[In Let X Be Excitement, which is based on the life of her son, Harris] has created a new, commendable addition to her collection of family portraits. For Ralph, discovering his life's occupation meant finding a job that offered intellectual challenge and satisfied his love of excitement and the outdoors…. Ralph's satisfaction in doing what comes naturally, combined with a sense of humor, results in an appealing zest for living. Readers (boys particularly) facing career decisions will empathize with Ralph, and enjoy, even though they may not be able to equal, his adventures. (p. 124)

Julie Losinski, in School Library Journal (reprinted from the September, 1969 issue of School Library Journal, published by R. R. Bowker Co. A Xerox Corporation; copyright © 1969), September, 1969.