**5. Development of four-tier instrument in the topic of electrolyte and non-electrolyte solution (FTI-ENES): an empirical study**

This section will present our current study in this area involving the development of a four-tier instrument in the topic of electrolyte and non-electrolyte solution. The instrument that was produced in this study is named the Four-Tier Instrument of Electrolyte and Non-Electrolyte Solution (FTI-ENES).

## **5.1 Method**

This research employed the procedure proposed by Habiddin & Page [7] with six steps, as explained in Section 3 above. In the first step (mapping concept), it was found that differentiating electrolyte solution and non-electrolyte solution based on its electrical conductivity is the essential concept for a secondary school in Indonesia. The essential concept covers three indicators of competencies, including [1] identifying the electrical conductivity of the solution of an ionic compound, [2] identifying the electrical conductivity of the solution of covalent compound, [3] identifying the electrical conductivity of the solution of the polar covalent compound.

Next, several 22 MCQ-FR questions were constructed and intended to measure students' unscientific understanding regarding the three indicators. The example of a question in the MCQ-FR is presented in **Figure 9**. The questions were assessed in term of the scope of chemistry content and clarity in the language before being used for data collection by the chemistry lecturer and school teacher. The suggestions and feedbacks obtained were the basis for improving or revising the MCQ-FR.

In this study, the questions were focused on the conceptual type of question and avoided the algorithmic type. The initial data collection was carried out and involved five groups of students (153 in total) from two public secondary schools in Malang, East Java, Indonesia. Two groups from SMA Negeri 3 Malang (Public secondary school 3 in Malang) and three groups from SMA Negeri 8 Malang (Public secondary school 8) had taken the subject of electrolyte and non-electrolyte solutions.

Students' responses to the MCQ-FR of electrolyte and non-electrolyte solutions were categorized into scientific responses, unscientific responses and random responses. The unscientific responses were the basis to produce the FTI-ENES with 13 questions that experienced content validity afterwards. Next, the FTI-ENES was validated empirically involving two groups of students (62 in total) from SMAN 2 Ponorogo, East Java, Indonesia (Public secondary school 2 in Ponorogo). The parameters used in the empirical validation, including reliability, validity, difficulty level, discriminatory index and distractor effectiveness. Based on these parameters' values, improvements/revisions were made to refine the FTI-ENES and produce the final version of FTI-ENES.

#### **Figure 9.**

*Example of a four-tier instrument in electrolyte and non-electrolyte solution.*
