Mental retardation is an intellectual disability characterized by intelligence being below average. People who are mentally retarded can learn new abilities, but the pace of learning is very slow. There are problems that often occur in the detection that children have mental retardation, especially by parents due to the lack of knowledge of the parents about this, resulting in the mistake of choosing the right type of learning for children. If this is allowed to continue, it will result in the child's mental condition getting worse. Due to these problems, a solution is offered in the form of an expert system application with the Case Based Reasoning (CBR) method, this method will match the symptom data of the old disease with the symptom data consulted by the user so that the similarity number of each type of mental retardation will be produced. The final result of this study is the percentage value of similarity along with recommendations in the form of suggestions and solutions that will be carried out by parents in providing independent education to children with mental retardation. The results obtained were in the form of mental retardation with a percentage of 0%, disabled with a percentage of 82.35%, with disabilities with a percentage of 0%.

Today, information technology, especially soft computing technology is growing rapidly. One of the soft computing technologies that has been widely developed is fuzzy logic. This is because it can be used to measure various phenomena that are unclear, obscured or obscured. One of the research themes that uses fuzzy logic is the assessment system in research. Research [Graha Nusantara Padangsidimpuan Data Simlitabmas Still in the Leadership category for promotion to the Madya Faculty of UGN Padangsidimpuan is challenged to develop, dedicate and apply the knowledge needed in research. The goal according to this research is to apply fuzzy reasoning with the Mamdani method for lecturer research activities at the University of Graha Nusantara Padangsidimpuan. This research uses Mamdani fuzzy logic. The Mamdani fuzzy method is a way to convert the input space to the output space.

Children at the age of 1 year (toddlers) are more susceptible to the disease, parents must always give more attention to their children with poor health conditions, of course it will be very important for the growth of children. Application of an expert system to diagnose digestive diseases by using the forward chaining method can help parents in knowing the state of children's health. This research is an applied technology product that can provide benefits as a media or instructor in handling patients. The design of this system has been carried out through data activities, rule design, process design and system testing. From data and information found handling facts. The results obtained from system testing using the PHP MySQl application indicate that the results of diagnoses and pediatric diseases at Tanjung Balai General Hospital, have as many as 10 patient data that have been examined by experts and have conducted system checks to achieve 80% accuracy, from the conclusions that can be concluded data obtained from experts developed using the Forward Chaining Method are appropriate in determining the symptoms and diseases obtained from experts.

Determining the right candidate as an envoy to take part in a quiz contest can increase the chances of becoming a champion. To achieve these opportunities the school must be more selective in choosing the students who excel in the subjects to be contested. In the selection of students, intelligent representatives are usually the school only takes students who get the first rank of each class, even though it is not necessarily that the students master the lessons to be contested. Can help Senior High School 1 Sungai Aur in making quick and accurate decisions for the selection of representatives of quiz competition. Data obtained from the Senior High School 1 Sungai Aur in the form of student data with a sample of 20 students who have the potential in their respective subjects. Furthermore, the data will be analyzed using the Profile Matching method. The results of this study, it was decided that only 12 participants from 20 samples were passed. Processing results found that there were 3 participants whose decisions were different from those of the school and 9 participants with the same decision. So that the value of data processing accuracy is 75% and an error value of 25% of the 12 participants determined. It can be concluded that this study can help the school to determine students who have the right to represent their school in a quiz competition.

Tiansi is a company that markets health products. This company has difficulty predicting people's interest in products that are in high demand. By knowing precisely the consumer interest in the product, it will increase sales. The research aims to predict consumer interest in Tiansi products appropriately. The method used is one of the Artificial Neural Network (ANN) techniques, namely Backpropagation with Momentum. The sales data tested were sourced from Stockist 319 Padang. The results of this research that can precisely determine consumer interest are architecture 5-2-1 and 5-3-1. So that this research is very helpful in the procurement of goods to increase the value of sales.