Experimental studies conducted since 1980 were reviewed. Each of the 34 studies concerning problem solving is briefly summarized, followed by comments, criticisms, and/or concerns. A summary indicates that experimental research of the 1980s seems to focus on: (1) children's processes, understanding, functioning, difficulties, and representations; (2) instructional models and techniques; and (3) the language, readability, structure, format, and syntax of problems. Omissions of topics, general findings, and criticisms are noted. Then 34 "major findings" are listed, followed by 55 suggestions and questions for further research. Forty-two references are provided, and an appendix presents three general semantic categories for addition and subtraction word problems. (MNS)