Students' attributional styles regarding academic successes and failures were hypothesized to be moderators of persistence in academic tasks. Attributional style was assessed in 72 fifth graders using the Sydney Attribution Scale (SAS). Persistence was assessed using two behavioral measures and teacher ratings. The behavioral persistence measures involved the number of tasks attempted and time spent working on a difficult reading task and a problem-solving task. The behavioral measures were highly correlated (r = .74) but were unrelated to teacher-rated persistence. Attributional style predicted teacher-rated persistence, R2 = .42, F(12, 59)=3.6, p< ,001, but did not predict any ,of the behavioral persistence measures. Results suggest that students' selfreported attributional styles are related to teacher judgments of persistence. The lack of agreement between teacher ratings and behavioral measures of persistence may have implications for the generalization of research findings relying on either behavioral or teacher-rated persistence measures.Persistence, which is defined here and elsewhere as continued effort when confronted with a difficult or insolvable task (Feather, 1962;Maehr & Braskamp, 1986), is one of the more important behavioral qualities in academic settings. Students frequently struggle with or face temporary confusion in their attempts to master new information or problemsolving strategies. Students who fail to persist in the face of such difficulties may be handicapped in their achievement (Ayres, Cooley, & Dunn, 1990; Torgesen & Licht, 1983). The empirical examination of the persistence construct requires objective measurement. One goal of the current study is to evaluate relationships between behavioral and teacher-rated measures of persistence.In the typical experiment using a behavioral measure of persistence, subjects are given a difficult or impossible task or series of tasks and the experimenter records the number of trials and the time spent on the task before the subject quits (Feather, 1962;Forsterling, 1985;Multon, Brown, & Lent, 1991). Such behavioral measures have good face validity but are rarely supported by any other type of validity data. As researchers have noted, there is little evidence to support the generalizability of these findings to a classroom setting (Andrews & Debus, 1978). The present study compares behavioral persistence measures to teacher ratings of persistence (Ayres et al., 1990). This multimethod approach will allow for comparisons between behavioral measures of persistence and teacher observations. Persistence is seen globally as a behavioral correlate of motivation (Feather, 1962; Maehr & Braskamp, 1986), but in order to design appropriate intervention strategies to improve persistence, knowledge of underlying cognitive and schematic patterns could be valuable.A second goal of this study is to examine one such cognitive variable, attributional style. The seminal research and theorizing of Weiner (1979) and Dweck (1975) applying Requests for reprints should b...

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This study investigated the effect of task difficulty, evaluation condition, and sex of subject on continuing motivation of fifthgraders. Two levels of task difficulty (hard and easy) were crossed with two evaluation conditions (teacher and self). Subjects completed an initial activity and, as a measure of continuing motivation, chose to work on a similar or an alternative activity. An ANOVA of immediate choice revealed significantly higher return rates for teacher evaluation and for boys over girls. No significant treatment effects were noted one week later. Boys returned to a challenging task more than girls did, whereas girls preferred the easier task. Overall, the data contradict the argument that teacher evaluation reduces continuing motivation.

Turbodrills have been used in the oil and gas industry since the 1920s. The general characteristics of a turbodrill are higher power, higher rotary speed (revolutions per minute expressed in RPM) and relatively low torque, due to the high RPM. For applications in which diamond impregnated drill bits are used, hard and abrasive formations for instance, high RPM is desirable. When drilling medium-soft to medium-hard formations, however, using higher torques with lower RPMs can be a more efficient way to drill. Many of the latter applications call for PDC or roller cone drill bits that often produce a higher rate of penetration (ROP) through application of higher weight on bit (WOB). When lower speeds and higher torque are required, turbodrill speeds must be reduced. This is accomplished through use of a gearbox.For decades, attempts have been made to develop gearboxes that run in conjunction with the turbodrill. These developments have had limited success for two primary reasons: failures resulting from axial thrust loading on the gears, and longevity failures resulting from inadequate sealing for lubrication in the gear train. This paper provides insight into current technical developments addressing these two issues. Further discussion defines the applications in which geared turbodrilling will benefit drilling processes. Turbodrill TheoryThe concept of using gearing in conjunction with turbodrills is not new. The inherent design of a turbodrill lends itself to high power, high speed and a corresponding output torque. Turbodrills derive their power from the fluid flow through the power section (also referred to as a turbine section). Flow rates in drilling are, in large part, dictated by the need to overcome frictional losses in the drill string and annulus, while balancing fluid velocities for sufficient evacuation of cutting from the wellbore. Turbodrill needs cannot, in most cases, dictate system flow parameters, so tools are designed to be as efficient as possible over a range of hydraulic parameters. Optimizing turbodrill configurations for an application is accomplished by adding or removing stages to vary power output, and by utilizing turbine blade arrangements that produce desirable characteristics in anticipated hydraulic conditions. Output RPM and torque are inversely proportional in downhole hydraulic motors. Although turbodrills are very powerful tools, the power PETROLEUM SOCIETY

In Educational Comment 1965, edited by Edward B. Wickes and Thomas C. Gibney, College of Education, The University of Toledo (Ohio), appear six articles which give some provocative insight into some fundamental issues of learning theory and mathematics instruction.