An instructional design model to teach nature of science

For adapting the model, the literature review on the explicit-reflective-embedded approach, and other approaches used in NOS teaching, was conducted first. Then, the framework of an instructional design model was determined by investigating the related literature. The important components of these varied approaches to teaching NOS were incorporated into the framework. Next, the model was personally validated by asking science education experts about utility, adaptability, feasibility and understandability of the components of the model (Wedman & Tesmer, 1993; Dick, Carey & Carey, 2005). Finally, a four-round Delphi Study approach with a panel of six experts was utilized to provide evidence of internal validity of the model. The characteristics of the experts are presented in Table 1.

Expert Code	Posession of Master or PhD Degree	Department	Research Interest	Experience on Education (Year)
E1	PhD	Science Education	Instructional strategies, measurement and evaluation	14
E2	PhD	Secondary Science and Mathematics Education	Instructional strategies, technology supported education	8
E3	PhD	Program Development and Instruction	Self-regulation and goal setting	7
E4	MEd	Elementary Teacher Education	Scientific Literacy	3
E5	MEd	Computer Technologies and Instruction	ARCS model, motivation	3
E6	MEd	Elementary Teacher Education	Program development, material design and instruction	5

Table 1. The basic characteristics of the experts

In the first round, the proposed model was introduced to the experts with its theoretical foundations. Then, the application of the open-ended questionnaire about the different aspects of the model was discussed in the second round. The questionnaire items were related to utility, adaptability, feasibility and understandability. The items were designed to provide negative and positive opinions on the model. Therefore, each item included two sub-items. For example, one question asked, “Could you evaluate the model in terms of utility?”. The following sub-questions were, “Could you provide negative aspects of the model in terms of utility?” and “Could you provide positive aspects of the model in terms of utility?”. After this analysis, the experts were asked, “What is the best important characteristic of the model for you?”. Finally, the revised model was presented to the experts to provide consensus.