Valid measurement scales for predicting user acceptance of computers are in short supply. Most subjective measures used in practice are unvalidated, and their relationship to system usage is unknown. The present research develops and validates new scales for two specific variables, perceived usefulness and perceived ease of use, which are hypothesized to be fundamental determinants of user acceptance. Definitions of these two variables were used to develop scale items that were pretested for content validity and then tested for reliability and construct validity in two studies involving a total of 152 users and four application programs. The measures were refined and streamlined, resulting in two six-item scales with reliabilities of .98 for usefulness and .94 for ease of use. The scales exhibited hgih convergent, discriminant, and factorial validity. Perceived usefulness was significnatly correlated with both self-reported current usage r = .63, Study 1) and self-predicted future usage r = .85, Study 2). Perceived ease of use was also significantly correlated with current usage r = .45, Study 1) and future usage r = .59, Study 2). In both studies, usefulness had a signficnatly greater correaltion with usage behavior than did ease of use. Regression analyses suggest that perceived ease of use may actually be a causal antecdent to perceived usefulness, as opposed to a parallel, direct determinant of system usage. Implications are drawn for future research on user acceptance.

Perceived usefulness, perceived ease of use, and user acceptance of information technology

This paper presents a theoretical model of situation awareness based on its role in dynamic human decision making in a variety of domains. Situation awareness is presented as a predominant concern in system operation, based on a descriptive view of decision making. The relationship between situation awareness and numerous individual and environmental factors is explored. Among these factors, attention and working memory are presented as critical factors limiting operators from acquiring and interpreting information from the environment to form situation awareness, and mental models and goal-directed behavior are hypothesized as important mechanisms for overcoming these limits. The impact of design features, workload, stress, system complexity, and automation on operator situation awareness is addressed, and a taxonomy of errors in situation awareness is introduced, based on the model presented. The model is used to generate design implications for enhancing operator situation awareness and future directio...

Toward a Theory of Situation Awareness in Dynamic Systems

The authors address the role of marketing in hypermedia computer-mediated environments (CMEs). Their approach considers hypermedia CMEs to be large-scale (i.e., national or global) networked enviro...

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Marketing in Hypermedia Computer-Mediated Environments: Conceptual Foundations

Undergraduates expressed their attitudes about a product after being exposed to a magazine ad under conditions of either high or low product involvement. The ad contained either strong or weak arguments for the product and featured either prominent sports celebrities or average citizens as endorsers. The manipulation of argument quality had a greater impact on attitudes under high than low involvement, but the manipulation of product endorser had a greater impact under low than high involvement. These results are consistent with the view that there are two relatively distinct routes to persuasion.

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Central and Peripheral Routes to Advertising Effectiveness: The Moderating Role of Involvement

The purpose of this article is to review basic empirical results from the psychological literature in a way that provides a useful foundation for research on consumer knowledge. A conceptual organization for this diverse literature is provided by two fundamental distinctions. First, consumer expertise is distinguished from product-related experience. Second, five distinct aspects, or dimensions, of expertise are identified: cognitive effort, cognitive structure, analysis, elaboration, and memory. Improvements in the first two dimensions are shown to have general beneficial effects on the latter three. Analysis, elaboration, and memory are shown to have more specific interrelationships. The empirical findings related to each dimension are reviewed and, on the basis of those findings, specific research hypotheses about the effects of expertise on consumer behavior are suggested.

Dimensions of Consumer Expertise

Absfracf-The impact of gate leakage current on MOSFET performance has been examined and limits on gate oxide thickness for static and dynamic logic have been determined. Leakage current has been found to he a greater problem for static logic than dynamic logic circuits. Gate leakage current limits the minimum oxide thickness to approximately 2 nm for static logic configurations and to approximately 3 nm in dynamic logic circuits. A poor drain design can become a limiting factor for dynamic logic circuits and raise the minimum oxide thickness required. Switching delay of static logic is relatively immune to the effects of leakage current. A MISFET with a 2.6 nm thick gate insulator of Si3N, has been fabricated showing typical drain current characteristics, but with a large amount of gate leakage current.

Thickness Limitations of Si02 Gate Dielectrics for

For original paper see ibid., vol.10, p.141-3 (Apr. 1989). The commenters point out that the authors of the original paper were not, as they have claimed, the first to show the technique and benefits of implanting and diffusing fluorine. They raise a number of questions about their experimental method and interpretation of results. The authors reply that they did not make the claim attributed to them, and they defined their method and findings at length. >

Comment, with reply, on 'Hot-electron hardened Si-gate MOSFET utilizing F implantation' by Y. Nishioka, et al

Results are reported on n-channel insulated-gate field effect transistors (IGFETs) with gate insulators (50-60 AA) formed by rapid thermal processing (RTP) in O/sub 2/ and NH/sub 3/ ambients. Two types of gate dielectrics were grown: rapid thermal oxides grown in O/sub 2/ and nitroxides formed by multicycle processing in NH/sub 3/ and O/sub 2/. RTP was also used for annealing AS/sup +/-implanted source-drain junctions at 1050 degrees C for 30 s. The transistors were characterized by measuring mu /sub eff/, V/sub T/, subthreshold slope, Q/sub f/, D/sub if/, D/sub bd/, and hot-electron immunity. The observed trends are discussed. The results demonstrate excellent device characteristics, including, in particular, increased hot-electron immunity and resistance against high-energy electron irradiation. >

Electrical characteristics and irradiation sensitivity of IGFETs with rapidly grown ultrathin gate dielectrics

A new technique of post-oxidation annealing has been introduced to improve the properties and long term reliability of ultrathin (<100 A) MOS gate dielectrics. In this technique, after oxidation, nitridation is done in NH3 followed by a light reoxidation in O2 and then an inert anneal in Ar or N2. Using this technique both optimum performance as well as reliability can be obtained without sacrificing either. NH3 anneal of SiO2 improved the hot electron immunity, but degraded the interface quality. Good properties could be obtained by a strong reoxidation of the nitrided films, however, at the expense of a substantial increase in the film thickness. Nitrogen and argon ambients were found to be equally effective at improving film properties. By annealing the film in an inert ambient following reoxidation of the nitroxide, fixed charge can be further decreased with little oxide grown, electron mobility in NMOS FETs increases further, and the hot electron lifetime is much longer than that of the starting oxide.

Peter Wright

Papers

Thickness Limitations of Si02 Gate Dielectrics for

Comment, with reply, on 'Hot-electron hardened Si-gate MOSFET utilizing F implantation' by Y. Nishioka, et al

Electrical characteristics and irradiation sensitivity of IGFETs with rapidly grown ultrathin gate dielectrics

The Effect of Post-Growth Anneals on Nitroxide Films

IIIB-1 submicrometer IGFET fabrication by rapid thermal processing