Instruction is a plan of teaching & learning activities in which learning is organized.  This instructional plan motivates students to learn.  The aim of instruction is to make the learning process take place.  According to Gustafson (1996), instructional design is: 

1.  analyzing what is to be taught/learned;

2.  determining how it is to be taught/learned;

3.  conducting tryout and revision; and

4.  assessing whether learners do learn. 

In the instructional design process, there are a lot of factors that should be taken into consideration.  These factors are closely related to each other and affect each other to a certain extent.  These factors should be organized in the instructional design steps.  For example, if the goals and objectives are not chosen, specified or written properly, then the next and other steps will contain some problems because of the inappropriate and incomplete items in the previous step.  In the instructional design, the steps are all interrelated with each other.  It is very important to order the steps in a way that will be logical and in relation with other steps.  In other words, instructional design is a big responsibility to design teaching and learning activities.  All steps should be thought and chosen carefully and should be ordered in a meaningful way.  Every detail can play an important role during the implementation.  Every decision should be given due to a reason, not just for the sake of doing so.  The designer should be fully aware of the relationship among the steps.  During the teaching and learning process, the designer should collect reliable data about the students, their backgrounds and their prerequisite learning.  Due to the reason that they play an important role on the outcomes of instruction, they should seriously taken into consideration and help designer to create a model that will help them to keep a balance between them.  An instructional design model gives method and implication to design instruction.  During the instructional design process, I.D. models help educators to visualize the problem.  If the instructional design model solves the learning-teaching problems, it means that it is an effective instruction.