BESSER also addressed problems in platform design, namely, deciding how large a machine to design for situations when the largest number of users have the lowest level of the machine, and one desires higher functionality. BESSER then proceeded to the question of file size and its implications for networking. He discussed still images in the main. For example, a digital color image that fills the screen of a standard mega-pel workstation (Sun or Next) will require one megabyte of storage for an eight-bit image or three megabytes of storage for a true color or twenty-four-bit image. Lossless compression algorithms (that is, computational procedures in which no data is lost in the process of compressing [and decompressing] an image--the exact bit-representation is maintained) might bring storage down to a third of a megabyte per image, but not much further than that. The question of size makes it difficult to fit an appropriately sized set of these images on a single disk or to transmit them quickly enough on a network. With these full screen mega-pel images that constitute a third of a megabyte, one gets 1,000-3,000 full-screen images on a one-gigabyte disk; a standard CD-ROM represents approximately 60 percent of that. Storing images the size of a PC screen (just 8 bit color) increases storage capacity to 4,000-12,000 images per gigabyte; 60 percent of that gives one the size of a CD-ROM, which in turn creates a major problem. One cannot have full-screen, full-color images with lossless compression; one must compress them or use a lower resolution. For megabyte-size images, anything slower than a T-1 speed is impractical. For example, on a fifty-six-kilobaud line, it takes three minutes to transfer a one-megabyte file, if it is not compressed; and this speed assumes ideal circumstances (no other user contending for network bandwidth). Thus, questions of disk access, remote display, and current telephone connection speed make transmission of megabyte-size images impractical. BESSER then discussed ways to deal with these large images, for example, compression and decompression at the user's end. In this connection, the issues of how much one is willing to lose in the compression process and what image quality one needs in the first place are unknown. But what is known is that compression entails some loss of data. BESSER urged that more studies be conducted on image quality in different situations, for example, what kind of images are needed for what kind of disciplines, and what kind of image quality is needed for a browsing tool, an intermediate viewing tool, and archiving.