Curriculum development is not carried out in isolation but is part of the planning, development, implementation, and review cycle. It can describe development at different levels: large-scale curricular reform to changes to individual lessons. There are various models that can be adapted to form the basis of curriculum development.

Linear product or objectives model. First developed by Tyler (1949:  Veness 2010) and later modified by Taba (1965:  Veness 2010). This model proposes that all learning is defined in terms of what learners should be able to do at the end of the course. Its focus is on learning outcomes and uses a systematic approach to planning. It starts with the outcomes of the course and then from there the course content is developed to enable the achievement of stated outcomes, which are then evaluated for their effectiveness of achieving the stated outcomes. The focus is on teaching.

There are 4 steps to curriculum design

·         Identify the broad aims and specific objectives

·         Construct the course so objectives can be achieved

·         test capacity of the course to achieve objectives

·         explain the curriculum and objectives to teachers

Tyler’s Model

Tyler’s model for curriculum designing is based on the following questions:

• What educational purposes should the school seek to attain?
• What educational experiences can be provided that is likely to attain these purposes?
• How can these educational experiences be effectively organized?
• How can we determine whether these purposes are being attained?

Tyler’s Model by diagram

                          The model is linear in nature, starting from objectives and ending with evaluation. In this model, evaluation is terminal. It is important to note that:

• Objectives form the basis for the selection and organization of learning experiences.
• Objectives form the basis for assessing the curriculum.
• Objectives are derived from the learner, contemporary life and subject specialist.

To Tyler, evaluation is a process by which one matches the initial expectation with the outcomes.

Taba’s Model

Taba’s model based upon the curriculum development process similar to Tyler's, but introduced additional steps and called for more information to be provided for each of them. The model is:

Wheeler’s Model

Wheeler’s model for curriculum design is an improvement upon Tyler’s model. Instead of a linear model, Wheeler developed a cyclical model. Evaluation in Wheeler’s model is not terminal. Findings from the evaluation are fed back into the objectives and the goals, which influence other stages.

                                                  Wheeler contends that:

• Aims should be discussed as behaviours referring to the end product of learning which yields the ultimate goals. One can think of these ultimate goals as outcomes.
• Aims are formulated from the general to the specific in curriculum planning. This results in the formulation of objectives at both an enabling and a terminal level.
• Content is distinguished from the learning experiences which determine that content.

Hilda Taba is a curriculum theorist, a curriculum reformer, and a teacher educator. She had a strong belief that students could be taught to think — specifically to analyze information and create concepts. She believed that students make generalizations only after data are organized.  She believed that students can be led toward making generalizations through concept development and concept attainment strategies. According to Taba, the best way to deal with increase in knowledge is to emphasize the "acquisition, understanding, and use of ideas and concepts rather than facts alone."

Turner and Fattu were initially interested to develop a diagnostic test for teachers to identify the learning difficulties which students had to encounter. The mastery over the subject matter is essential for teachers to diagnose the students learning difficulties. It is an assumption of this model. This model of teaching utilizes stimulated teaching to develop problem-solving skills. The learning difficulties are diagnosed and suggestions are given for improvement. This model is more useful for teachers rather than classroom teaching.

The following are the comparisons Tanners model and Taba's mode by using a table according to (Sigalla, 2003).

TANNER'S MODEL                                                 TABA’S MODEL

1(C)

The following are the reasons as to why does wheelers model seem to have the same shortcomings as Tabas model;

I). There is still a one to one relations between the elements, if he would make them relate and affect every other element in the model by removing numbers he could differ from Taba's model

ii). The numbering by wheeler from 1-5 seems to suggest that the curriculum always starts with objectives and ends with an evaluation.

iii). There is no connection between objective and evaluation although it has seven steps