A survey of 138 introductory-astronomy textbooks spanning 152 years reveals growing consensus regarding each topic’s proportion, with some clearly gaining space at the expense of others. The tables in the texts cite curious numbers, claim too many significant digits, neglect to note uncertainties, and are frequently inconsistent with, or badly behind, the research of the times. This study investigates apportionment of topics, planet and star data tables, and categorization of nebulae.

To probe the student/textbook interaction, I used one copy of each of 40 recent introductory textbooks when teaching astronomy in Fall 1986. Students swapped books each session. Texts’ treatments were surveyed in daily recitation as well as term papers comparing and contrasting them on specific topics. Most books sound much more positive than current data justify. There was lots of confusing phrasing, shoddy proofreading, and careless assembly of data tables. A few books are shamefully erroneous. There are numerous impressive examples of the imperfection and transience of “textbook learning.” The biggest and most pervasive sin was writing in the passive voice “Official Style” of interminable sentences laden with prepositional phrases. Illustrations, while important, are secondary to phrasing. Students need and use chapter summaries, glossaries, and indices. About half prefer paperbacks and half hardbacks. Students rated the books for appropriateness to their needs. The experience may stimulate others to develop controlled experiments to probe the student/textbook interaction.