Assimilation and contrast effects in performance ratings: Effects of rating the previous performance on rating subsequent performance.

1996 ◽  
Vol 81 (4) ◽  
pp. 436-442 ◽  
Author(s):  
H. Canan Sumer ◽  
Patrick A. Knight
Keyword(s):  
Performance Ratings ◽  
Contrast Effects ◽  
Subsequent Performance

scholarly journals Getting Rid of Performance Ratings: Genius or Folly? A Debate

2016 ◽  
Vol 9 (2) ◽  
pp. 219-252 ◽  
Author(s):  
Seymour Adler ◽  
Michael Campion ◽  
Alan Colquitt ◽  
Amy Grubb ◽  
Kevin Murphy ◽  
...  
Keyword(s):  
Performance Management ◽  
Performance Appraisal ◽  
Performance Feedback ◽  
Performance Ratings ◽  
Management Process ◽  
Management Reform ◽  
Research And Practice ◽  
Subsequent Performance ◽  
Weak Relationship ◽  
Effective Performance

Despite years of research and practice, dissatisfaction with performance appraisal is at an all-time high. Organizations are contemplating changes to their performance management systems, the most controversial of which is whether to eliminate performance ratings. The pros and cons of retaining performance ratings were the subject of a lively, standing-room-only debate at the 2015 Society for Industrial and Organizational Psychology conference in Philadelphia (Adler, 2015). Given the high interest in this topic, this article recaps the points made by the panelists who participated in the debate. The arguments for eliminating ratings include these: (a) the disappointing interventions, (b) the disagreement when multiple raters evaluate the same performance, (c) the failure to develop adequate criteria for evaluating ratings, (d) the weak relationship between the performance of ratees and the ratings they receive, (e) the conflicting purposes of performance ratings in organizations, (f) the inconsistent effects of performance feedback on subsequent performance, and (g) the weak relationship between performance rating research and practice in organizations. The arguments for retaining ratings include (a) the recognition that changing the rating process is likely to have minimal effect on the performance management process as a whole, (b) performance is always evaluated in some manner, (c) “too hard” is no excuse for industrial–organizational (I-O) psychology, (d) ratings and differentiated evaluations have many merits for improving organizations, (e) artificial tradeoffs are driving organizations to inappropriately abandon ratings, (f) the alternatives to ratings may be worse, and (g) the better questions are these: How could performance ratings be improved, and are we conducting the entire performance management process properly? The article closes with questions organizational members have found useful for driving effective performance management reform.

Contrast Effects in Performance Ratings: Another Look Across Time

1989 ◽  
Vol 38 (2) ◽  
pp. 131-143 ◽  
Author(s):  
M. Ronald Buckley ◽  
Peter Villanova ◽  
Philip G. Benson
Keyword(s):  
Performance Ratings ◽  
Contrast Effects

Initial decisions and subsequent performance ratings.

1986 ◽  
Vol 71 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Kevin J. Williams ◽  
Angelo S. DeNisi ◽  
Bruce M. Meglino ◽  
Thomas P. Cafferty
Keyword(s):  
Performance Ratings ◽  
Subsequent Performance

Observation of biological macromolecules using various electron microscopic methods

1978 ◽  
Vol 36 (2) ◽  
pp. 170-171
Author(s):  
Mitsuo Ohtsuki ◽  
Michael Sogard
Keyword(s):  
Electron Microscope ◽  
Phase Contrast ◽  
Image Interpretation ◽  
Density Lipoprotein ◽  
Biological Macromolecules ◽  
Contrast Effects ◽  
Biological Structure ◽  
Electron Microscopic ◽  
Structural Investigations ◽  
Staining Techniques

Structural investigations of biological macromolecules commonly employ CTEM with negative staining techniques. Difficulties in valid image interpretation arise, however, due to problems such as variability in thickness and degree of penetration of the staining agent, noise from the supporting film, and artifacts from defocus phase contrast effects. In order to determine the effects of these variables on biological structure, as seen by the electron microscope, negative stained macromolecules of high density lipoprotein-3 (HDL3) from human serum were analyzed with both CTEM and STEM, and results were then compared with CTEM micrographs of freeze-etched HDL3. In addition, we altered the structure of this molecule by digesting away its phospholipid component with phospholipase A2 and look for consistent changes in structure.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

High-Voltage Scanning Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 6-7
Author(s):  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Wave Optics ◽  
Contrast Effects ◽  
Transmission Electron ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Types Of Information ◽  
Voltage Scanning

The comparison of scanning transmission electron microscopy (STEM) with conventional transmission electron microscopy (CTEM) can best be made by means of the Reciprocity Theorem of wave optics. In Fig. 1 the intensity measured at a point A’ in the CTEM image due to emission from a point B’ in the electron source is equated to the intensity at a point of the detector, B, due to emission from a point A In the source In the STEM. On this basis it can be demonstrated that contrast effects In the two types of instrument will be similar. The reciprocity relationship can be carried further to include the Instrument design and experimental procedures required to obtain particular types of information. For any. mode of operation providing particular information with one type of microscope, the analagous type of operation giving the same information can be postulated for the other type of microscope. Then the choice between the two types of instrument depends on the practical convenience for obtaining the required Information.

Characteristic Geometry and Diffraction Contrast of Dispersed ThO2 Crystals

1969 ◽  
Vol 27 ◽  
pp. 168-169
Author(s):  
R. J. Horylev ◽  
L. E. Murr
Keyword(s):  
Dark Field ◽  
Particle Orientation ◽  
Contrast Effects ◽  
Strain Fields ◽  
Diffraction Contrast ◽  
Dispersed Particles ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Particle Images ◽  
Diffraction Effects

Smith has shown by dark-field electron microscopy of extracted ThO2 particles from TD-nickel (2% ThO2) that they possess single crystal characteristics. It is generally assumed that these particle dispersions are incoherent. However, some diffraction effects associated with the particle images appeared to be similar to coherency strain fields. The present work will demonstrate conclusively that ThO2 dispersed particles in TD-nickel (2% ThO2) and TD-NiCr (2% ThO2, 20% Cr, Ni) are single crystals. Moreover, the diffraction contrast effects are extinction fringes. That is, these effects arise because of the particle orientation with respect to the electron beam and the extinction conditions for various operating reflections The particles are in fact incoherent.

Experiments on REM and SREM using a Tem/Stem Microscope with a Configurable Angle-Resolving Detector

1990 ◽  
Vol 48 (1) ◽  
pp. 338-339
Author(s):  
H. Banzhof ◽  
I. Daberkow
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Crystal Surface ◽  
High Energy ◽  
Contrast Effects ◽  
Atomic Steps ◽  
Single Crystal Surfaces ◽  
Platinum Single Crystal ◽  
Reflection Electron Microscopy ◽  
Beam Reflection

A Philips EM 420 electron microscope equipped with a field emission gun and an external STEM unit was used to compare images of single crystal surfaces taken by conventional reflection electron microscopy (REM) and scanning reflection electron microscopy (SREM). In addition an angle-resolving detector system developed by Daberkow and Herrmann was used to record SREM images with the detector shape adjusted to different details of the convergent beam reflection high energy electron diffraction (CBRHEED) pattern.Platinum single crystal spheres with smooth facets, prepared by melting a thin Pt wire in an oxyhydrogen flame, served as objects. Fig. 1 gives a conventional REM image of a (111)Pt single crystal surface, while Fig. 2 shows a SREM record of the same area. Both images were taken with the (555) reflection near the azimuth. A comparison shows that the contrast effects of atomic steps are similar for both techniques, although the depth of focus of the SREM image is reduced as a result of the large illuminating aperture. But differences are observed at the lengthened images of small depressions and protrusions formed by atomic steps, which give a symmetrical contrast profile in the REM image, while an asymmetric black-white contrast is observed in the SREM micrograph. Furthermore the irregular structures which may be seen in the middle of Fig. 2 are not visible in the REM image, although it was taken after the SREM record.

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