Test difficulty, reliability, and discrimination as functions of item difficulty order.

In an attempt to evaluate the often stated rule that test items should be arranged in an increasing order of difficulty, the effect of item difficulty order on total test reliability, difficulty, and discrimination was investigated in a series of 4 experiments. Each experiment involved a comparison of 2 or more tests, containing the same 40 items and differing only with respect to the order of those items. The differently ordered forms did not, in any of the experiments, differ significantly in test difficulty or test reliability. The results with respect to discrimination were not as clear-cut. However, the results tend to lead to the conclusion that item difficulty order on a power test of facts and principles given in the normal college classroom will not significantly affect these 3 test statistics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group performance as function of task difficulty and the group's awareness of member satisfaction.

Investigated the hypothesis that group effectiveness increases with increased member awareness of group satisfaction, and that this effect is greater for difficult than for easy tasks. 5-person groups attempted 3 tasks differing in difficulty, under 3 conditions of satisfaction feedback: no feedback, overt feedback, and covert feedback. In the overt condition, Ss publicly indicated their satisfaction with the problem-solving process, whereas in the covert condition their satisfaction was indicated anonymously. The results supported the hypothesis. It was suggested that valid communication of satisfaction leads to more complete use of members' contributions, and hence improves performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Familiarity and lexicality as determinants of the generation effect.

Two experiments addressed the question of whether representation in the mental lexicon is a sufficient condition for obtaining the generation effect. Contrary to an earlier report (Nairne, Pusen, & Widner, 1985), our experiments showed that low-frequency words did produce significant retention advantages when generated, but only when items were rated as highly familiar to the subjects; when low-frequency words were recognized as words but were rated low in familiarity, no generation effect emerged. Overall, our results support the position that lexical representation is neither a necessary nor a sufficient condition to produce the generation advantage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perception and discrimination as a function of stimulus orientation: The "oblique effect" in man and animals.

A review of both behavioral and neurophysiological studies of orientation preferences indicates that performance for a large variety of perceptual tasks is superior for stimuli aligned in horizontal or vertical orientations, as compared to stimuli in oblique orientations. This phenomenon appears in the human adult and child and throughout the animal kingdom. Neurophysiological mechanisms for orientation analysis have been found in the higher visual pathways of many animals, and the suggestive evidence is compelling that these mechanisms underlie the orientation preferences reported behaviorally. Additional methods for determining the cause of these effects are suggested. (11 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anxiety as a function of intrinsic-extrinsic job orientation: The presence or absence of observers, and task difficulty.

Divided 92 intrinsically and 96 extrinsically job-oriented male undergraduates into 4 comparable subgroups. 2 subgroups worked on simple anagrams, 1 alone and 1 observed by 2 individuals of higher status. The other 2 worked on difficult anagrams under the same 2 conditions. Felt anxiety and perception of task difficulty ratings were elicited along with reactions toward the experimental conditions. The intrinsically oriented expressed more uneasiness than the extrinsically oriented while being observed on the difficult anagrams. They also tended to perceive the task as more difficult when observed than when alone, while the opposite was true for the extrinsically oriented. The importance of job orientation in the reaction to the presence or absence of os is discussed. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decreased discrimination as a function of increased drive.

In 2 samples of psychiatric patients, an increase in drive induced by gripping a hand dynamometer led to a decrease in discrimination characterized by a reduction in an appropriate response at its training stimulus. The drive also facilitated generalized dominant responses and did not increase anxiety. It was concluded that a decrease in appropriate behavior can result from an increase in a nonaversive drive. The results were in accord with a theoretical account utilizing constructs from Hull-Spence theory and including a lowered reaction potential ceiling. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning and generalization of GSR as a function of awareness.

"This study was essentially a replication of… (an) experiment on the unconscious conditioning of autonomic responses. When… (the previous) methods of data analysis were used, their results in general were confirmed." Limitations and critique of the previous methodology is offered, and its effect on the results obtained is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mental test performance as a function of payoff conditions, item difficulty, and degree of speeding.

Using analysis of variance and factor analysis, the performance of 41 psychology students on the Michill General Ability Test was analyzed. "… the experimental manipulation of payoff conditions, difficulty, and speeding can introduce substantially important new factors of which the test constructor may or may not be fully aware… . The commonly held belief that, for all practical purposes, test directions provide an adequate control of the Ss motivation and/or mental set is clearly untenable." (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Treatment outcome as a function of follow-up difficulty in substance abusers.

Studied 150 consecutive male alcoholic and drug addict admissions to inpatient treatment at a VA medical center to determine if Ss who were more difficult to follow up also had poorer posttreatment outcomes. Of the original sample, 144 Ss were successfully followed up 6 mo from the date of admission, for an overall completion rate of 96%. Of that total, 2 were found to be deceased, leaving complete and valid information for 142 (95%). Ss were grouped according to the number of attempts necessary to complete follow-up. Comparisons on 18 measures indicated essentially no difference in the outcome status of Ss harder to follow up than those more easily contacted. Subsequent analyses of the alcoholic and drug addict samples individually yielded similar results. Further analyses indicated that the results obtained were not a function of the length of time spent in treatment or the length of time between treatment discharge and follow-up. Results are discussed in light of their importance in the interpretation of follow-up evaluations. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bi-stability of movement coordination as a function of skill level and task difficulty.

This study investigated whether the level of practice interacts with the initial conditions (here manipulated as preparatory movements) and task difficulty (ball angular velocity and friction) in determining the stability of movement coordination for a roller ball motor task. Practice level and task difficulty were manipulated as two control parameters that theoretically were hypothesized to change the threshold for the transition between task success and failure. The findings showed bi-stability and hysteresis in the coordination mode as a manifestation of dependence on the initial conditions. The transition from failure to success in the roller ball task as a function of practice time can be modeled as a saddle-node bifurcation corresponding to a first order phase transition. It is proposed that task difficulty acts as a control parameter that is a dual to skill level and that also effectively compensates for practice time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dyadic performance on two tasks as a function of task difficulty, work strategy, and member ability.

Replicated the manipulation of divided and shared labor used in previous studies by the present author (see PA, Vol 49:1265 and Vol 51:2005), while varying task difficulty and member ability in order to examine their combined effects upon dyadic performance on 2 tasks: analogies and crossword puzzles. Ss were 72 US Army enlisted men; 54 had a mean of 12.4 yrs of education, and 18 were technicians with a mean of 3.6 yrs of higher education. Dividing labor was found to be more efficient in terms of man-hours to a performance criterion, but sharing labor was more effective (i.e., it produced greater total performance). The efficiency effect was more pronounced on the analogies tasks, while the effectiveness findings were more pronounced on the crossword puzzles. Results occurred across task difficulty and group ability. The hypothesis that task difficulty would indicate the importance of ability redundancy on group performance was not supported. Differences in the performance curves for the 2 tasks are discussed in terms of the role of feedback regarding the adequacy of a response to the task. It is suggested that a distinction be made between task difficulty and task complementarity when considering the effects of ability redundancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing differences as a function of item difficulty in verbal analogy performance.

Research based on componential models of analogical reasoning has typically been based on relatively easy items. Differences between individuals have been ascribed to execution efficiency of component processes within a single model. In the present study, we evaluated processing of verbal analogies by recording eye fixation patterns during problem solution. Problems represented a broad range of levels of difficulty. The findings on easier problems replicated previous work. On more difficult items, however, high verbal individuals tended to adapt their processing strategies to a much greater extent than did low verbal students. Skill differences were not attributable to initial encoding of the item, but rather to more thorough re-encoding of the stem and answers by the high verbal subjects. Current models cannot account for all individuals on all items when experimental items are more representative of aptitude test items. Instead, more complex models that incorporate both person and item characteristics need to be developed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Judgements of discrimination as a function of group experience and contextual cues.

The personal/group discrimination discrepancy (PGDD) refers to the tendency to report more discrimination against one's group than oneself. The authors demonstrated that the magnitude of both personal and group discrimination judgments depend on group experience and cue availability in the judgment context, using college students as Ss. For men, who have relatively little experience with gender discrimination, the addition of contextual cues that highlighted workplace discrimination produced lower estimates of both personal and group discrimination. For women, who are familiar with discrimination in general and workplace discrimination in particular, contextual cues produced higher estimates of group discrimination, but lower estimates of personal discrimination. The authors contend that these differences reflect realistic assessments by participants of their group's experiences with discrimination. Implications for conceptualizing the PGDD are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acquisition of a spatial discrimination by rats as a function of age.

144 female albino Sprague-Dawley rats, equally divided among 3 levels of food deprivation, were given 10 trials/day on a spatial discrimination until 1 errorless day occurred. 1/2 of the Ss were 33 days old (juveniles) when training began; the other Ss were between 100 and 120 days old (adults). Results show that juveniles learned more slowly than adults, and Ss given a smaller daily food ration learned in fewer trials. The age-related difference in learning rate was interpreted to be a consequence of relatively ineffective inhibitory processes among the juveniles in view of the associated differences in sequence of choices and other behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Schizophrenic discrimination learning as a function of aversive social and physical reinforcement.

60 schizophrenics comparable in important psychopathological variables (e.g., Inpatient Multidimensional Psychiatric Rating Scale and the Premorbid History-Phillips Prognostic Rating Scale) to Ss in other similar studies were compared on a discrimination learning task with noxious physical reinforcement (intense white noise at 91–94 db) under experimenter (E)-present conditions with motivational instructions and E-absent conditions with neutral instructions. Aversive reinforcement was delivered on a response contingent basis for avoidance and escape training under both social conditions. Long-term effects were evaluated 3 consecutive learning tasks: before, during, and following the 6 reinforcement conditions. Results provide strong confirmation that social factors in the E–S relationship determine the speed of learning throughout. Regardless of physical punishment or the reinforcement paradigm (avoidance or escape), Ss learned significantly faster in the E's presence with motivational instructions both during and after the reinforcement phase. The theoretical implications of what is called biological motivation were found to be insufficient grounds for ordering the data. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Form discrimination performance of schizophrenics as a function of social censure, premorbid adjustment, chronicity, and diagnosis.

Tested the social censure hypothesis by presenting neutral and censure stimuli to 160 male 20-60 yr. old schizophrenic-paranoid inpatients in 10 experimental subgroups. Results support previous disconfirmatory studies which found that stimulus content is a minor factor in the explanation of the schizophrenic performance deficit. The similarity in performance of schizophrenics and other comparable hospitalized groups is discussed in relation to the possible confounding processes elicited by the form discrimination task. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Young children's phonological awareness and nonword repetition as a function of vocabulary development.

The role of vocabulary growth in the development of two reading-related phonological processes was examined. In Experiments 1 and 2, 4- and 5-year-olds and a sample of first graders performed better on phonological awareness tasks for word versus pseudoword stimuli, and for highly familiar versus less familiar words. Three- and 4-year-olds in Experiment 3 performed better for words with many versus few similarly sounding items in a listener's lexicon. Vocabulary was strongly associated with nonword repetition scores for 3- to 5-year olds. The shared variance of this association was accounted for by phonological awareness measures and did not appear to be due to phonological short-term memory, as previously argued. The author proposes that vocabulary growth, defined in terms of absolute size, word familiarity, and phonological similarity relations between word items, helps to explain individual differences in emerging phonological awareness and nonword repetition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of item format on item discrimination and difficulty.

Studied the effects of item stem orientation (positive-negative), structure (open-closed), and inclusive alternatives on item difficulty and discrimination. Data were obtained from 1,124 undergraduates taking a regularly scheduled test. Results indicate that item difficulty was critically affected by all 3 independent variables with no interactions and that item discrimination was affected by the use of an inclusive alternative with a significant interaction between orientation and stem structure. Suggestions are made with respect to effective item-writing strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning of verbal behavior as a function of awareness, need for social approval, and motivation to receive reinforcement.

This investigation evaluated the effects of awareness, need for social approval, and motivation to receive reinforcement on verbal conditioning. 61 male college students were reinforced with "good" for constructing sentences beginning with "I" or "we." Awareness and reinforcement motivation were assessed by an intensive postconditioning interview; need for social approval was measured by the Marlowe-Crowne Social Desirability scale. Ss aware of a correct response-reinforcement contingency gave more "I" and "we" sentences than Unaware Ss, who showed no evidence of learning. Aware Ss motivated to receive reinforcement gave more "I" and "we" sentences than unmotivated Aware Ss. Contrary to expectation, need for approval was not related to Ss' reinforcement motivation or performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)