studies of the direct instruction program have shown that it is
Direct instruction One three-year study of methods of teaching reading showed that highly scripted, teacher-directed methods of teaching reading were not as effective as traditional methods that allowed a more flexible approach.[12] Urban teachers in particular expressed great concern over the DI's lack of sensitivity to issues of poverty, culture, and race.[12]
Ladder logic Ladder logic has evolved into a programming language that represents a program by a graphical diagram based on the circuit diagrams of relay logic hardware. Ladder logic is used to develop software for programmable logic controllers (PLCs) used in industrial control applications. The name is based on the observation that programs in this language resemble ladders, with two vertical rails and a series of horizontal rungs between them. While ladder diagrams were once the only available notation for recording programmable controller programs, today other forms are standardized in IEC 61131-3 (For example, as an alternative to the graphical ladder logic form, there is also a more assembly language like format called Instruction list within the IEC 61131-3 standard.).