Abstract:

People need to be capable of making biologically justified decisions in their everyday life, especially regarding their health, e.g. vaccination, diet or treatment [1]. This emphasises that all people should have at least basic knowledge of biological concepts and they should be able to use their competences to solve everyday problems and make justified decisions. The standards in next generation science standards (NGSS) show what core concepts students should gain in the field of biology by the end of schooling [3].

Students should conceptually understand the core concepts, because it allows development of higher level abilities enabling students to apply their learning ([4], [2]). But there are few studies researching the assessment of students’ conceptual understanding of core concepts in biology.

The aim of this study is to determine the grade 12 students’ achievement profiles of biological conceptual understanding by means of latent profile analysis (LPA) and detect the differentiating core concepts and biology concepts.

Sample of this research consisted of 215 (162 females and 53 males) grade 12 graduates. They undertook the paper-and-pencil test in July 2019. The Biology test consisted of 50 multiple-choice questions, students were given 120 minutes to complete the test.

Three experts evaluated whether items in the test are in accordance with the biology curriculum and with specified learning outcomes. Reliability of the test was detected by the value of Cronbach’s alpha (α=0.986) differentiating that has indicated high internal consistence of test.

Based on the expert opinion and factor analysis the test items were categorised into 4 main groups of main core concepts as follows:
I. From molecules to organisms;
II. Ecosystems;
III. Heredity;
IV. Biological evolution.

Item difficulty index varied from 0.19–0.88. The mean results of items about the 1st core idea varied from 20–88 %. The mean result of items about the 2nd core idea varied from 19–84 The mean result of items about the 3rd core idea varied from 33–65 %. The mean results of items about the 4th core idea varied from 34–58 %. The highest score on the test was 50 points, but no examinee attained this score. The highest score was 42 points and a minimum score was 5 points. The test results followed the normal distribution curve.

LPA is a person-oriented mixture modelling analysis [5], that was used to distinguish students’ profiles based on the achievement levels of the test.

References:
[1] J.M. Bae, “Shared decision making: relevant concepts and facilitating strategies”, 2017, doi: https://doi.org/10.4178/epih.e2017048
M.M. Cooper, A.L. Posey and M.S. Underwood, “Core Ideas and Topics: Building Up or Drilling Down?”, Journal of Chemical Education, vol. 94, pp. 541–548, 2017.
[2] NGSS. (2013). The Next Generation Science Standards. Executive Summary.
[3] K.J. Roth, “Developing meaningful conceptual understanding in science. In B. F. Jones & L. Idol”, Dimensions of thinking and cognitive instruction (pp. 139–175). Hillsdale, NJ, US: Lawrence Erlbaum Associates, Inc, 1990.
[4] G.A. Williams and F. Kibowski, “Latent Class Analysis and Latent Profile Analysis”, In: L. A. Jason, & D. S. Glenwick (Ed.).

Keywords:

Biology education, core concepts, evaluation of competences.