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PubMed1993

Characteristics of dean's letters in 1981 and 1992.

PURPOSE: To compare results from 1981 and 1992 national surveys of the writers of medical school dean's letters, and to rate the 1992 letters based on the guidelines recommended by the Association of American Medical Colleges (AAMC). METHOD: In early 1992 a survey was administered to the dean's letter writers at all 125 U.S. medical schools with fully accredited four-year programs; the survey incorporated many items from a 1981 survey. In addition, 550 dean's letters from all U.S. medical schools for the graduating class of 1992 were collected and rated based on guidelines published by the AAMC in 1989. RESULTS: The response rate of the 1992 survey was comparable to that of the 1981 survey (85% and 87%, respectively). In both surveys, slightly more than half the schools used more than one letter writer; however, the 1992 letters were longer and there were more of them, in spite of the fact that there were approximately 700 fewer graduates. In 1992 the estimated total cost per school was $25,000 (comparable data were not collected in 1981). The ratings of the letters revealed that only 38% of the schools introduced their letters as letters of "evaluation," as recommended by the AAMC, and that 15% of the schools failed to use the AAMC guidelines for format. When the schools were rated for overall quality (i.e., format combined with information about the students' performance in comparison with that of peers), 55% of the schools passed and 45% failed. CONCLUSION: Several recommendations for improving dean's letters are discussed, including the following: (1) all dean's letters should be formatted according to the AAMC guidelines; (2) each school should have one person responsible for central overview of the school's letters; and (3) for comparative performance information, schools should at least give the percentages of grades given in the required clerkships, and it would be preferable for them to employ systems that group students into four to six groups and to indicate the percentage of students in each group.

Correspondence as Topic↗
PubMed1992

Neighborhood frequency effects and letter visibility in visual word recognition.

Two experiments are described that measured lexical decision latencies and errors to five-letter French words with a single higher frequency orthographic neighbor and control words with no higher frequency neighbors. The higher frequency neighbor differed from the stimulus word by either the second letter (e.g., ASTRE-AUTRE) or the fourth letter (CHOPE-CHOSE). Neighborhood frequency effects were found to interact with this factor, and significant interference was observed only to CHOPE-type words. The effects of neighborhood frequency were also found to interact with the position of initial fixation in the stimulus word (either the second letter or the fourth letter). Interference was greatly reduced when the initial fixation was on the critical disambiguating letter (i.e., the letter P in CHOPE). Moreover, word recognition was improved when subjects initially fixated the second letter relative to when they initially fixated the fourth letter of a five-letter word, but this second-letter advantage practically disappeared when the stimulus differed from a more frequent word by its fourth letter. The results are interpreted in terms of the interaction between visual and lexical factors in visual work recognition.

Adult↗
PubMed1999

Which way is upright and normal? Haptic perception of letters above head level.

In three experiments, the perception of the apparent orientation of block letters shown in various orientations above the subject's head in the horizontal plane was examined. A block letter F with its front facing down toward the observer has two crossbars on its right side; the top is the part with the long crossbar, and the base has no bar. The experiments involved changing the locations of these parts with respect to the observer. In Experiment 1, the subjects using touch most often identified a letter as having its left and right sides in a normal orientation if the front of the block letter faced upwards away from the observer, with the bar on the right and the top of the letter farther from the subject than the letter's base. In Experiment 2, the subjects judging visual uprightness favored positions in which the bars were on the right, the top of the block letter was near them, and the letter's front faced downwards toward the observer. In Experiment 3, the subjects using touch most often assessed letters as being upright if the top of the letter was the farthest part and the bar was on the right. The results suggest that, when assessing orientation, subjects using touch favored positions that would be reached by a letter moving vertically upwards from table height, but subjects relying on vision favored positions reached by a letter moving in an are centered on the subject's head (on the eyes, in particular).

Adolescent↗
PubMed1991

Automatic letter priming in an alphabetic decision task.

An alphabetic decision task was used to study effects of form priming on letter recognition at very short prime durations (20 to 80 msec). The task required subjects to decide whether a stimulus was a letter or a nonletter. Experiment 1 showed clear facilitatory effects of primes being either physically or nominally identical to the targets, with a stable advantage for the former. Experiment 2 demonstrated that uppercase letters are classified more rapidly as letters (vs. non-letters) when they are preceded by a briefly exposed, forward- and backward-masked, visually similar uppercase letter than when they are preceded by a visually dissimilar uppercase letter. Finally, Experiment 3 demonstrated that nominally identical and visually similar primes facilitate processing more than do nominally identical, visually dissimilar primes. The alphabetic decision task proved to produce sensitive and stable priming effects at the feature, letter, and response-choice level. The present results on letter-letter priming thus constitute a solid data base against which to evaluate other priming effects, such as word-letter priming. The results are discussed in light of current activation models of letter and word recognition and are compared with data simulated by the interactive activation model (McClelland & Rumelhart, 1981).

Arousal↗
PubMed2005

Communicating safety information to physicians: an examination of dear doctor letters.

PURPOSE: Recent research suggests that letters to healthcare providers may not effectively communicate safety-related information. This study examined whether content, organization, and formatting of dear doctor letters (DDLs) influences physicians' responses to the letters. METHODS: Drugs with warning label changes during 2000 and 2001 were identified, and corresponding DDLs were obtained. Letters were coded for content, organization, and formatting. Ten physicians rated letters on presentation, criticalness of the information, and likelihood of changing practice as a result of the letter. Areas of deficiency were identified. The relationships between key characteristics of the letters and physicians' ratings were examined using correlations; reliability of physicians' ratings was estimated using generalizability theory. RESULTS: For 2000 and 2001, 124 drugs were identified as having had changes to the warning section of the label; DDLs were sent in 32 (25.8%) instances. Letters varied in terms of the placement of key information, use of formatting, and length. Physicians' ratings suggested 25% of the letters were deficient in clarity, 28% in readability, 36% in the ratio of relevant information to supporting information, 36% in key information easily discernable, and 28% in overall effectiveness of communication. Letters with formatting highlighting key information were preferred. Letter length and placement of key information were not correlated with physicians' ratings. CONCLUSIONS: Many DDLs do not communicate labeling changes clearly and effectively. If DDLs are used to communicate safety information to physicians, special formatting and explicit wording should be used to emphasize new information.

Correspondence as Topic↗
PubMed2000

Prediction of letter contrast sensitivity using videokeratographic indices.

PURPOSE: To analyze the relationship between corneal topography and letter contrast sensitivity. METHOD: Experiments were conducted on 59 eyes of 51 patients who had best spectacle-corrected visual acuity of 20/20 or better and no ocular pathology except for the corneal shape. Thirty-nine eyes had an abnormal topographic pattern resulting from keratoconus, and the other 20 eyes showed a normal topographic pattern. Videokeratography was performed with the TMS-2 videokeratoscope, and the surface regularity index, surface asymmetry index, and coefficient of variation of power were obtained for each subject. Letter contrast sensitivity was measured with the CSV-1000LV with spectacle correction. The correlation between the number of correct letters and topographic indices was calculated. RESULTS: The abnormal topography group had a significantly greater loss of letter contrast sensitivity (median = 20 letters) than the normal control (median = 23 letters; P =.0001). There were statistically significant correlations between number of correct letters and the coefficient of variation of power (r = -.77; P =. 001), number of correct letters and surface regularity index (r = -. 76, P =.001), and the number of correct letters and surface asymmetry index (r = -.64; P =.001). The linear regression equation between number of correct letters and the coefficient of variation of power was the number of correct letters = -0.05 x the coefficient of variation of power + 23.2. CONCLUSIONS: Our results suggest that subtle visual deteriorations, which are barely detected by contrast sensitivity testing, can be predicted objectively by the corneal topographic indices.

Adult↗
PubMed2003

Scaling of letter size and contrast equalises perception across eccentricities and set sizes.

Double E(2)N(2) scaling, i.e. magnifying size and contrast, allows modelling of the deterioration of face recognition performance with increasing eccentricity (E) and the size (N) of the set from which a target face has to be identified. E(2) and N(2) values represent the eccentricities and set sizes at which stimulus size and contrast must double in order to keep performance unchanged, whilst parameter K represents the multiplicative interaction between E and N. In the current study we investigated whether double E(2)N(2) scaling can model performance deterioration with increasing eccentricity and set size in letter perception too. Contrast sensitivity for letter perception was investigated as a function of letter size at N=1-8 and E=0 degrees -10 degrees. The superimposition of contrast sensitivity functions produced two scaling surfaces, one for letter size and another for contrast, which allowed modelling of the changes in letter perception with increasing E and N. With increasing eccentricity/set size the change of scale was much faster for contrast than letter size. Thus, in letter perception, contrast scaling was more important than spatial scaling. When compared with face perception, the change of spatial scale with increasing eccentricity was slower for letters whereas the change of contrast scale was similar for both. With increasing set size the changes of both spatial and contrast scales are faster for faces. In spatial scaling the interaction between eccentricity and set size was similar for letters and faces whereas in contrast scaling letters showed no interaction. Thus, letter perception was less affected by eccentricity and set size than face perception.

Adult↗
PubMed1981

Visual detection of multi-letter patterns.

This study addressed two basic questions about the detection of multi-letter patterns: (a) How is the detection of a multi-letter pattern related to the detection of its individual components? (b) How is the detection of a sequence of letters influenced by the observer's familiarity with that sequence? In three experiments observers searched for one-, two-, or three letter patterns embedded in a rapid series of multiple six-letter frames. In Experiment 1, unfamiliar two-letter patterns were detected more accurately than their one-letter components. This two-letter advantage reflects the fact that in an array of fixed size, larger target stimuli contain more information and are easier to discriminate from nontarget alternatives. Quantitative analyses indicated that observers combine information not decisions, about the component letters in a pattern. In Experiment 2, with statistical and physical properties equated, a familiar three-letter pattern (i.e., CAT) was detected more accurately than its unfamiliar anagram (i.e., TCA). This word advantage in word (not letter) detection persisted even after extensive practice and was uninfluenced by the lexical character of distractor items. In Experiment 3, words (e.g., FIB), pronounceable non words (e.g., FIF(, and familiar acronyms (e.g., FBI) were detected more readily than unfamiliar items (e.g., IBF). Thus both orthographic knowledge and familiarity with specific sequences can facilitate perceptual processing in "word" detection.

Cognition↗
PubMed1983

Spatial extent of attention to letters and words.

The spatial extent of attention to visually presented letters and words was investigated using a probe technique. The primary task required subjects to categorize (a) five-letter words, or to categorize the middle letter of (b) five-letter words or (c) five-letter nonwords. The probe task required the subjects to respond when the digit 7 appeared in one of the five letter positions. Probe trials were inserted at the onset of letter and word processing in Experiment 1 and 500 msec after letter and word processing in Experiment 2. In both experiments, probe trials produced a V-shaped function of reaction times across probe positions for the letter-categorization task for word and nonword stimulus conditions. In contrast, a relatively flat reaction time function was found for the word-categorization tasks. An analysis of the data based on a quantitative model of attentional spotlight distributions suggests that the spotlight width in the letter tasks is one letter space, and the spotlight width in the word task is typically five spaces.

Attention↗
PubMed2002

Letter encoding in visual word identification: more evidence for a word-integration explanation for parafoveal preview effects in reading.

A letter string presented briefly in the parafovea facilitates naming a foveally presented word provided that the two stimuli are orthographically similar. The facilitation (called priming) is asymmetrical in that to obtain it, both letter strings must have the first letters in common. One possible explanation, a letter-integration hypothesis, proposes that readers only identify the letters at the beginning of the parafoveal stimulus, an action that facilitates processing the target. Another explanation, a word-integration hypothesis, postulates that all the letters of the parafoveal stimulus are identified and that the asymmetry occurs because the first letters of the parafoveal stimulus are weighted more heavily than the later ones. The two accounts differ in the way the position of the first letter is determined: The first postulates that readers know the side to identify first without reference to the stimulus; the second postulates that readers establish an order on the stimuli postcategorically. To distinguish the views, we presented English and Hebrew stimuli to bilingual readers. Readers could not anticipate the position of the first letters; hence, if the letter-integration explanation is correct, the asymmetry in the priming should be attenuated. Consistent with the word-integration explanation, however, priming occurred when the target shared the beginning letters with the prime in both languages.

Adult↗
PubMed2005

German capitalization of nouns and the detection of letters in continuous text.

The missing-letter effect refers to the phenomenon that letters are more difficult to detect in common function words (such as the) than in content words. Assuming that the missing-letter effect is diagnostic of the extraction of text structure, we exploited a special feature of German--the convention to capitalize the initial letter of nouns. Given the great flexibility of word order in German, it was proposed that this convention might help readers specify the structure of the sentence. Therefore orthographic variations that violate the capitalization rules should disrupt structure extraction and should result in a reduced missing-letter effect. The results indicated that: 1) capitalization of function words eliminated the missing-letter effect, but not at the beginning of a sentence; 2) A missing-letter effect occurred when the capitalization of the first letter was correct, but was followed by typecase alternation, and also when the size of the initial letters was relatively large for function words, but relatively small for content words. The results were discussed with respect to the possible contributions of visual familiarity, structural role, and processing time to the missing-letter effect, taking into account that a capitalized initial letter conveys significant information about the word class for German readers. Thus, the present results indicate that readers take advantage not only of function words but of any other information (here the capitalization of nouns) that helps to extract the structure of a sentence.

Analysis of Variance↗
PubMed1982

Letter identification in words and non-words, with variation in visual angle and delay of position cue.

Two experiments are described in which subjects were required to report the name of a single position-cued 'critical' letter in a tachistoscopically displayed string of four letters. The stimulus characters were arranged to form three types of letter strings: (i) strings in which the letters did not form words; (ii) words in which contextual constraint of the critical letters was minimised; and (iii) words in which contextual constraint of the critical letters was maximised. The serial position of the letter to be identified in each string was cued at delays of -500, -100, and +500 ms, in experiment 1 and at delays of -510 and +510 ms in experiment 2, and in both experiments one group of subjects responded to letter strings which subtended a horizontal visual angle of 3.95 deg, while a second group responded to strings which subtended 1.02 deg. Correct identifications of critical letters showed that the presentation of words resulted in superior performance. This 'word superiority effect' is consistent with earlier findings implying that it has a perceptual locus. For the stimuli which subtended the large visual angle the word advantage was detrimentally affected only when the position of the critical letter to be identified was cued either 500 or 510 ms prior to the display of the letter string.

Cues↗
PubMed1994

The relative effectiveness of three reminder letters. On making and keeping mammogram appointments.

One hundred fifty women who had previously had at least one mammogram were sent one of three prompt letters informing them that they were due for screening. The letters were either reassuring, anxiety provoking, or the standard hospital prompt. Based on a review of the literature, we hypothesized that the reassuring letter would be most effective in motivating women to schedule and keep appointments, the anxiety-provoking letter would produce an intermediate level fo compliance, and the standard hospital letter would be least effective. Our hypothesis was partially supported. Overall, 45% of the women in the study scheduled mammogram appointments. This included 54% of those who received the reassuring letter, 42% of those who received the anxiety provoking letter, and 38% of those who received the standard letter. Although the results were in the predicted direction, the results of a chi-square test indicated that differences among groups were not statistically significant. When the dependent measure was number of appointments kept, rather than scheduled, however, significantly more women who received the reassuring letter actually kept their appointments compared with those who received the standard hospital letter. Subsequent analyses suggested that having a family history of breast cancer, receiving a reassuring letter, and being older than 50 years were important factors in scheduling appointments.

Adult↗
PubMed1993

The relative effectiveness of three reminder letters on making and keeping mammogram appointments.

One hundred fifty women who had previously had at least one mammogram were sent one of three prompt letters informing them that they were due for screening. The letters were either reassuring, anxiety provoking, or the standard hospital prompt. Based on a review of the literature, we hypothesized that the reassuring letter would be most effective in motivating women to schedule and keep appointments, the anxiety-provoking letter would produce an intermediate level of compliance, and the standard hospital letter would be least effective. Our hypothesis was partially supported. Overall, 45% of the women in the study scheduled mammogram appointments. This included 54% of those who received the reassuring letter, 42% of those who received the anxiety-provoking letter, and 38% of those who received the standard letter. Although the results were in the predicted direction, the results of a chi-square test indicated that differences among groups were not statistically significant. When the dependent measure was number of appointments kept, rather than scheduled, however, significantly more women who received the reassuring letter actually kept their appointments compared with those who received the standard hospital letter. Subsequent analyses suggested that having a family history of breast cancer, receiving a reassuring letter, and being older than 50 years were important factors in scheduling appointments.

Aged↗
PubMed2001

A follow-up study of the characteristics of dean's letters.

PURPOSE: To assess the content and quality of dean's letters since the publication of guidelines recommended by the Association of American Medical Colleges (AAMC) in 1989. METHOD: In 1998, the dean's letter writers at all 124 U.S. medical schools were surveyed. The questionnaire incorporated items from two previous surveys (1981 and 1992). In addition, samples of dean's letters (n = 451) from all U.S. medical schools for the graduating class of 1998 were rated based on the AAMC's guidelines. RESULTS: The response rate of the 1998 survey (66%) was lower than those of the two previous surveys (87% for 1992 and 85% for 1981). Schools that prepared letters that followed the AAMC's guidelines were somewhat more likely to have responded. According to the letter writers in 1998, close to 300,000 letters (approximately 1,050,000 pages total) were sent to residency directors, at an estimated cost of $26,000 per school. A total of 65% of schools produced adequate dean's letters based on the 1989 AAMC's guidelines, compared with 55% in 1992. Many schools were organizing the dean's letter in more readable formats, and more schools provided information that allowed for a comparison of students within the same school. CONCLUSION: The improvements in dean's letters are encouraging, but ten years after the AAMC's guidelines, 35% of U.S. schools still produce unacceptable letters. With the addition of the electronic submission of information, it is time to review further improvements to the dean's letter.

Academic Medical Centers↗
PubMed1997

Development of motion-defined figure-ground segregation in preschool and older children, using a letter-identification task.

BACKGROUND: Three-month-old infants can discriminate motion-defined (MD) form, but we do not know the age at which this ability reaches adult levels. Previous psychophysical evidence suggests that different neural mechanisms are involved in the processing of luminance-defined (LD) and MD spatial form in adults. This difference may be reflected in the development of LD versus MD form identification in children. METHODS: We measured speed threshold for identifying MD letters, letter-chart (i.e, Snellen) acuity for high-contrast LD letters and single-letter acuity for high- and low-contrast LD letters. Forty-seven children between 3 and 12 years of age and 20 adult subjects were tested. RESULTS: Development to the adult level was observed as follows: low-contrast single-letter acuity before 3 years; high-contrast single-letter acuity by 5 to 6 years; the ability to identify MD letters by 7 to 8 years; letter-chart acuity by 9 to 10 years. CONCLUSIONS: MD form identification continues to mature in preschool children. LD form identification also matures in this age group but with a different time course. MD letters are not equivalent to low-contrast letters developmentally. Our findings provide further support for the hypothesis that the spatial aspects of MD and LD form are processed separately to some extent.

Adult↗
PubMed2001

How crowding affects letter confusion.

BACKGROUND: Acuity for letter recognition is known to be worse when multiple letters are presented with narrow interletter spacings than with wide spacings. How would interletter spacing affect the kind of errors made by human subjects? METHODS: Five-letter strings that were randomly drawn from the 26 uppercase letters of the English alphabet were presented foveally to the subjects. The interletter spacings were 1.0 and 0.1 letter height. Letter confusion matrices were constructed from the data collected using these spacing conditions. RESULTS: Narrow- and wide-spacing letter strings produced different letter confusion matrices. Aside from the letter confusions that were shared by both wide- and narrow-spacing strings, narrow-spacing strings produced more random confusions and a set of unique letter confusions, which was not observed under the wide-spacing condition. CONCLUSION: Increased random guessing and lateral interactions between features of neighboring letters can account for most of the acuity deterioration observed under the narrow-spacing condition.

Adult↗
PubMed1990

Differences in the legibility of letters at contrast threshold using the Pelli-Robson chart.

One disadvantage of using high-contrast letters as test objects when measuring visual acuity is the fact that they are not of equal legibility. A number of charts are now commercially available that assess contrast sensitivity using letter targets. This study attempted to assess the legibility of letters at contrast threshold on the Pelli-Robson letter contrast sensitivity chart by determining the percentage of correct responses for each of the ten Sloan letters at contrast threshold. Results of 493 contrast sensitivity measurements taken in optometric practice indicated that there is a definite difference in legibility between letters at contrast threshold as for letters at acuity threshold. The data suggest that the probability of correctly identifying two out of a group of three letters at threshold on the Pelli-Robson chart varies between 67% and 97% due to letter type alone. Because of the very regular and pronounced miscalling of the letter C as an O, we suggest that this should be accepted as a correct call during threshold measurements on the Pelli-Robson chart. This helps to balance the legibility of different groups of letters.

Contrast Sensitivity↗