Exploring Item Validity: Critical-Science Process Skills Integrated Assessment Instrument on Electrolyte Solution and Acid Base Matter

Abstract

The demanding of assessment in learning process was affected by policy changes. Students should be prepared to address the challenges with higher level skills involving critical thinking and science process skills, so that they can solve problems in educational learning and other fields. Recognizing the importance of the development of critical thinking and science process skills, the instrument should give attention to the characteristics of chemistry. Therefore, constructing an accurate instrument for measuring those skills is important. However, the integrated instrument assessment is limited in number. This paper aimed how to develop integrated assessment instrument and to verify instrument's validity such as content validity and construct validity on electrolyte solution and acid base matter.  The model development of the test instrument adapted McIntire mode. Process data development was acquired based on the development test step and was analyzed by qualitative analysis. To acquire content validity, initial product was observed by six peer reviewers of postgraduate students and 14 experts including ten teachers and four lecturers. This research involved 376 students of grade X from two senior high schools in Bantul Regency and 392 students of grade XI from three senior high schools in capital city of Yogyakarta to acquire construct validity. Exploratory factor analysis (EFA) was conducted to explore construct validity, whereas content validity was substantiated by Aiken's formula. The results showed that all items in integrated assessment instrument are asserted valid according to content validity and construct validity. Therefore, the integrated assessment instrument is suitable for measuring critical thinking abilities and science process skills of senior high school students on electrolyte solution and acid base matter.