bluuebunny/crossref_metadata_2025 huggingface dataset:
Tyrosine protein kinases and spermatogenesis: truncation matters
Authors: Kierszenbaum Abraham L.
Published: January 2006

Protein phosphorylation on serine/threonine or tyrosine residues represents a significant regulatory mechanism in signal transduction during spermatogenesis, oogenesis, and fertilization. There are several families of tyrosine protein kinases operating during spermatogenesis: the Src family of tyrosine protein kinases; the Fujinami poultry sarcoma/feline sarcoma (Fps/Fes) and Fes‐related protein (Fer) subfamily of non‐receptor proteins; and c‐kit, the transmembrane tyrosine kinase receptor that belongs to the family of the PDGF receptor. A remarkable characteristic is the coexistence of full‐length and truncated tyrosine kinases in testis. Most of the truncated forms are present during spermiogenesis. Examples include the truncated forms of Src tyrosine kinase hematopoietic cell kinase (Hck), FerT, and tr‐kit. A feature of FerT and tr‐kit is the kinase domain that ensures the functional properties of the truncated protein. FerT, a regulator of actin assembly/disassembly mediated by cortactin phosphorylation, is present in the acroplaxome, a cytoskeletal plate containing an F‐actin network and linking the acrosome to the spermatid nuclear envelope. This finding suggests that Fer kinase represents one of the tyrosine protein kinases that may contribute to spermatid head shaping. The c‐kit ligand, stem cell factor (SCF), which induces c‐kit dimerization and autophosphorylation, exists as both membrane‐associated and soluble. Although tyrosine protein kinases are prominent in spermatogenesis, a remarkable observation is the paucity of phenotypic alterations in spermatogenic cells in male mice targeted with Fer kinase‐inactivating mutation. It is possible that the redundant functions of the tyrosine protein kinase pool present during spermatogenesis may explain the limited phenotypes of single mutant mice. The production of compound and viable mutant mice, lacking the expression of two or more tyrosine kinases, may shed light on this intriguing issue. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Evaluating a school skills programme for Australian Indigenous children: a pilot study
Authors: McGarrigle Jessica , Nelson Alison
Published: January 2006

The purpose of this study was to evaluate the effectiveness of an occupational therapy skill development programme in improving handwriting, scissor use, visual motor co‐ordination and classroom behaviour, in a group of grade‐one Australian urban Indigenous students. The sample (N = 13) was randomly assigned to an experimental group or comparison group. Both groups were exposed to the intervention. The experimental group received a six week school skills programme in addition to regular schooling, while the comparison group received regular schooling only. Following this, the comparison group received the same six week programme. Participants underwent pre‐ and post‐testing using Beery‐Buktenica's Developmental Test of Visual Motor Integration, Conner's Abbreviated Symptom Questionnaire, and two non‐standardized handwriting and scissor skill measures. Results indicated that participants significantly improved in aspects of handwriting, scissor skills, and behaviour, but not visual motor co‐ordination, following participation in the programme. The experimental group demonstrated greater improvements only in handwriting ability scores (p = 0.037), compared to a comparison group. It was concluded that a school‐based occupational therapy programme was effective in improving handwriting, in a group of grade‐one Australian Indigenous children. Copyright © 2006 John Wiley & Sons, Ltd
Alpha tocopherol supplementation elevates plasma apolipoprotein A1 isoforms in normal healthy subjects
Authors: Aldred Sarah , Sozzi Tommaso , Mudway Ian , Grant Melissa M. , Neubert Hendrik , Kelly Frank J. , Griffiths Helen R.
Published: January 2006

Plasma α‐tocopherol (AT) concentrations are inversely related to cardiovascular (CV) risk; however, intervention studies with AT have failed to show any consistent benefit against CV disease (CVD). Proteomics offers the opportunity to examine novel effects of AT supplementation on protein expression and therefore improve our understanding of the physiological roles of AT. Thus, to investigate the effects of AT supplementation on the plasma proteome of healthy subjects we have undertaken a double‐blind, randomised, parallel design supplementation study in which healthy subjects (n = 32; 11 male and 21 female) consumed AT supplements (134 or 268 mg/day) or placebo capsules for up to 28 days. Plasma samples were obtained before supplementation and after 14 and 28 days of supplementation for analysis of changes in the plasma proteome using 2‐DE and MALDI‐MS. Using semiquantitative proteomics, we observed that proapolipoprotein A1 (identified by MS and Western blotting) was altered at least two‐fold. Using quantitative ELISA techniques, we confirmed a significant increase in plasma apolipoprotein A1 concentration following supplementation with AT which was both time and dose dependent (p < 0.01 after 28 days supplementation with 268 mg AT/day). These data demonstrate the time and dose sensitivity of the plasma proteome to AT supplementation.
Changes in cod muscle proteins during frozen storage revealed by proteome analysis and multivariate data analysis
Authors: Kjærsgård Inger V. H. , Nørrelykke Mette R. , Jessen Flemming
Published: January 2006

Multivariate data analysis has been combined with proteomics to enhance the recovery of information from 2‐DE of cod muscle proteins during different storage conditions. Proteins were extracted according to 11 different storage conditions and samples were resolved by 2‐DE. Data generated by 2‐DE was subjected to principal component analysis (PCA) and discriminant partial least squares regression (DPLSR). Applying PCA to 2‐DE data revealed the samples to form groups according to frozen storage time, whereas differences due to different storage temperatures or chilled storage in modified atmosphere packing did not lead to distinct changes in protein pattern. Applying DPLSR to the 2‐DE data enabled the selection of protein spots critical for differentiation between 3 and 6 months frozen storage with 12 months frozen storage. Some of these protein spots have been identified by MS/MS, revealing myosin light chain 1, 2 and 3, triose‐phosphate isomerase, glyceraldehyde‐3‐phosphate dehydrogenase, aldolase A and two α‐actin fragments, and a nuclease diphosphate kinase B fragment to change in concentration, during frozen storage. Application of proteomics, multivariate data analysis and MS/MS to analyse protein changes in cod muscle proteins during storage has revealed new knowledge on the issue and enables a better understanding of biochemical processes occurring.
Proteomic analysis of growth phase‐dependent proteins of Streptococcus pneumoniae
Authors: Lee Kwang‐Jun , Bae Song‐Mee , Lee Myoung‐Ro , Yeon Sun‐Mi , Lee Young‐Hee , Kim Ki‐Sang
Published: January 2006

Streptococcus pneumoniae is an important human pathogen that causes a variety of diseases, such as pneumonia, bacteremia, meningitis, otitis media, and sinusitis, in both adults and children. The global pattern of growth phase‐dependent protein expression of S. pneumoniae during in vitro culture was analyzed using 2‐DE combined with MALDI‐TOF MS and LC/ESI‐MS/MS. Several protein production patterns were observed at four time points throughout the growth stage, although some protein levels did not change significantly. We focused on the switch in protein expression at the transition from log growth phase to stationary phase. Proteins that were significantly induced or repressed at this point are likely to be involved in central intermediary metabolism, amino acid synthesis, nucleotide, and fatty acid metabolism, cell wall synthesis, protein degradation, and stress responses. This global expression profiling approach has revealed previously unrecognized relationships between proteins in the life of this pathogen.
Population proteomics: An emerging discipline to study metapopulation ecology
Authors: Biron David G. , Loxdale Hugh D. , Ponton Fleur , Moura Hercules , Marché Laurent , Brugidou Christophe , Thomas Frédéric
Published: January 2006

Proteomics research has developed until recently in a relative isolation from other fast‐moving disciplines such as ecology and evolution. This is unfortunate since applying proteomics to these disciplines has apparently the potential to open new perspectives. The huge majority of species indeed exhibit over their entire geographic range a metapopulation structure, occupying habitats that are fragmented and heterogeneous in space and/or through time. Traditionally, population genetics is the main tool used to studying metatopulations, as it describes the spatial structure of populations and the level of gene flow between them. In this Viewpoint, we present the reasons why we think that proteomics, because of the level of integration it promotes, has the potential to resolve interesting issues specific to metapopulation biology and adaptive processes.
Analysis of interaction modes in calix[4]arene–levofloxacin complexes by quantum methods
Authors: Lambert Alexandrine , Regnouf‐de‐Vains Jean‐Bernard , Rinaldi Daniel , Ruiz‐Lopez Manuel F.
Published: January 2006

Host–guest interactions between chiral calix[4]arenes and the antibiotic levofloxacin are analyzed on the basis of quantum mechanical calculations at the density functional (for model systems) and semi‐empirical levels. The calix[4]arene macrocycle carries two (+)‐isomenthyl groups attached to opposing phenyl groups at the lower rim and different substituents (R = H, CH3, tBu, CH2CHCH2, COCH3 and NO2) are considered at the upper rim. Nitro derivatives are expected to form ionized complexes whereas the other derivatives should form neutral complexes with a very low stability. Copyright © 2006 John Wiley & Sons, Ltd.
Orexin‐A is composed of a highly conserved C‐terminal and a specific, hydrophilic N‐terminal region, revealing the structural basis of specific recognition by the orexin‐1 receptor
Authors: Takai Tomoyo , Takaya Takao , Nakano Mutsuko , Akutsu Hideo , Nakagawa Atsushi , Aimoto Saburo , Nagai Katsuya , Ikegami Takahisa
Published: January 2006

Orexins‐A and B, also called hypocretins‐1 and 2, respectively, are neuropeptides that regulate feeding and sleep‐wakefulness by binding to two orphan G protein‐coupled receptors named orexin‐1 (OX1R) and orexin‐2 (OX2R). The sequences and functions of orexins‐A and B are similar to each other, but the high sequence homology (68%) is limited in their C‐terminal half regions (residues 15–33). The sequence of the N‐terminal half region of orexin‐A (residues 1–14), containing two disulfide bonds, is very different from that of orexin‐B. The structure of orexin‐A was determined using two‐dimensional homonuclear and 15N and 13C natural abundance heteronuclear NMR experiments. Orexin‐A had a compact conformation in the N‐terminal half region, which contained a short helix (III:Cys6‐Gln9) and was fixed by the two disulfide bonds, and a helix‐turn‐helix conformation (I:Leu16‐Ala23 and II:Asn25‐Thr32) in the remaining C‐terminal half region. The C‐terminal half region had both hydrophobic and hydrophilic residues, which existed on separate surfaces to provide an amphipathic character in helices I and II. The nine residues on the hydrophobic surface are also well conserved in orexin‐B, and it was reported that the substitution of each of them with alanine resulted in a significant drop in the functional potency at the receptors. Therefore, we suggest that they form the surface responsible for the main hydrophobic interaction with the receptors. On the other hand, the residues on the hydrophilic surface, together with the hydrophilic residues in the N‐terminal half region that form a cluster, are known to make only small contributions to the binding to the receptors through similar alanine‐scan experiments. However, since our structure of orexin‐A showed that large conformational and electrostatical differences between orexins‐A and B were rather concentrated in the N‐terminal half regions, we suggest that the region of orexin‐A is important for the preference for orexin‐A of OX1R. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
QSTR with Extended Topochemical Atom Indices. 7. QSAR of Substituted Benzenes toSaccharomyces cerevisiae
Authors: Roy Kunal , Sanyal Indrani
Published: January 2006

The experimental determination of toxicological properties of commercial chemicals being costly and time consuming process, there is the need to develop mathematical predictive tools to theoretically quantify such properties. In this background, we have modeled the nonspecific toxicity of 51 substituted benzenes to the yeastSaccharomyces cerevisiaeusing extended topochemical atom (ETA) indices. Principal component factor analysis (FA) was used as the data‐preprocessing step to reduce the dimensionality of the data matrix and identify the important variables that are devoid of collinearities. Multiple linear regression (MLR) analyses show that the best ETA model has the following statistical quality:n= 51,Q2= 0.851,Ra2= 0.874,R= 0.940,F= 87.9 (df4, 46),s= 0.235,PRESS= 3.3. We have also modeled the toxicity data using other topological descriptors including Wiener, HosoyaZ, molecular connectivity, kappa shape, BalabanJand E‐state parameters apart from physicochemical parameters like AlogP98, MolRef, H_bond_acceptor and H_bond _donor. The best model shows the following quality:n= 51,Q2=0.837,Ra2 = 0.855,R= 0.929 ,F= 98.9 (df3,47),s= 0.253,PRESS=3.6. An attempt to use a combined set including both ETA and non‐ETA parameters comes out with the following results:n=51,Q2=0.824,Ra2=0.852,R= 0.940,F= 73.0 (df4,46),s= 0.255,PRESS=3.9. Besides FA‐MLR, stepwise regression analysis and partial least squares (PLS) analysis were used as additional statistical tools. The use of the ETA indices suggested negative contributions of functionalities of amino and carboxylic acid substituents on the benzene ring and the presence of the electronegative atoms and positive contributions of branching and functionality of chloro substituent. Using factor scores as independent variables, principal component regression analysis (PCRA) was performed and the derived relations were of the following statistical qualities:Q2values being 0.926, 0.878 and 0.869 whileR2values being 0.942, 0.903 and 0.899 for factor scores derived from ETA, non‐ETA and combined matrices respectively. Thus, it appears that the ETA descriptors have significant potential in QSAR/QSPR/QSTR, which warrants extensive evaluation.
Multiple Rectilinear Prediction and the Resolution into Components
Authors: Guttman Louis
Published: January 2006

It is assumed that a battery of n tests has been resolved into components in a common factor space of r dimensions and a unique factor space of at most n dimensions, where r is much less than n. Simplified formulas for ordinary multiple and partial correlation of tests are derived directly in terms of the components. The best (in the sense of least squares) linear regression equations for predicting factor scores from test scores are derived also in terms of the components. Spearman's “single factor” prediction formulas emerge as special cases. The last part of the paper shows how the communality is an upper bound for multiple correlation. A necessary and sufficient condition is established for the square of the multiple correlation coefficient of test j on the remaining n−1 tests to approach the communality of test j as a limit asn increases indefinitely while r remains constant. Limits are established for partial correlation and regression coefficients and for the prediction of factor scores.
A Modification of the Method of Successive Intervals
Authors: Mosier Charles I.
Published: January 2006

A modification of the method of successive intervals is presented which yields scale values correlating .995 with those from Thurstone's method described by Saffir. Values yielded by the present method can be obtained in 25 per cent of the time required by the older method and are shown to be, on a priori grounds, more reliable as well.
An Approximation Method for Obtaining a Maximized Multiple Criterion
Authors: Wherry Robert J.
Published: January 2006

A new approximation method for obtaining a maximized multiple criterion, based on the formula of Edgerton and Kolbe (2), is presented. By applications to examples from the literature (1, 2), the new method is evaluated in comparison with the Horst approximation (1), a suggested revision of the Horst procedure, and the more exact but more laborious iterative method for the principal axis solution of Hotelling.
A Re-Analysis of a Test of the Theory of Two Factors
Authors: Blakey Robert
Published: January 2006

The study of William Brown and William Stephenson, “A Test of the Theory of Two Factors,” is re-analyzed by means of the Thurstone multiple factor methods. No tests or correlations are left out of the original table of correlations as is done in the original analysis in an attempt to validate the two-factor theory. Space, verbal, and perceptual speed factors similar to those found by Thurstone, Wright, and Garrett are identified. A common factor of “Maturation” is postulated to account for the remaining communality of the tests. A fifth factor is considered to have no significance due to the small amount of variance which it contributes to the total.
A Method of Factor Analysis by Means of which all Coordinates of the Factor Matrix are given Simultaneously
Authors: Horst Paul
Published: January 2006

In general, the methods of factor analysis developed during the past five years are based on the reduction of the correlational matrix by successive steps. The first factor loadings are determined and eliminated from the correlational matrix, giving a residual matrix. This process is continued for successive factor loadings until the elements of the last obtained residual matrix may be regarded as due to chance. The method outlined in this paper assumes the maximum number of factors m in the correlational matrix. The m factor vectors are solved for simultaneously. Once the m factor vectors are found, any vectors having only negligible factor loadings may be discarded.
The Scaling of Practice Data
Authors: Woodrow Herbert
Published: January 2006

It is shown that in certain cases practice data approximately meet the assumptions involved in Thurstone's method of absolute scaling. An application of the method was accordingly made in the case of four test performances practiced for 39 days by a group of 56 subjects. The manner in which the practice data were scaled is described by using the data on practice in anagrams as an illustration. Scaling had little effect upon the correlations between initial and final score, but produced marked changes in the apparent effect of practice upon individual differences and in the correlations between initial score and gain.
Some Aspects of Rashevsky's Theory of Delayed Reflexes
Authors: Householder A. S. , Amelotti E.
Published: January 2006

A closed solution of the integral equation obtained by N. Rashevsky, with the assumption that the inhibitory influence between centers is a constant, i.e., independent of the distance apart, is obtained. Furthermore, a more general kernel, representing a variable inhibitory influence, which in our case is a monotonic (increasing or decreasing) function of the distance between centers, is introduced. The resulting integral equation is solved and some properties of the solution discussed.
The Perceptual Factor
Authors: Thurstone L. L.
Published: January 2006

A further study of the perceptual factor, previously isolated in a factor analysis of a battery of fifty-six tests, is made in a manner designed also to determine whether the same seven primaries would be found in a different population of subjects and with another battery of tests. The tests are described, and the results of the analysis are given in detail. Much attention is given to the matter of the orthogonality of primary factors and to their psychological meaningfulness.
Weighting Systems for Linear Functions of Correlated Variables When There is no Dependent Variable
Authors: Wilks S. S.
Published: January 2006

When no criterion variable is available, the combination of tests or other variables by the use of multiple correlation is not possible. Three methods of combining variables are described mathematically, and discussed with reference to the linear combination of tests. Iterative computational schemes are outlined and illustrated.
An Abac for Determining the Mean Deviation of a Class from the General Mean
Authors: Dunlap Jack W.
Published: January 2006

The abac is presented with instructions for use.
The Relationship between Degree of Original Learning and Degree of Transfer
Authors: Gulliksen Harold
Published: January 2006

It has been repeatedly demonstrated that, in a learning situation involving a positive and a negative stimulus, the organism is frequently reacting to the relationship between stimuli rather than to the absolute characteristics of the positive or negative stimulus. For example, if in the original training series an animal has learned to react positively to a ten and negatively to a five centimeter circle, he w,ill, in the majority of trials, when confronted with a ten and a twenty centimeter circle, react positively to the twenty centimeter circle, that is, the larger of the two, and negatively to the ten centimeter circle which was formerly the positive stimulus. This is termed transposition of the relationship greater than from the training or original learning situation to the test or transposition situation.
Notes on the Rationale of Item Analysis
Authors: Richardson M. W.
Published: January 2006

There is increasing use of item analysis procedures for the improvement of objective examinations. The development of the procedures of item analysis has consisted chiefly of the invention of various forms of an index of association between the test item and the total test score. At least ten indices of item validity have appeared in various articles, which have been chiefly concerned with the relative effectiveness of the indices as devices for the improvement of tests. Since these indices of “item validity” are substitutes for or approximations to the ordinary coefficient of correlation between the item and the total test score, it may be useful to present certain deductions from simple correlational algebra. The present writer is of the opinion that the ingenuity displayed in the invention of new indices has outstripped the critical examination of the logical foundation for item analysis. The subsequent discussion is therefore concerned only with the underlying rationale of item analysis.
On the Use of Mathematics in Psychological Theory
Authors: Brown J. F.
Published: January 2006

For the readers of a journal devoted to the application of mathematics to psychological research it is scarcely necessary to spend much time in answering the question, “Why mathematics?” Science may best be defined as that set of postulates regarding experience to which the universal assent of competent observers may be obtained, plus the organization of such postulates into theories for which universal assent is likewise obtainable. Of all the propositions about nature those concerned with mathematics are most readily given universal assent. From this state of affairs the Kantian aphorism that a discipline is as scientific as it contains mathematics is entirely consequent. Kant himself doubted the applicability of mathematics to psychology and so was led to question the possibility of a scientific psychology. Fechher, as is well-known, thought differently and from Fechner‘s day the application of mathematical procedures has become an increasingly important part of psychological research until to-day we have a journal devoted to such application alone.
Centroid Orthogonal Transformations
Authors: Landahl H. D.
Published: January 2006

An initial transformation for facilitating the analysis of a factor problem is discussed. Such a transformation is used in the rotational procedure developed by L. L. Thurstone in an accompanying article.
Studies in Mathematical Theory of Human Relations. II
Authors: Rashevsky N.
Published: January 2006

In continuation of previous studies, relations are studied between two classes of population, of which one is characterized by a much greater ability to organize and supervise the productive activities of the other. Under some special and rather simple assumptions, it is shown that this kind of interreaction results first in an increase of the ratio of the cumulative results of productive activities for the two classes in favor of the first. With time, however, this ratio reaches a maximum and declines. An expression for the “life span” of such organized classes is obtained.

In the second section, a study is made of possible non-uniformities of spatial distribution of the population. Some possible applications are made to the theory of the variation of the ratio of urban to rural population, showing how that ratio may increase with increasing total population.
Studies in the Learning Function
Authors: Wiley L. E. , Wiley A. M.
Published: January 2006

The error function of the theoretical learning curve developed by Thurstone has been fitted to maze data from rats that have been subjected to cerebral cortical insult. There is a high degree of relationship between the number of errors necessary to complete learning as predicted from the curve and the experimental measure of learning, total-errors-minus-errors-first-trial. The procedure provides a method of analysis for individual learning records and it may be used to shorten the training period. The goodness of fit indicates that the underlying logic of the learning curve is plausible.
The Essential Conditions of Measurement
Authors: Scates Douglas E.
Published: January 2006

The basic conditions and characteristics of measurement are outlined. The concepts entering into the measurement must be operationally defined; there must be a satisfactory representation of the character to be measured, and a quantitative comparison between the observed degree of the character and some reference point or scale. A conception of measurement which is too narrow would unnecessarily restrict investigation in the fields of psychology and education.
The Relation Between Results Obtainable with Raw and Corrected Correlation Coefficients in Multiple Factor Analysis
Authors: Roff Merrill
Published: January 2006

This paper presents three theorems concerning the relation between results with obtained and corrected correlation coefficients in the Thurstone method of multiple factor analysis. (1) The rank of the correlational matrix, and thus the number of factors involved, is unaffected by correcting the obtained coefficients for attenuation. (2) The communality of a variable when the obtained coefficients have been corrected for attenuation is equal to the communality with obtained coefficients divided by the reliability coefficient of the variable. (3) The relationship is shown between the factorial matrix of a correlational matrix of raw correlation coefficients and the factorial matrix of a correlational matrix of corrected correlation coefficients, and a method of obtaining either of these factorial matrices from the other is indicated.
The Bi-Factor Method
Authors: Holzinger Karl J. , Swineford Frances
Published: January 2006

The Bi-factor Method of factor analysis is described and illustrated with a small group of fourteen tests. A detailed illustration is given of how the method may be modified to the case of overlapping group factors. It is advocated that the Bi-factor pattern in unmodified form be used to determine the adequacy of tests for the measurement of unitary traits.
The Relation of Primary Mental Abilities to Activity Preferences
Authors: Adkins Dorothy C. , Kuder G. Frederic
Published: January 2006

The relations of abilities, as measured by Thurstone's Tests for Primary Mental Abilities, to activity preferences, as measured by Kuder's Preference Record, are investigated for a population of 512 university freshmen. Ability profiles for contrasted groups on each preference scale reveal relatively slight overlapping between the two sets of measures, although the apparent trends are reasonable. The Pearson inter-correlation coefficients of all pairs of measures involved were determined. Implications of the findings in relation to theory and to educational and vocational guidance are indicated.
A Matrix Multiplier
Authors: Tucker Ledyard R.
Published: January 2006

A machine to expedite matrix multiplication has been developed by modifying the International Business Machines Corporation scoring machine. The principles and operation of the machine are described, and time and accuracy estimates are indicated.
A Study in Psychodynamics
Authors: Guilford J. P.
Published: January 2006

In seeking a suitable topic for the address at this annual event of the psychometricians, I tried to keep in mind the motto of our official publication, Psychometrika, to promote “the development of psychology as a quantitative, rational science.” The best that I have been able to do falls short of this ideal in two important respects. Although the material that I am to bring before you pretends to be quantitative, in the sense that measurements have been made, the problem has not been rationalized and the data have thus far yielded only to graphical treatment.
The Use of a Discriminant Function in the Treatment of Psychological Group Differences
Authors: Travers R. M. W.
Published: January 2006

A technique for determining a set of weights for the linear combination of a number of measures is applied to a concrete problem. The set of weights meets the criterion of maximum separation of the total scores of two different occupational groups.
Further Contributions to the Mathematical Theory of Human Relations
Authors: Rashevsky N.
Published: January 2006

In continuation of a previous paper, some consequences of the fundamental equations established there are studied. For some simple hypothetical cases it is shown how some of the parameters which enter in the equations governing the structure of the social group can be determined by means of those equations from actually observable data. Furthermore some general properties of the variation with respect to time of the fundamental distribution function, which enters in the equations, are derived.
Note on Computation of Bi-Serial Correlations in Item Evaluation
Authors: Dunlap Jack W.
Published: January 2006

By the use of an algebraic variant of the ordinary formula for bi-serial correlation, tables, and graphic devices, a time-saving systematic procedure for the computation of bi-serial correlation co-efficients is outlined for application to the evaluation of items of a test. A table of for arguments of p=.000 to p=.999 is given.
A Technique for Correlating Measurable Traits with Freely Observed Social Behaviors
Authors: Peters Charles C.
Published: January 2006

In much research in social psychology it is impractical to get quantitative measure of the degree of effectiveness of certain social behaviors, yet associates can sense that effectiveness sufficiently well to detect those who manifest the behavior in very high or in very low degree. This paper develops a technique of biserial correlation from wide-spread classes to deal statistically with such situations, develops standard error formulas for it, and points to a wide range of usefulness for this type of technique.
A Micro-Film Projector Method for Psychological Tests
Authors: Thurstone L. L.
Published: January 2006

Adaptations of the micro-film projection method to the administration of both individual and group psychological tests are described, together with newly designed auxiliary equipment. The author cites examples of the application of this technique, which can be adapted to a variety of testing situations and which seems to be of unusual promise because of the attention value of visual projection.
The L-Method
Authors: Toops Herbert A.
Published: January 2006

It is shown that the L-method is basic to test-building and to all combining of scores where the several sub-parts of a composite are weighted according to their respective standard deviations, i.e., with “equal gross score weights” or by “adding the several sub-scores.” With chiefly a listing adding machine, a few celluloid strips, and a master matrix table of L's, one may, in a fraction of the time and with equally good or even better practical results, easily duplicate, with test-building material most of the feats obtainable by multiple regression equations.
A Criterion for Significant Common Factor Variance
Authors: Coombs Clyde H.
Published: January 2006

Up to the present only empirical methods have been available for determining the number of factors to be extracted from a matrix of correlations. The problem has been confused by the implicit attitude that a matrix of intercorrelations between psychological variables has a rank which is determinable. A table of residuals always contains error variance and common factor variance. The extraction of successive factors increases the proportion of error variance remaining to common factor variance remaining, and a point is reached where the extraction of more dimensions would contain so much error variance that the common factor variance would be overshadowed. The critical value for this point is determined by probability theory and does not take into account the size of the residuals. Interpretation of the criterion is discussed.
A Table to Aid in the Computation of Fisher's “t” Function for Comparison of Two Means
Authors: Edgerton Harold A. , Starbuck Edmund O.
Published: January 2006

A table to facilitate the computation of Fisher's t function for the comparison of two means is presented. The derivations leading to the construction of the table, and the necessary instructions for its use, are given.
Note on Excitation Theories
Authors: Young Gaylord
Published: January 2006

Offner's demonstration of the excitation time equivalence, for all currents, of the theories of Hill and Rashevsky is here extended to a more general case which includes both. It is found that any system of this general type may be replaced by an equivalent one of the Rashevsky type, thus effecting considerable simplification in the mathematical detail.
The Reliability Coefficient
Authors: Kelley Truman L.
Published: January 2006

The reliability coefficient is unlike other measures of correlation in that it is a quantitative statement of an act of judgment,—usually the test maker's, — that the things correlated are similar measures. Attempts to divorce it from this act of judgment are misdirected, just as would be an attempt to eliminate judgment of sameness of function of items when a test is originally drawn up. A “coefficient of cohesion,” entirely devoid of judgment, measuring the singleness of test function is proposed as an essential datum with reference to a test, but not as a substitute for the similar-form reliability co-efficient.
Contributions to the Mathematical Theory of Human Relations: V
Authors: Rashevsky N.
Published: January 2006

Previously derived equations for the control of the behavior of one social group by another are developed further. Cases of interaction of three social classes are studied, and the variation of such an interaction with time is investigated. A previously derived equation for the ratio of urban to rural population is generalized, and a theory of interaction of industrial and agricultural classes is outlined. Some of the theoretically derived equations are compared with available sociological data and found in fair agreement.
An Appraisal of the Validity of the Factor Loadings Employed in the Construction of the Primary Social Attitude Scales
Authors: Ferguson Leonard W. , Lawrence Warren R.
Published: January 2006

In this article the authors examine the effect of including alternate test forms in a factor matrix upon the validity of the resultant factor loadings, finding that in this particular instance the effect is negligible. Comparisons of the factor loadings derived from matrices in which only one of the alternate test forms is included with those in which both forms are included reveal practically no difference in the magnitude of either the original or rotated factor loadings, or in that of the computed communalities.
Some Mathematical Remarks Concerning Boundary Conditions in the Factorial Analysis of Ability
Authors: Ledermann Walter
Published: January 2006

This paper is a mathematical supplement to the preceding paper by Professor Godfrey H. Thomson. It gives rigorous proofs of theorems enunciated by him and by Dr. J. Ridley Thompson, and extends them. Its basic theorem is that if a matrix of correlations is to be factorized without the aid of higher factors than s-factors (with n-s zero loadings), then the largest latent root of the matrix must not exceed the sum of the s largest communalities on the diagonal.
A further simplification of the multiple and partial correlation process
Authors: Griffin Harold D.
Published: January 2006

Formulas are derived for simplified computation of partial and multiple correlation coefficients, and generalized ton variables. Time required for computation is compared with other methods.
Scale Values Derived from the Method of Choices
Authors: Guilford J. P.
Published: January 2006

In many a psychometric problem, particularly in practical problems, the only data conveniently obtainable are the first choices given to certain stimuli among a list of stimuli that are available for selection. By assuming that such choices represent real comparative judgments, we may apply Thurstone's law of comparative judgments, extract experimental proportions from the numbers of first choices, and compute psychological scale values for the stimuli. Two procedures are proposed for estimating such proportions and examples of their applications are given. A procedure for allocating a meaningful zero point on the scale by the use of absolute judgments is explained and demonstrated. Suggestions are added for overcoming certain weaknesses and limitations of the method of choices.
A Theory of Learning and Transfer: I
Authors: Gulliksen Harold , Wolfle Dael L.
Published: January 2006

A rational theory of discrimination learning is developed for the special case in which the subject must discriminate between two stimuli which differ with respect to one variable such as size or brightness. It is shown that the previous equations developed by Gulliksen and Thurstone are special cases of the present one. It is predicted that the ultimate level of accuracy of the discrimination is inversely related to the difference, as determined psychophysically, between the two stimuli. Other implications of the theory for experimental work are presented.
Contribution to the Mathematical Biophysics of Error Elimination
Authors: Landahl Herbert D.
Published: January 2006

The theory of error elimination developed by N. Rashevsky is extended and generalized. Theoretical conclusions obtained are compared with the experimental data available.
A Method for Finding the Inverse of a Matrix
Authors: Tucker Ledyard R.
Published: January 2006

The problem of solving simultaneous linear equations is one that frequently confronts the scientist. Whenever it is desired to state the parameters as expressions of the constant terms of these equations, the problem resolves itself into the discovery of the inverse of the matrix of coefficients. The method here described gives a routine for the solution of this problem.
Some Preliminary Postulates on Stimulus-Perception, and Consequent Probability Distributions for Behavior
Authors: Gordon Robert Dean
Published: January 2006

A stimulus (or stimulus-complex) is pictured as giving rise to a random series of sensory nerve “pulses,” which manifest themselves in contractions of individual muscle fibers. Assuming the expected time-frequency of these pulses to be proportional to the intensity of the stimulus, probability distributions are computed representing the cumulative effect of these pulses on the state of the organism, that is, on its degree of awareness of the stimulus. Preliminary results suggest a modification of the Weber-Fechner formula for intensity discrimination for certain types of stimuli: the psychological scale to be measured by I1/2 instead of log I.
On a Shortened Method of Estimation of Mental Factors by Regression
Authors: Ledermann Walter
Published: January 2006

A shortened method of finding the regression for estimation of the scores on mental factors is presented. If the correlations among n tests are accounted for by r factors, the regression equation involves the inverse of an r × r matrix instead of the inverse of an n × n matrix. When r is much less than n, there is considerable saving in computational labor. A numerical example is presented to illustrate the method.
The Method of Equal Appearing Intervals
Authors: Urban F. M.
Published: January 2006

The results of J. P. Guilford's card-sorting experiment by the method of equal appearing intervals are analyzed mathematically. The constants of the psychometric functions are obtained by processes analogous to the constant process. When these constants are determined (a) independent of the supposition that the series of groups into which the cards were sorted is quantitative in character and (b) under this supposition, good agreement is found between them. Guilford's results agree with Weber's and Fechner's laws in both cases.
A Computational Short Cut in Determining Scale Values for Ranked Items
Authors: Barnhart Edward N.
Published: January 2006

In a study of color preferences, Winch, using the order of merit technique, adopted as a measure of group preference an index equivalent to the average rank assigned by N individuals. He awarded to the specimen in first place in each array a value of 1, to second place specimens a value of 2, and so on, summed the values awarded to each item for the N arrays and used their relative magnitudes as a measure of group preference. These values divided by N would give the average rank of the specimens.

In the computation of scale values from ranked items by the method developed by Thurstone, the first step is the determination of the frequency with which each item is preferred to every other for the N arrays. In this method it is assumed that ranked data yield comparative judgments and that they can be treated in the same manner as data from paired comparisons. The first specimen in a ranked order is considered preferred to all specimens following it, and similarly for other specimens.
A Factor Analysis of Mechanical Ability Tests
Authors: Harrell Willard
Published: January 2006

The intercorrelations of thirty-seven variables, including the Minnesota battery of “mechanical ability” tests, the seven MacQuarrie tests of “mechanical ability,” O'Connor's Wiggly blocks, and the Stenquist picture-matching test, were analyzed by Thurstone's centroid method. Five factors, Perceptual, Verbal, Youth, Manual Agility, and Spatial, were taken out. Factors prominent in so-called mechanical ability tests are the Spatial and Perceptual ones with Mac-Quarrie's dotting test significantly high in the Manual Agility factor. Each of the factors can be measured with group pencil-and-paper tests.
Factorial Invariance and Significance
Authors: Young Gale , Householder A. S.
Published: January 2006

It is shown that invariance requirements remove the indeterminacy in factor determination and lead to an integration of factorial studies with promise of considerable reduction in computational labor. The selection of significant primary factors is discussed, with special reference to Thurstone's simple structure criterion.
Scoring Formulas and Probability Considerations
Authors: Calandra Alexander
Published: January 2006

Bayes' theorem of inverse probability is made the basis of a general equation for scoring objective examinations. The equation so obtained is evaluated by assuming a binomial distribution of examinee knowledge and guessing tendency. A graphical illustration of the application of this equation to a hypothetical test situation is presented. The limitations inherent in the use of Bayes' theorem make it inadvisable to recommend the practical use of the equation unless future experimental evidence indicates an increase in scoring validity which more than compensates for the increase in scoring difficulty.
The Application of Sheppard's Correction for Grouping
Authors: Ferguson George A.
Published: January 2006

This paper attempts to show in a non-mathematical way the influence of grouping on standard deviations and correlations, and advances empirical evidence to illustrate with what accuracy values corrected for grouping by Sheppard's correction approximate to values obtained from ungrouped data when the distributions are continuous. This enquiry gained its initial stimulus from the observation that many standard deviations and correlations reported by students of psychology and education are uncorrected for grouping and that frequently errors attributable to the grouping of data are not small when compared with errors of sampling.
Complex Analyses of Variance: General Problems
Authors: Green Bert F. , Tukey John W.
Published: January 2006

Problems in applying the analysis of variance are discussed. Emphasis is placed on using the technique to understand the data. The scale of the dependent variable is important for the analysis. Crossed and nested categories must be recognized. The error terms in the analysis depend on whether the classes of each independent variable are (1) all out of a few or (2) a few out of many. To simplify the analysis, mean squares should be aggregated with their error term when they are less than twice its size. An illustrative example is discussed in detail.
Determinantal Methods in Latent Class Analysis
Authors: Madansky Albert
Published: January 2006

Some extensions of the existing determinantal methods for solving the accounting equations in latent class analysis are presented. These extensions cover more cases than previous methods, give rise to new sufficient conditions for identifiability of the latent class model, and give insight into the necessity of various sufficient conditions for identifiability. These implications to the identifiability problem are discussed.
Matrix Formulation of Deuel's Rotational Method
Authors: Baggaley Andrew R.
Published: January 2006

Deuel's rotational method for factor analysis is translated from vector algebra to matrix algebra. A computational example is presented using Deuel's nomogram.
The Factorial Interpretation of Test Difficulty
Authors: Ferguson George A.
Published: January 2006

This paper discusses the influence of test difficulty on the correlation between test items and between tests. The greater the difference in difficulty between two test items or between two tests the smaller the maximum correlation between them. In general, the greater the number of degrees of difficulty among the items in a test or among the tests in a battery, the higher the rank of the matrix of intercorrelations; that is, differences in difficulty are represented in the factorial configuration as additional factors. The suggestion is made that if all tests included in a battery are roughly homogeneous with respect to difficulty existing hierarchies will be more clearly defined and meaningful psychological interpretation of factors more readily attained.