The Observer Video-Pro: New software for the collection, management, and presentation of time-structured data from videotapes and digital media files

The Observer Video-Pro is a system for collecting, managing, analyzing, and presenting observational data. It integrates The Observer software with time code and multimedia hardware components. It extends the functionality of a conventional real-time event recording program in various ways. Observational data can be collected, reviewed, and edited with synchronized display of the corresponding video images. For optimal visual feedback during coding, one can display the video image in a window on the computer screen. Video playback from either a VCR or a digital media file can be controlled by the computer, allowing software-controlled jog, shuttle, and search functions. Besides a wide range of VCRs, The Observer Video-Pro supports all major digital video file formats. The software allows the user to summarize research findings in numerical, graphical, or multimedia format. One can create a time-event plot for a quick glance at the temporal structure of the observed process, or run specific analysis procedures and generate reports with statistics. An Event Summary function is available for exploratory and qualitative analysis. Video material can be summarized in a Video Play List, which allows on-screen summary presentations or the creation of highlight compilations on tape, CD, or other media. Video images can be captured and saved as disk files, for use as illustrations in documents, slides for presentations, and so forth. In this paper we describe the design and operation of the system, illustrated with a case study from research on Repetitive Strain Injury (RSI).     

The Measuring and Observation Tool in Sports

The Measuring and Observation Tool in Sports (MOTS) has been designed to facilitate the systematic observation of sports. It is a user-friendly tool developed to help researchers observe, codify, register, and analyze any situation that occurs in a natural or habitual context in which behaviors are spontaneous. Users can define up to 12 mutually exclusive code sets and up to 120 different behaviors to facilitate data collection and can work with any observational data type: event sequences, event sequences over time, state sequences, interval sequences, or multievent sequences. MOTS plays digital video files, which allows for video and taxonomic tools to be displayed on the screen at the same time. The observations are registered automatically, including the time and duration of the event, in frames and seconds simultaneously. Furthermore, the data analysis feature allows the user to calculate the percentage of intervals, the frequency distributions, and the conditional probabilities.     

PC operating system for measuring discrete biological responses during classical conditioning

A software package, written in C source code for MS-DOS 5.0 or higher IBM-compatible computers, was developed for the classical conditioning of discrete biological responses. The program’s primary functions include collecting and storing conditioning parameters, controlling presentation of stimuli, transforming discrete analog responses into dependent measures (e.g., CR frequencies and various measures of response topography), and generating data sets for use with commercial PC statistical packages. These functions were implemented in a windows-based user interface to increase the experimenter’s ease of use and to maximize efficiency in performing experimental procedures. Scrollable windows provide detailed visual displays that permit monitoring responses during conditioning and a review of each trial after the session is over. Additional software tools aid the visual inspection of response topographies, data manipulation, and calibration of the experimental apparatus. An overview of the system, its design objectives, and the user interface is presented.     

Using hardware interrupts for timing visual displays and reaction-time key interfacing on the Commodore 64

The use of hardware interrupts for presenting and timing visual displays and for controlling reaction timing on the Commodore 64 is described. The three sources of interrupts discussed are reaction-time keys interfaced through the user port to on-board hardware timers, the alarm of the 60-Hz real-time clocks, and the video raster. In a demonstration program, these interrupts are used to measure display durations, to change screen displays, and to coordinate the onset of reaction timing with the onset of screen changes. In addition, an externally generated interrupt caused by a keypress is used to control reaction timing independently of CPU operations.     

Tachistoscopic presentation and millisecond timing on the IBM PC/XT/AT and PS/2: A Turbo Pascal unit to provide general-purpose routines for CGA,Hercules, EGA,and VGA monitors

A review of the literature on adopting microcomputers for use in tachistoscopic research paradigms illustrates the need for a comprehensive package to effectively deal with the wide variety of video displays and microcomputers used in experimental settings. In addition, because of the large number of possible configurations created when video displays and computer systems are combined, there is a need to be able to efficiently drive any such combination without rewriting program code. A Turbo Pascal unit is presented to provide standard tachistoseopic routines compatible with monochrome, CGA, Hercules, EGA, and VGA video technology. Procedures that synchronize both text and graphics mode stimuli with the vertical retrace pulse are given, as are routines to provide access to a timer with better than millisecond precision. Pascal code is described that will run on the IBM PC, XT, AT, or PS/2, as well as on any compatible machine. The versatility of the unit allows the experimenter to use generic video and timer commands that will automatically adapt at run time to the system that is being used, without further experimenter intervention.     

The Observer: A software system for collection and analysis of observational data

The Observer is a general-purpose software package for event recording and data analysis in behavioral research. It allows any IBM-type personal computer to serve as an event recorder. In addition, The Observer can generate dedicated event-recording programs for several types of non-IBM-compatible portable and hand-held computers and transfer files between the PC and such computers. The user specifies options through menus. The configuration can be either used directly for event recording on the PC or passed on to a program generator that creates a program to collect data on a hand-held computer. Observational data from either type of computer can be analyzed by the program. Event-recording configurations can be tailored to many different experimental designs. Keys can be designated as events, and modifiers can be used to indicate the limits of an event. The program allows grouping of events in classes and distinction between mutually exclusive versus nonexclusive events and duration events versus frequency events. Timing of events is accurate to 0.1 sec. An on-line electronic notepad permits notes to be made during an observation session. The program also includes on-line error correction. User comments as well as independent variables can be stored together with the observational data. During data analysis, the user can select the level of analysis and the type of output file. The Observer calculates frequency of occurrence and duration for classes of events, individual events, or combinations of events. For analysis of concurrence, one can select the number of nesting levels and the order of nesting. Output can be generated in the form of sorted event sequence files, text report files, and tabular ASCII files. The results can be exported to spreadsheet and statistical programs.     

RAP: A computer program for exploring similarities in behavior sequences using random projections

A computer program (RAP, for random projection) for exploring similarities between and within sequences of behavior is presented. Given a time window of a sequence, the program calculates a signature, a real-valued vector that is a random projection of the contents of the window (i.e., the codes occurring within it and their relative location, or onset and offset times) into an arbitrary K-dimensional space. Then, given two different time windows from the same sequence or from different sequences, their similarity is computed as an inverse function of the Euclidean distance between their respective signatures. By defining moving (overlapped or not overlapped) windows along each sequence and calculating similarities between every pair of windows from the two sequences, a map of similarities or possible recurrent patterns is obtained; the RAP program represents them as gray-level lattices, which are displayed as mouse-sensitive images in an HTML file. Computation of similarities is based on the random projection method, as presented by Mannila and Seppänen (2001), for the analysis of sequences of events. The program reads sequence data files in Sequential Data Interchange Standard (SDIS) format (Bakeman &; Quera, 1992, 1995a).     

A real-time satellite system based on UNIX

One solution to the difficulty of running real-time applications under UNIX is to develop the application programs on an available UNIX system and execute them on a dedicated satellite processor. This combines the advantages of a powerful timesharing operating system with the real-time capabilities of a single-process system. PARASITE, a real-time satellite system, provides tools for developing the application program on the host and executing it on a satellite. A host utility serves to invoke the standard UNIX C compiler and link its output with the PARASITE library. The PARASITE library consists of routines that mimic the standard library and routines that read and write the real-time peripherals. PARASITE currently supports digital inputs and outputs, asynchronous serial-line interfaces, program-mable real-time clocks, and analog-to-digital and digital-to-analog converters. Another PARA-SITE utility downloads the object code of the user program and PARASITE support code into the satellite, where it runs independently. Once the application routine is executing on the satellite, it controls the satellite processor at all times and is continuously available for servicing hardware-generated interrupts. When a real-time peripheral interrupt routine is invoked by a hardware interrupt, it sends a software signal to the user program, in addition to processing the interrupt. This allows the user program to perform additional tasks that are specific to the application. All data to be permanently stored must be transferred to the host. Since the satellite has no direct access to the resources of the host, a process running on the host receives the data and manages files. PARASITE provides packet driver routines on both the host and the satellite, which together handle the data transmission protocol.     

ODAP: a stand-alone program for observational data acquisition

A software program written to collect real-time, observational data is described. The flexible program allows customized behavior codes and observational durations and simultaneously records both timed and counted events. The data are collected by means of single keystrokes, automatically stored to disk with 100th of a second resolution and summarized for each observational session. The program’s database files are dBASE III PLUS compatible and may be browsed, edited, or converted to ASCII files from the program’s main menu. Field testing demonstrated the efficiency and interobserver reliability of the program (for frequency,r=0.81; for durational behaviors,rs=0.89 and 0.96). The software operates on IBM XT/AT/PS 2s and most clones with PC/MS DOS version 2.0 or greater.     

Color coding information: assessing alternative coding systems using independent brightness and hue dimensions

Can independent dimensions of brightness and hue be used in a combined digital information code? This issue was addressed by developing 2 color-coding systems and testing them on informed and naive participants in signal beam detection and classification experiments for simulated sonar displays. Each coding system's results showed both groups efficiently used encoded information that varied simultaneously along the 2 dimensions of brightness and hue. Findings support the proposed procedures for developing color information codes and the validity of such information codes across different populations. Applied significance of these results is provided by the test of principled methods of color-code construction and the demonstration that extending the information content of user interfaces beyond 1 dimension is feasible in practice.     

VIDEOLOGGER: A computerized multichannel event recorder for analyzing videotapes

A microcomputer-assisted system that permits multiple events to be coded from videotape to a common time base is described. The system allows an operator, by pressing a button, to record the onset and offset times of any number of events. It requires a video recorder, an Apple II microcomputer, a John Bell 6522 timing card, and a pair of switches. The software package consists of five programs: one to make timing signals on the videotape, one to record the onset time and duration of the operator’s buttonpresses, one to read and print the coding data from disk, one to operate the timer, and one to process the compiled code used in the software package. All necessary wiring diagrams are shown. Software is available gratis from the authors on request.     

Signal-processing software for teaching and research in psychoacoustics under UNIX and X-Windows

A package of software is described that generates, analyzes, stores, and displays sampled waveforms. The package is designed for use under UNIX and includes C source code, UNIX manual pages, and tutorial documents. The programs interact via UNIX pipes using an ASCII-text data format, which enables the user to view the data in numerical form as well as through the use of plotting programs. Among many other functions, the programs can do the following: efficiently generate linearphase FIR filters with arbitrary transfer functions; generate impulse responses for rectangular rooms of specified dimensions; convolve waveforms with each other; perform Fourier transformation and inverse Fourier transformation; filter waveforms in the Fourier domain; filter waveforms according to the peripheral frequency selectivity of the human auditory system; cross-correlate waveforms; autocorrelate waveforms; synthesize complex waveforms, including vowel sounds and white noise. The software can read and write a variety of commonly used waveform file formats. The data can be plotted on an X-Window display using thegnuplot software, which has been included in the package. The complete software package is available via anonymous ftp from ftp.ihr.mrc.ac.uk in ~ftp/pub/johncu/wave.tar.Z     

Independent control of dual video subsystems on the IBM PC and compatibles

Two methods for generating video output on multiple video monitors are described. The first method involves splitting the signal from a single video adaptor card-so that multiple video monitors may be attached. Although this method is simple and relatively cost-effective, it is limited to adaptors that produce only digital video signals, thus precluding the use of VGA systems and composite displays. The second method involves the installation and programming of video adaptors: Two sample programs, which control a secondary adaptor by means of either BIOS routines or direct commands via C code, are described. Although more complex, this second method allows output to each display to be controlled independently. Furthermore, output to one screen may consist of graphics information while output to the second screen consists of text. Together, both methods can be used to create an experimental system composed of multiple data-collection stations and an independent experimenter console.     

ASSESSING OBSERVER ACCURACY IN CONTINUOUS RECORDING OF RATE AND DURATION: THREE ALGORITHMS COMPARED

The three algorithms most frequently selected by behavior‐analytic researchers to compute interobserver agreement with continuous recording were used to assess the accuracy of data recorded from video samples on handheld computers by 12 observers. Rate and duration of responding were recorded for three samples each. Data files were compared with criterion records to determine observer accuracy. Block‐by‐block and exact agreement algorithms were susceptible to inflated agreement and accuracy estimates at lower rates and durations. The exact agreement method appeared to be overly stringent for recording responding at higher rates (23.5 responses per minute) and for higher relative duration (72% of session). Time‐window analysis appeared to inflate accuracy assessment at relatively high but not at low response rate and duration (4.8 responses per minute and 8% of session, respectively).     

The TMS 9918A VDP: A new device for generating moving displays on a microcomputer

A procedure for creating smooth and continuous moving displays on a microcomputer using the TMS 9918A video display processor (VDP) is discussed. This processor shares all of the features of other VDPs and, in addition, enables the user to directly program smooth motion of specified graphics shapes (sprites) with multilevel pattern overlaying. The general principles for programming this video chip are described, and a machine language driver is presented. Three illustrative applications from the event perception literature—wheel-generated motion, kinetic disruption of optical texture, and biomechanical motions—are presented as demonstrations of how the unique features of this video chip can be implemented in the creation of dynamic displays.