The qualities of research design areas follows:
Objectivity: It refers to the findings related to the method of data collection and scoring of the responses. The research design should permit the measuring instrument which is fairly objective in which every observer or judge scoring the performance must precisely give the same report. In other words, the objectivity of the procedure may be judged by the degree of agreement between the final scores assigned to different individuals by more than one independent observer. This ensures the objectivity of the collected data which shall be capable of analysis and drawing generalizations.
Reliability: Reliability refers to consistency throughout a series of measurements. for e.g. if a respondent gives out a response to a particular item, he is expected to give the same response to that item even if he is asked repeatedly. If he is changing his response to the same item, the consistency will be lost. So the researcher should frame the items in a questionnaire in such a way that it provides consistency or reliability.
Validity: Any measuring device or instrument is said to be valid when it measures what it is expected to measure, for e.g., an intelligence test conducted for measuring the I.Q should measure only the intelligence and nothing else, and the questionnaire shall be framed accordingly.
Generalizability: It means how best the data collected from the samples can be utilized for drawing certain generalizations applicable to a large group from which sample is drawn. Thus, a research design helps an investigator to generalize his findings provided he has taken due care in defining the population, selecting the sample, deriving appropriate statistical analysis etc.