1. A system for measuring reactions to packaging, advertising, and product configuration at computer systems over a network, said system comprising: at least one first computer system connected to said network; at least one second computer system capable of connecting to said first computer system through said network in which said first computer system has a browser for viewing pages from said second computer system; said second computer sending to said first computer a set of questions to be displayed by the browser on one or more pages having one or more images downloaded from said second computer system for stored by the browser in memory of said first computer system which are displayed into pixel areas on display of the respondent's computer system which avoids user detection of the downloaded images, and said second computer system receives answers from said questions from said first computer system; and said second computer instructs the browser of said first computer to display at least one of said images previously displayed in said pixel areas from the memory of the first computer system for a short interval of time, and to display at least one question regarding said image displayed for said short interval of time, and said second computer system receives the answer from said question from said first computer system.