implications of these findings for theory on business models and organizational learning.

Grol R (Department of Family Medicine, Nijmegen University, St Annastraat 284, Postbus 9101, 6500 HN Nijmegen, The Netherlands), Mokkink H, van Eijk J, Beek M, Mesker P and Mesker-Niesten J. Work satisfaction of general practitioners and the quality of patient care.Family Practice 1985; 2: 128–135. The emotional reactions of 57 general practitioners to three aspects of work was assessed by means of questionnaires. The quality of patient care was assessed by means of observations of general practice consultations, assessment of audiotaped consulting hour contacts and an analysis of the referral and prescription figures. A distinction was made between the degree of positive and the degree of negative feelings general practitioners have about their work. Many positive feelings (satisfaction, feeling at ease) correlated with more openness to patients, more attention to psychosocial aspects of the complaints but also with a higher rate of referral to medical specialists. On the other hand, many negative feelings (frustration, tension, lack of time) correlated with a high prescription rate and with giving little explanation to patients. To some extent the way that work is experienced by general practitioners correlated with the quality of care for the patients, but what constitutes cause and effect requires further study. A reflection of a doctor's own feelings about work should become part of training, continuing education and medical audit programmes.

We present measurements of the transport spin polarization of ${\mathrm{Ni}}_{x}{\mathrm{Fe}}_{1\ensuremath{-}x}$ $(0<~x<~1)$ using the recently developed point-contact Andreev reflection technique, and compare them with our first-principles calculations of the spin polarization for this system. Surprisingly, the measured spin polarization is almost composition independent. The results clearly demonstrate that the sign of the transport spin polarization does not coincide with that of the difference of the densities of states at the Fermi level. Calculations indicate that the independence of the spin polarization of the composition is due to compensation of density of states and Fermi velocity in the s and d bands.