मनोवैज्ञानिक और व्यवहारिक अनुसंधान में, मांग विशेषताओं (demand characteristics) के आधार पर विषय भूमिकाओं या प्रतिभागियों की श्रेणियों के रूप में निम्नलिखित में से किसे मान्यता प्राप्त वर्गीकरण माना गया है? A. अच्छे प्रतिभागी (Good participants) B. नकारात्मक प्रतिभागी (Negative/Negativistic participants) C. वफादार प्रतिभागी (Faithful participants) D. आशंकित प्रतिभागी (Apprehensive participants) E. पारंपरिक प्रतिभागी (Traditional participants) नीचे दिए गए विकल्पों में से सही उत्तर चुनिए:

Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R). Assertion (A): Though ex-post facto research examines cause and effect relationships, it is not part of experimental research. Reason (R): In ex-post facto research, the effect or change in the independent variable has already occurred and cannot be manipulated. In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R). Assertion (A): In non-probability sampling, the units are selected at the discretion of the researcher. Reason (R): Non-probability samples do not require a sampling frame. In the light of the above statements, choose the most appropriate answer from the options given below: