  With the increasing importance of Computational Thinking (CT) at all levels
of education, it is essential to have valid and reliable assessments.
Currently, there is a lack of such assessments in upper primary school. That is
why we present the development and validation of the competent CT test (cCTt),
an unplugged CT test targeting 7-9 year-old students. In the first phase, 37
experts evaluated the validity of the cCTt through a survey and focus group. In
the second phase, the test was administered to 1519 students. We employed
Classical Test Theory, Item Response Theory, and Confirmatory Factor Analysis
to assess the instruments' psychometric properties. The expert evaluation
indicates that the cCTt shows good face, construct, and content validity.
Furthermore, the psychometric analysis of the student data demonstrates
adequate reliability, difficulty, and discriminability for the target age
groups. Finally, shortened variants of the test are established through
Confirmatory Factor Analysis. To conclude, the proposed cCTt is a valid and
reliable instrument, for use by researchers and educators alike, which expands
the portfolio of validated CT assessments across compulsory education. Future
assessments looking at capturing CT in a more exhaustive manner might consider
combining the cCTt with other forms of assessments.
