_Large Photos._ Unless your photographs can be viewed in detail without stooping and squinting, either have them enlarged or discard them. _Color Photos._ Color photos are expensive, but just one or two will add interest to a large group of black-and-white prints. _Charts and Graphs._ If your exhibit contains charts and graphs, keep them simple. Avoid line charts if several curves must cross and recross. Logarithmic charts, scatter diagrams, and similar ratio charts are confusing to the average viewer. Caption and explain charts and graphs adequately. Simple pie, bar, and representational charts, as shown in Figure 6, can be particularly meaningful. Often the use of colors will make the various factors more discernible. [Illustration: Figure 5] _White Space._ Next to content, the exhibitor’s most valuable tool is “white space”—those unoccupied areas of his display panels. Crowded, busy panels on which materials and text fill every inch of space are a hallmark of the amateur. Worse, they defeat their purpose, for viewers usually take one hurried glance, decide that understanding so cluttered an exhibit would be a chore, and move on to simpler displays. (As a rule of thumb, approximately 40% of your available display space should be occupied by absolutely nothing!) _Organization._ Just as you organize words into sentences and paragraphs, your exhibit elements (textual and visual) should be organized into groups and subgroups. (See Figures 1 and 2.) Here again the “feature” technique may be employed. For example, if you are displaying several similar specimens you may emphasize the most unusual one by placing it on a raised or differently-colored background as shown in Figure 7. [Illustration: Figure 6] [Illustration: Figure 7] _Apparatus._ Amateur exhibitors sometimes get carried away with enthusiasm for large arrays of mechanical apparatus which are both unnecessary and confusing. If your project involved development of a unique piece of equipment, consider whether you can display it alone, without the entire assembly into which it fits. Sometimes this can be done by displaying the featured part alongside a drawing or photograph of the complete assembly, as in Figure 4. Again, keep details to a minimum; leave them in the project report. _Mechanical movement._ Usually motion in a science fair exhibit is called for only when there is a clear need for it. Thus it is logical to use a turntable to revolve different fluorescing mineral specimens under “black light”, or to present successive radioactive ore specimens to a Geiger-counter probe. But to use such a turntable to present a series of photographs would probably be unnecessarily contrived. Usually you may spend your efforts better on sound content, clean design, and clear text than on mechanical gimmicks.