4. Discussion and Conclusion
The effectiveness of the sample lesson plan that was developed by the researchers on 8th grade students’
achievement levels in terms of gaining the objectives in a secondary school science course was investigated in this
study. This is a pilot study, which is applied to the small group of students before the main implementation. It is
found that students had inadequate knowledge about acids and bases before the study but they managed to gain the
learning outcomes in sufficient level after the implementation. However, it is thought that students’ mean score on
achievement tests (x=23.25, SD=2.89) can be increased by using additional activities on the disciplines of STEM
approach, seeing that the highest score of achievement test is 30. One of the reasons might be insufficient
engineering activities in this study. Additional engineering activities should be applied using project based
instructions with more interested students. Lantz (2009) stated that the engineering element of STEM education
helps students explore mathematics and science in a more independent way, while helping them to develop the
critical thinking skills that can be applied to all facets of their work and academic lives. Engineering is a method that
students utilize for discovery, exploration, and problem solving.
One of the goals of STEM education is to raise interdisciplinary thinkers (Figliano, 2007). Four disciplines of
STEM education combined to teach a science subject were used in the study. The results of this study are consistent
with the study conducted by Becker and Park (2011). Their study showed that students’ achievement on the
integrated concepts of STEM literacy showed large effect sizes. Science achievement presented a medium effect
size while the technology achievement showed a large one. Also, Aurandt (2012) found that STEM education has
been effective on learning and accomplishment of learning objectives. Raines (2012) remarked that student