RASCH MODEL APPROACH FOR ANALYSIS OF MISCONCEPTION ON CHEMISTRY LEARNING WITH DISTRACTOR ANALYSIS

Multiple-choice questions can be used to identify misconceptions through distractor analysis. Distractor analysis for identifying misconceptions using Rasch modelling to find out how students choose options and whether they have any misconceptions. The test instrument uses questions from the teacher association in Indonesia to assess students’ ability to master chemical contexts. The number of question items used is 35 and has been validated and tested for reliability to be feasible to use. Questions were given to 462 first-year high school students. The fit item analysis results show that there are several questions related to clothing that indicate misconceptions. This is supported by the distractor analysis value, which found that misconceptions indicate questions related to electrolysis, the incidence of colligative properties in daily life and the factors that affect corrosion. The distractor’s value and the option probability curve are used to see how students know the ideas offered. The analysis results found that the material in the form of concepts and their application showed a large misconception, in which students would find it difficult to combine concepts and their applications.


INTRODUCTION
Chemistry studies matter, its properties, how and why substances combine or separate to form other substances, and how substances interact with energy [1][2] in symbols, commonly known as several representations [3].
Chemistry is defined as something abstract due to these three things, which causes a comprehensive understanding of chemistry [4]. Understanding basic chemistry concepts is essential for almost every profession.
Chemistry is a part of everything in our life [5]. This indicates that the item is problematic, or it can also be identified as a misconception [12].
The classical theory of determining misconceptions is based on identification at the individual and question level. To determine the tendency of misconceptions that occur on a large scale, a more precise method is needed [13]. Descriptive analysis, for example, open-ended questions on a small scale and identifying misconceptions at the individual level on a large scale, will certainly be tough [14]. Using the Rasch model will help to analyze misconceptions more precisely and more quickly on a large scale [15]. The Rash model will help identify and analyze more deeply, especially assisted by analyzing the distractors used and the pattern of answers obtained [16].

………… (1)
Bn is the ability of the test taker along with the variables; Di is the difficulty of the test item; Pni is the probability of the test taker correctly answering the certain test items; and 1 -Pni is the probability of one of the test takers answering incorrectly one of the test items [15].
The misconception analysis was obtained from the distractor analysis on multiple-choice questions by looking at the pattern of answers of the participants or the probability items used as a basis for determining the misconceptions that occur.
Besides, the analysis used is to determine the item fit of each item, where the item that exceeds the specified limit is assessed as a matter that has the potential to produce misconceptions. The limits specified are [17]  Outfit of mean square (MNSQ) value obtained: 0.5 < MNSQ < 1.5

RESULTS AND DISCUSSION
The test instrument used was from the chemistry teacher association in Surakarta.
Before we tested the instrument on students,

Value of item fit and item map.
Based on the results obtained from the analysis of the item map on Figure  distractors must be further [11].
Item fit can be used as a way not only to judge whether an item is good or not but also to initially analyze the items that are suspected as misconception items [11] . Item     Students also think that things related to temperature always have a relationship with temperature. The textbook explanations illustrate that the freezing point is something related to salt used to reduce the freezing point of ice [21].
On the one hand, only a few students know ethylene glycol's function car radiators.
Ethylene glycol is used to reduce heat in cars.
In a region with four seasons, the water in the radiator will easily freeze [22]. The radiator with frozen water will certainly affect the performance of the engine. Ethylene glycol serves to reduce the freezing point so that the radiator water will be more difficult to freeze [23].
It is shown in Figure 3 Boiling water has less O2 content than unheated water does because the heat generated will loosen the hydrogen bonds between water molecules, which causes this compound to release some oxygen and some minerals present in the water [24].
Misconceptions occur due to the students' misunderstanding of the basic differences between boiling water and the water that does not experience the healing process. They assume that heating water will make iron rust fast, but they do not realize that the heating effect will reduce oxygen levels in the water to hamper the rusting process. Meanwhile, the acid that slows In the material of oxidation and reduction, the error in assessing that boiling water has a higher oxygen value and acid can accelerate rusting results in the students' misconceptions.