Observer agreement for event sequences: Methods and software for sequence alignment and reliability estimates

When sequences of discrete events, or other units, are independently coded by two coders using a set of mutually exclusive and exhaustive codes, but the onset times for the codes are not preserved, it is often unclear how pairs of protocols should be aligned. Yet such alignment is required before Cohen’s kappa, a common agreement statistic, can be computed. Here we describe a method—based on the Needleman and Wunsch (1970) algorithm originally devised for aligning nucleotide sequences—for optimally aligning such sequences; we also offer the results of a simulation study of the behavior of alignment kappa with a number of variables, including number of codes, varying degrees of observer accuracy, sequence length, code variability, and parameters governing the alignment algorithm. We conclude that (1) under most reasonable circumstances, observer accuracies of 90% or better result in alignment kappas of .60 or better; (2) generally, alignment kappas are not strongly affected by sequence length, the number of codes, or the variability in the codes’ probability; (3) alignment kappas are adversely affected when missed events and false alarms are possible; and (4) cost matrices and priority orders used in the algorithm should favor substitutions (i.e., disagreements) over insertions and deletions (i.e., missed events and false alarms). Two computer programs were developed: Global Sequence Alignment, or GSA, for carrying out the simulation study, and Event Alignment, or ELign, a user-oriented program that computes alignment kappa and provides the optimal alignment given a pair of event sequences.     

Clinical teaching: The joy of teaching

Teaching younger physicians the art of medicine should be an activity that engenders joy, satisfaction, and pride for the teacher. It is important to not that technical knowledge of medicine is complemented by special skills in facilitating reflective learning. Methods for teaching and learning the art of medicine are not easy but can be developed for such an important goal.     

What’s up in mental rotation?

We report two experiments on the influence of head tilt on mental rotation. In Experiment I, subjects decided whether dot patterns were or were not repeated about a line. Their reaction times (RTs) were consistent with the interpretation that they mentally rotated the patterns so that the line was subjectively vertical before making their decisions. When the subjects tilted their heads, the RT functions shifted in the direction of the tilt, indicating that the subjective vertical lay closer to the retinal than to the gravitational vertical. In Experiment II, subjects decided whether singly presented alphanumeric characters in various orientations were standard or backward (mirror-reversed). Again, analysis of their RTs suggested mental rotation to the standard upright, but the function was unaffected by head tilt; in this case, the subjects operated in subjective gravitational rather than retinal coordinates. The choice of retinal or gravitational coordinates may depend on whether the stimuli are interpreted egocentrically or as part of the external world.     

Response set effects in recognition memory

In three experiments, Ss responded to individual digits or letters according to whether or not each was in some prememorized list. There were either two possible responses (yes-no condition) or a single response (yes-only and no-only conditions). With memory sets of one, two, or four digits, RT was a linear function of memory set size. The slope of the function was least under the yes-only condition and greatest under the yes-no condition. Nonspecific practice had little effect on any of the slopes. With memory sets of 4, 8, or 12 letters, the slopes under the yes-only and yes-no conditions did not seem to differ, and practice with specific sets flattened the function considerably in both cases. Overall, the errors under the yes-no condition were mostly false alarms, those under the no-only condition mostly misses, and those under the yes-no condition were divided about equally. The results are interpreted partially in terms of a multiple-observations model of decision time.     

Response–reinforcer contiguity versus response-rate–reinforcer-rate covariance in rats' lever pressing: Support for a multiscale view

The multiscale molar view sees behavior as a flow, like a river, extended in time. Matching theory expresses the way activities compete for time. Relative time taken by any activity depends on relative induction. The present experiment tested matching theory applied to concurrent contingent and noncontingent food. As adjunctive activities that compete with operant activity, we recorded hopper head entries and presses on a lever near the food hopper that had no programmed consequences. Eight naïve rats were first exposed to a variable-time 60 s schedule, which across conditions was gradually transformed into a variable-interval 60 s schedule by increasing the proportion of food that was delivered contingent on pressing a lever far from the hopper. Another group of 4 rats that had been trained to press a lever near a food hopper were introduced in the second condition, in which one food delivery was contingent on far-lever pressing. We found induction following a power function to describe pressing on the far lever (operant activity). Matching theory combined with power-function induction also accounted for adjunctive activity. Results with single contingent food deliveries provided little support for the molecular view that behavior consists of discrete responses “strengthened” by immediately following reinforcers.     

Coping Mechanisms for Psychosomatic Symptoms among Aging Roman Catholic German priests

To identify and investigate coping mechanisms and other factors which may impact upon the psychosomatic symptoms of aging German Roman Catholic priests. A cross-sectional study was conducted among 499 aging German Roman Catholic priests with standardized questionnaires: Brief Symptom Inventory, Coping Inventory Stressful Situations, and Religious Coping Scale. Task-Oriented Coping exhibited a significant difference between the two groups. Multiple regression analyses indicated that psychosomatic symptoms could be best predicted by means of Task-Oriented Coping mechanisms, identification with priesthood, and by a low Negative Religious Coping. The success of adaptive coping processes for older clergy may depend on how they employ strategies, strengthen their spiritual dimensions, and manage important psychosocial aspects of aging. In our sample, Depression and Somatization are explained best by Emotion-Oriented Coping. It is desirable for aging priests to be aware of protective factors like Role Identification, Task-Oriented Coping, and low Negative Religious Coping, which may be helpful in improving their psychological well-being.