A deglitching circuit for the AA50 D/A converter

Switching transients or “glitches” are frequently encountered in signal processing applications involving digital-to-analog (D/A) conversion. A low-cost “deglitching” circuit is described and implemented for the Digital Equipment Corporation AA50 D/A converter option on the PDP-8/e minicomputer. Switching transients were eliminated using a noninverting, unity-gain sample-and-hold circuit (employing Datei System’s SHM-IC-1). Switching transients were reduced to below-noise levels across a wide range of output levels and sampling rates.     

An introduction to microcomputer networking concepts

This paper presents a brief history of the use of internal computer networks, an introduction to networking concepts and topology, and suggestions regarding a possible system for use in a psychology laboratory. Considerations about the design and use of a microcomputer network are discussed.     

A self-contained microcomputer system for psychological testing

This paper describes a newly available microcomputer system for the on-line administration, scoring, and interpretation of psychological tests. User response to the system is reported. Results of a validity study of the system’s Minnesota Multiphasic Personality Inventory interpretative program are presented.     

Effects of visual familiarity on “same” and “different” decision processes

An experiment was conducted in which subjects matched upper and lower case versions of well-known abbreviations, such as BBC and etc, and meaningless controls. “Same” RT showed a familiarity effect for upper case versions of abbreviations such as BBC and GPO, but not for the lower case versions bbc and gpo. The converse did not occur for abbreviations such as etc, which were thought to occur most frequently in lower case. The “different” RT was inhibited by familiarity, with pairs such as IBM GPO being classified less rapidly than their lower case versions or controls. These effects occurred for subjects instructed to report “No” for “same” displays and “Yes” for “different” displays as well as for subjects given a conventional decision-report assignment. Some implications of these results for an account of the manner in which familiarity affects graphemic comparison processes are considered.     

Inexpensive microcomputer systems for research and instruction: A dream or reality?

This paper presents a detailed introduction to two microcomputer systems useful for research and instruction. The systems are ready for immediate use, fully assembled, and require no knowledge of electronics. They also possess the high-level programming language, BASIC, which can be easily learned by researchers and students. The application of microprocessor technology and mass production has allowed the cost for a single microcomputer to be reduced to about $600. At this price, virtually any psychology department or individual researcher can begin to employ computer technology in psychological research and instruction. The hardware specifications, software characteristics, criteria for selection, and possible applications of these systems are considered, with emphasis on use in psychological applications.     

A multipurpose activity platform utilized in the open-field setting

An automated multipurpose activity platform (MAP) that can be used to measure activity in the horizontal plane is described. Detection of the position of a small-bodied animal is based on completion of an electronic circuit in one or several cells of a 21 by 21 matrix below the floor. The MAP is constructed on the basis of an 11 by 11 matrix, but, through electronic averaging, operates functionally on the basis of a 21 by 21 matrix. The MAP has no built-in data storage facility and needs to be interfaced with a recording system. The system has been successfully utilized in measuring open-field activity of the rats.     

Organizational preparedness for change: Staff acceptance of an on-line computer-assisted assessment system

An on-line assessment system is briefly described. Previous positive evaluation studies are summarized. Results of studies of staff acceptance and staff preparedness for change are reported. Findings are interpreted in terms of the need for planning for change. Implications related to the acceptance of other on-line computer systems in psychology are discussed.     

Memory for music

Subjects created imaginal interpretations of classical music passages in accordance with themes which were either concrete and comprehensible or abstract and difficult to comprehend. Recognition memory for the musical passages was found to be superior in the former condition. The results support the hypothesis that meaningful interpretation of stimulus material is a major determinant of memory accuracy. The implications of the results for comparisons of music and language are also discussed.     

Comparative evaluation of the Job Club program with welfare recipients

About 1000 WIN welfare clients were selected in five cities: Harlem, New Brunswick, Milwaukee, Wichita, and Tacoma, and half were randomly assigned to the Job Club program. Of the continuing clients, 87% of the Job Club sample obtained jobs vs 59% of the Control sample at the 12-month follow-up and 80 vs 48% at 6 months. The Job Club was more effective in each of the five cities, for men and women, for high school graduates or dropouts, for blacks, whites, and Spanish, for handicapped or nonhandicapped, veterans or nonveterans, the young and the older, and for those required to participate as well as those who volunteered. The jobs obtained by the Job Club clients were comparable to the Control clients' jobs in terms of mean salary, full-time status, and type of job, and were more likely to be enduring, nonsubsidized, and obtained by the job-seeker's own efforts. Job Club members obtained employment in a median of six sessions (mean of 11); 90% obtained jobs within 23 sessions. Follow-up questionnaire data indicated comparable job retention in the two samples but slightly greater advancement and job satisfaction for the Job Club clients. The method appears to assure employment to virtually all participating welfare clients.