Today’s society faces many challenges related to, among other things, the development of technology, changes in life needs and the environment. These challenges lead to the need to integrate knowledge from many disciplines, as reflected in the concept of STEM education. Developing specific skills to enable evidence-based decision-making in both professional and personal life is also becoming highly important. The skills of obtaining data and drawing conclusions based on it seem to be crucial for the possibility of solving problems related to scientific understanding. Scientific observation is a basic way of obtaining data. The aim of this research was to find out how Czech lower secondary school students are able to observe and classify biological objects. For this purpose, an inquiry-based task following the 5E cycle was used. 70 students from Grade 7 decided whether the fibres presented were animal, plant or synthetic based on observations with a microscope. It was investigated whether the students were able to observe and record the internal structure of the fibres and whether they were able to correctly classify the fibres based on their observations and information about specific characteristics. It was found that the classification success rate of the fibers was 73%. However, there was a statistically significant difference in the correct classification of animal, plant, and synthetic fibers (H = 8.30, p = .016). 73% of students were able to distinguish whether a fibre has a specific structure by observation. However, only 53% of the students correctly noted whether the fibre was internally differentiated into cortex and medulla by observation. Surprisingly, there was no statistically significant correlation between the observation of specific structures and the correctness of the fiber classification (r = .116, p = .093). Thus, it seems that a significant proportion of students follow a rather intuitive approach to classification and do not consider the data they have obtained through their own inquiry in drawing conclusions. The findings point to the need for both the development of scientific observation skills and scientific reasoning involving linking data and results.

Keywords: Scientific skills, scientific observation, obtaining and processing data, lower secondary education, science education.