Theoretical models can be rigorous.Logical formLearned from3 sentences. A (teacher education program) can be rigorous.Logical formLearned from3 sentences. Stress can be rigorous.Logical formLearned from3 sentences. An assertion can be rigorous.Logical formLearned from3 sentences. Diets can be rigorous.Logical formLearned from3 sentences. A party can be rigorous.Logical formLearned from3 sentences. Field-testings can be rigorous.Logical formLearned from3 sentences. A (graduate study) can be rigorous.Logical formLearned from3 sentences. (Performance requirements) can be rigorous.Logical formLearned from3 sentences. (Design methodologies) can be rigorous.Logical formLearned from3 sentences. (Governance practices) can be rigorous.Logical formLearned from3 sentences. A (specification work) can be rigorous.Logical formLearned from3 sentences. Systematic reviews can be rigorous.Logical formLearned from3 sentences. Problems can be rigorous.Logical formLearned from3 sentences. Persons can be rigorous in demands of forms of presentation.Logical formLearned from3 sentences.