This study aimed to develop a two-tiers diagnostic test to assess the high school, junior high school, and elementary pre-service teachers about the heat and the temperature concepts in a general physics course. There are two tiers in this test: The first tier composed of six items consisting of multiple-choice questions related to the heat and the temperature, including the correct answer. The second tier of each item contains reasons for students choosing their answer to the first tier. The second tier included four or five responses, one of which is a correct conceptual understanding. The wrong answers, also called distractors, were based on students’ misconceptions. To this end, 128 pre-service teachers from Quebec in Canada completed a pencil-paper questionnaire of sixty minutes duration composing of six questions (four open-ended questions and two multiple choice questions with justifications). As illustrations, the following  conceptual understandings have been identified in our qualitative analysis of the data collected: 1. The change of state of the matter does not require a constant temperature; 2.  The temperature is a measure in degrees to indicate the level of heat of an object or person; 3. The mercury contained in a thermometer expands when it is heated so that the particles which constitute it expand; and 4. The sensation of cold (or warm) is related to the difference in temperature.

This study examines the validity of the Force Concept Inventory (FCI) in Ugandan secondary schools using Item Response Curves (IRCs) and provides a comparative evaluation of its effectiveness across different educational contexts. The survey focused on Senior Four students preparing for the Uganda Certificate of Education (UCE) examinations, with a representative sample of 941 students (aged 15–17) selected through a multi-stage sampling technique. The initial analysis employed Classical Test Theory (CTT) metrics before the detailed analysis of IRCs for the FCI items. The CTT evaluates item-level and whole test statistics like item difficulty level, discrimination index, and reliability. The CTT indices revealed that the FCI was highly challenging, with an average score of 5.76 out of 30 and a low-reliability coefficient (α = 0.15). Additionally, 73.3% of the items showed poor discrimination, and some distractors were ineffective. The detailed analysis of IRCs showed that several FCI items are inefficient in the context of the Ugandan education system. The IRCs also demonstrated a widespread choice of distractors for many items, with overall scores falling below the threshold indicative of a generally agreed-upon understanding of Newtonian physics. Comparative analysis from other global contexts studies suggests that language barriers, curriculum differences, and instructional methods influence student performance. These findings underscore the necessity of adapting the FCI tool to better fit local educational contexts and implementing additional instructional strategies to enhance conceptual understanding. A more culturally and contextually adapted diagnostic tool may improve physics education and better assess students’ conceptual comprehension of force and motion within the region.