In this study, simple randomization method is used to assign male elementary school students in Izeh to two experimental and control groups. The randomization unit in this study is male elementary school students who are eligible to enter the study. First, a complete list of volunteer students who have been selected based on the study entry criteria is prepared. Then, each student is assigned a unique numerical identification code. These codes are entered into the Random Number Generator software and a random number is generated for each student. After generating these numbers, the students are sorted in ascending order based on the value of the random number. Then, the individuals are assigned to two groups; sequentially, the first 15 on the list are assigned to the experimental group and the next 15 to the control group. With this method, the order in which the students enter the study and the researcher knows them will not play any role in determining the group. To conceal allocation, the person responsible for entering data and performing the randomization process in the software will be independent of the interactive educational game intervention administrators and the research evaluators and will not have access to information about the implementation of the intervention or changes in student allocation. Also, student identification codes will be kept confidential and separate from their other personal information. Therefore, it will not be possible to predict the assigned group for each student before the randomization process.
In order to control bias and improve the internal validity of the study, this study was designed as a blinded evaluator and blinded analyst; in this way, the outcome evaluator and data analyst will be kept unaware of the allocation of male elementary school students to the experimental and control groups. Given the nature of the intervention, namely the implementation of an interactive educational game, blinding the students and the intervention administrator is not possible; because the students in the experimental group directly participate in the educational game activities. In this process, the outcome evaluator will collect and record data related to mathematical concept understanding, mathematical problem solving, and overt anxiety at all stages of the pretest, posttest, and possible follow-up, without knowing the students' assigned group, in order to reduce the possibility of bias in measuring and recording the results. Also, all questionnaires and assessment forms with anonymous codes, such as “Group 1” and “Group 2,” will be provided to the statistical analyst, and the true nature of the groups will not be revealed until the statistical analyses are completed. All steps of randomization and assignment of students to experimental and control groups will be performed by an individual independent of the educational game facilitator and the research evaluators. Decoding of assignment codes will also be done only after the final completion of the statistical analyses. In this way, the possibility of the evaluator and analyst’s knowledge of the students’ groupings affecting the research results is minimized.