ANALISIS UJI VALIDITAS DAN RELIABILITAS INSTRUMEN TES KEMAMPUAN BERPIKIR KRITS PADA MATERI FLUIDA STATIS

Abstract

Critical thinking skills are one of the skills of the 21st century that need to be 

measured using valid and reliable instruments. Therefore, this study aims to analyze 

the feasibility of critical thinking ability test instruments on Static Fluid materials 

through content validity, empirical validity, and reliability tests. This study uses a 

quantitative approach with a descriptive method. The research subjects consisted 

of three lecturers of Physics Education at Padang State University as validators and 

34 grade XI students of SMAN 6 Padang. The research instrument included expert 

validation sheets as many as 20 statement items and a critical thinking ability test in 

the form of six phenomena-based essay questions developed into 24 questions 

based on Facione's critical thinking indicators, namely interpretation, analysis, 

evaluation, and inference. The validity of the contents was analyzed using the 

Aiken's V index, the validity of the item using Pearson's Product Moment correlation, 

and the reliability using the Cronbach's Alpha coefficient. The results showed that 

the value of Aiken's V ranged from 0.7222–0.8000 so that all aspects of the 

instrument were declared valid. The results of the empirical validity test showed that 

20 out of 24 questions were valid, while 4 were invalid. The reliability test of 20 valid 

questions obtained a Cronbach's Alpha value of 0.912 with a very high category. 

Thus, the test instruments developed meet the criteria of validity and reliability so 

that they are suitable for measuring students' critical thinking skills on Static Fluid 

materials.