The rise of the structured programming movement led to many other "structured" approaches applied to software design. The techniques of structured analysis and structured design are outgrowths of structured programming concepts and techniques, and of the early ideas about modular design. Principles of modularity were strengthened by Larry Constantine's concepts of coupling (to be minimized between modules) and cohesion (to be maximized within modules), by David Parnas's techniques of information hiding, and by abstract data types. A number of tools and methods employing structured concepts were developed, such as Structured Design, Jackson's Structured Programming, Ross' Structured Analysis and Design Technique (SADT), Yourdon's Structured Method, Structured Systems Analysis and Design Method (SSADM), and James Martin's information technology engineering. The field of software metrics is often considered as a direct influence of the structured programming movement on software engineering in the 1970s.