Graphs These   aids   show   comparisons   between figures.  Four  types  of  graphs  are  illustrated  in figure  7-3.  The  bar  graph  is  one  of  the  most commonly   used.   Graphs   are   useful   when   the information   being   presented   compares   figures from  time  to  time  or  from  several  sources.  For example, a budget meeting may utilize graphs to show  the  increases  and  decreases  of  the  budget over several years. Maps Maps are graphic representations of the sur- face  of  the  earth.  Maps  are  usually  drawn  to scale.  The  type  that  you  are  most  likely  to encounter  is  the  world  map,  used  in  conference rooms,  classrooms,  and  in  briefing  rooms. Illustrations Illustrations are the most versatile of any aid covered  here.  All  aids  make  use  of  illustrations to  some  degree  in  their  planning  stages,  and perhaps  even  in  their  final  form.  Charts,  car- toons, maps, and signs are illustrations that are often used to present or clarify an idea. Photographs Photographs  may  be  passed  from  hand  to hand  or  posted  on  a  board  in  front  of  an audience.  They  can  be  used  most  effectively  in small  groups.  Photographs  are  extensively  used for  documentation  purposes. Brochures and Handouts Brochures  are  small  pamphlets  composed  of illustrations  and  printed  material,  but  they  are generally   much   briefer   than   handouts.   When given to students or an audience, these materials should help the people understand the presenta- tion.  Handouts  are  normally  retained  by  the audience   for   purposes   of   reference   and   later review. used to tion. Long after the presentation, they can be review important points of the presenta- PROJECTED AIDS Projected   aids   are   those   that   require audiovisual  equipment  in  order  to  be  presented properly.  Some  of  the  aids  included  in  this category   are   slides,   filmstrips,   overhead transparencies (vu-graphs), and motion pictures. It  is  important  to  remember  that  most  nonpro- jected  aids  may  be  adapted  for  use  as  projected aids. A chart, for example, can be photographed and made into a slide. Slides  and  Filmstrips Anything  that  can  be  photographed  can  be made  into  a  slide.  Slides  are  one  of  the  best known   projected   aids.   They   are   found   in   all types  and  levels  of  briefings,  both  informative and  educational.  Presentations  utilizing  35-mm slides  can  be  both  informative  and  educational, while  at  the  same  time  they  can  be  relatively inexpensive  to  produce.  Filmstrips  are  used primarily  in  an  educational  environment.  Each frame of the 35-mm filmstrip is related to others in such a way that an entire story or lesson can be contained in one strip. A major disadvantage of  filmstrips  is  that  they  cannot  be  repaired (spliced)  without mation. Transparencies losing  a  portion  of  their  infor- As  used  here,  transparencies  refer  to  large vu-graph   transparencies   projected   with overhead  projectors.  Depending  on  time  factors, the information to be presented, and the quality of  transparency  desired,  production  methods may  vary  from  typed  information  on  clear plastic  to  complex  illustrations  on  colored film.  The  standard  size  is  7-1/2  x  9  inches (19 x 23 cm). Motion Pictures Motion  pictures  have  received  extensive  use in  training  and  information  programs.  Until recently,  16-mm  motion  pictures  were  the primary visual aid in many programs. However, 16-mm  films  are  expensive  to  produce,  often more  general  in  nature  than  is  required  by  the course   curricula, and   they   often   become 7-6