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Various stimulus components (video, orally-presented questions) and response components (multiple-choice, written, orally-given replies) of situational judgement tests of occupational social competency were investigated as to their impact upon the validity for a behavior-oriented role playing criterion while keeping test content constant. The stimulus component video alone had no impact upon validity. The response components contributed to validity. Validity increased with improved fidelity of response components. Concerning stimulus-response-combinations, the validity of two video tests (r = 0.17 and r = 0.36) was not higher than the validity of similar oral questioning (r = 0.13 and r = 0.37) but was significantly lower than a situational interview (r = 0.59). Response fidelity proved to be a bottleneck regarding validity of video tests. As a result, it is recommended that, in order to maximize validity of video and multimedia efforts, the developers of video- and multimedia tests focus special attention on response fidelity.

Serial Digital 4:2:2 Component Video, commonly called Serial D-1, is fast becoming the video format of choice for broadcast and editing professionals. Several problems arise, however, when designing the electronics which support this format, and several special techniques are used to alleviate these problems. This paper provides an overview of Serial D-1 video, the issues which arise when designing and debugging Serial D-1 circuit boards, and how to solve these problems.

Theoretical and experimental evaluation of the objective signal-to-noise performance of component video signals is described. Using a mathematical model, an expression for the component video-signal-to-noise ratio, called the display-signal-to-noise-ratio (DSNR), is derived for Gaussian white noise input. Using this model the signal-to-noise performance of 100% saturated primary and secondary colors are analyzed for a PAL-I video system. In order to verify the theoretical results, an electronic color video circuit was implemented. Using this simulator, objective noise impairments in 100% saturated primary and secondary colors have been determined. >

A description is given of a small-size, light-weight SNG (satellite news gathering) transmission system developed at NHK (Japan Broadcasting Corporation) using digital video-audio bit-reduction technology, which can be used to transmit news from remote gathering spots to the main station (broadcasting station) immediately. The input to the equipment is the component video signal of 4:2:2 conforming to CCIR Rec. 601-1. The composite NTSC signal also may be input. The component video signal is bit-reduced to 7 Mb/s, 11 Mb/s, and 18 Mb/s, respectively, before transmission. The bit-reduction technology used in the system is the adaptive DCT (discrete cosine transformation) using a block-matched motion vector. The system's usefulness has been verified by transmission experiments via satellites. >

A traditional description of the video spectrum and a three-dimensional representation of video that is useful in understanding advanced television (ATV) are provided. Component video systems are described highlighting the desirable characteristics, such as no crosstalk between the components that make up the color signal, which virtually all ATV systems seek to achieve. The three categories of ATV-high-definition television (HDTV), enhanced definition or extended quality television (EDTV/EQTV), and improved definition television (IDTV)-are explained. The basic approaches to ATV and the influence that the FCC (US Federal Communication Commission) has had on shaping the typical systems in theses categories are discussed. Standardization efforts are evaluated. It is concluded that the two delivery systems with long-range potential for highest-quality ATV are fiber-based networks and prerecorded material for home players. The likely time windows for the success of different forms of ATV are predicted, along with speculation about the effect of competition between the three areas of ATV for market share. The general ATV market potential is considered. Video processing is addressed. The importance of display technology for ATV and the need for a CRT replacement are discussed. >

A set of video signal processor VLSIs has been developed using 2-/spl mu/m p-well CMOS technology. These VLSIs perform bidirectional transformation between NTSC (National Television System Committee) composite video signals and component video signals, both of which contain luminance signals and two kinds of color signals. A special circuit configuration is used for the line memory, and an automatic layout program for uniformly structured circuits is developed for the layout design of the digital filters. A design effort of only 12 man-months, which includes logic, circuit, and layout design, is required for each VLSI using CAD systems. These VLSIs have proved effective in reducing the cost of video signal transmission systems.