High-speed 2-D and 3-D animation on the IBM PC/XT/AT

This article describes programs for performing high-speed two-dimensional (2-D) and three-dimensional (3-D) animation on IBM PC/XT/AT and compatible machines that use the color/graphics adapter. Machine language routines interfaced through BASIC allow the user to store screen images in memory as they are created by user software and then to display the sequence of images at rates of up to 60 frames per second. A BASICA 3-D graphics editor that can be used with the routines permits the user to create wire-frame objects and to move them about rigidly in conceptual space while projecting them onto the display screen. These programs should find application in the study of visual perception and cognition.     

A perception experiment with time-critical graphics animation on the World-Wide Web

The World-Wide Web offers a potentially interesting tool to collect data from a large and heterogeneous audience. While questionnaires have become rather common on the Internet, its potential reaches far beyond text processing. In principle, it is possible not only to perform interactive, dynamic experiments on the Web, but also to include graphical animation and time-critical responses, such as reaction times. We implemented a visual motion extrapolation task on the Web using the programming language Java, which can be interpreted by standard Web browsers such as Netscape or Internet Explorer. The data collected with this method turned out to be reliable and differed little from data obtained in a controlled laboratory setting, with the exception of conditions with fixation instruction. Thus, the Web can, generally speaking, be used for data collection of large sample sizes. The strengths and weaknesses of dynamic visual simulation experiments on the Internet are discussed.     

The use of computer graphics animation in motion perception research

The advantages and limitations of using computer-animated stimuli in studying motion perception are discussed. Most current programs of motion perception research could not be pursued without the use of computer graphics animation. Computer-generated displays afford latitudes of freedom and control that are almost impossible to attain through conventional methods. There are, however, limitations to this presentational medium. At present, computer-generated displays present simplified approximations of the dynamics in natural events. We know very little about how the differences between natural events and computer simulations influence perceptual processing. In practice, we tend to assume that the differences are irrelevant to the questions under study and that findings with computer-generated stimuli will generalize to natural events.     

An experimental psychology laboratory system for the Apple II microcomputer

A system for on-line control of experiments is described that uses the Apple II microcomputer and requires no knowledge of programming. This system, APT, is used to construct test files, randomize stimulus order, and conduct experiments. Construction of an experiment is very easy through use of an interactive program. APT provides powerful options for controlling stimulus duration, feedback, and response type. Programs are available to conduct either a sequence of tests without any experimenter present or a single experiment. Over 200 subjects, ranging from 18 to 86 years of age, have completed a battery of cognitive and abilities tests using the system.     

Writing high-quality statistical software for Apple II microcomputers

The purpose of this paper is to describe some principles and techniques that programmers should consider when trying to improve or create a statistical package. Four computational issues are discussed: accuracy, speed, computing probabilities, and error trapping. A single-array data structure is proposed for use within the program. Several other input-output issues are covered, including menus, command languages, questions, data input and editing, CRT and printer formatting, and graphics.     

An Apple II package for computer-assisted telephone interviewing

This paper describes an Apple II (an Apple-compatible) microcomputer package for a computer-assisted telephone interviewing (CATI) system. This system generates random telephone numbers within any number of exchanges that the user supplies, automatically dials the telephone, prompts the interviewer with each question, and records and permanently saves each response. It also provides a printed copy of the collected data by frequency of response in each question category. The Apple II CATI package is readily available, inexpensive, and easy to program in the BASIC language.