When people say that what they hear is "over their heads," they are describing a severe information-based complexity (I-BC) problem. They cannot understand what is said because some of the information needed is missing, contaminated, and/or costly to obtain. Students often face these I-BC problems, and teachers often exacerbate them. Yet listeners can provide feedback that will help the speaker give needed information to reduce I-BC problems. However, careful statistical analysis of the feedback is required before speakers can interpret all the data that listeners provide. Causal diagrams, like those used in marketing and social science research, can be used to indicate how "observable" or "hearable" responses from listeners can be used to infer what is wrong and what is right with presentations on difficult topics. (Appended to the document are: (1) seven pages of causal diagrams; (2) a table of definitions; (3) a table of estimation equations; (4) a flow chart of applications of informational theory to speech communication; and (5) two pages of references.) (SKC)