I personally don't think the language of "paradigms" is all that useful here. When Guba and Lincoln began promoting the concept of paradigms, they were explicit that it was not about qualitative or quantitative methods, instead they based their paradigms on ontology, epistemology, and methodology. So their version of a paradigm is incompatible with separating methods into qualitative, quantitative, or mixed.

Shifting the question to how new or innovative mixed methods is, I would say that most of the research in that field uses fairly standard approaches to collecting and analyzing both qualitative and quantitative data. What is most likely to be new (and most likely to be challenging) is integrating the results from the different methods.

As a community psychologist who uses mixed methods for program evaluation, I have different perspectives on the question under discussion. Both qualitative and quantitative approaches seek information but do so in different ways. In Qualitative approaches, information or data is obtained via conversations, observations, documents or audiovisual material. These sources of information are descriptive and not easily quantifiable. Methods used to collect these types of information include: focus groups, interviews, participant observations, non-participant observations, and photo-voice. The gold standard of qualitative data is “think, rich descriptions” (Creswell, 2007). Quantitative information represents the world of data that can be easily measured, and has long been considered the “better,” “more accurate,” or “more scientific” way of assessing a program of phenomenon. With quantitative approaches, researchers decide what they want to measure, how they plan on measuring it, and to what criterion they will hold the results. 

Advantages to qualitative approaches to program evaluation include giving voices to everyone involved, including the recipients of services, in a way that can be empowering. Qualitative approaches can provide real insight into a program, and how the program was experienced by staff, recipients, and the community, in a way that quantitative methods cannot. Qualitative approaches, however, often take more time to conduct. They require intensive time in the field collecting data, and in the data analysis process. While qualitative approaches accept that subjectivity on the part of the researcher cannot be avoided, this is often seen as a drawback of qualitative approaches. 

I personally don't think the language of "paradigms" is all that useful here. When Guba and Lincoln began promoting the concept of paradigms, they were explicit that it was not about qualitative or quantitative methods, instead they based their paradigms on ontology, epistemology, and methodology. So their version of a paradigm is incompatible with separating methods into qualitative, quantitative, or mixed.

Shifting the question to how new or innovative mixed methods is, I would say that most of the research in that field uses fairly standard approaches to collecting and analyzing both qualitative and quantitative data. What is most likely to be new (and most likely to be challenging) is integrating the results from the different methods.

Mixed method is not a new appraoch in research. It is usefull in some studies to validate the outcome,  The integration between the two methods could provides a better understanding of a new topic, or in a new setting, May be some researchers consider it 2 studies in one..

Mixed methods is not new in research one can use quantitative or qualitative research a lickert scale as a method of measuring a survery where people me either agree or disagree with  what is being asked or that you are seeking to find out one may carry out an ethnographic study by living with a tribe or cultural group in order to get insight to a way of life. When you select two different research methods then it's called mixed method research. Again deciding on a mixed method may be done to reinforce you results or finding by graphic or charting answers to question in order to back up and give strength to your result finding or reinforce a particular point.of view.

Before one gets to what methodology to be used, it is necessary that a scholar should have well formulated simple questions about what he or she wants to investigate. This could be hypothesis or hypothesis based on ones observation of the phenomena or phenomenon, or based on earlier studies and their results or based on area of problem -- if the problem to complex, it need to be toned down to simple steps and the scholar can choose facet of the problem to investigate. Once this is settled, the scholar should have to have an idea of what variables or data to be called for the problem or questions. Depending upon what variables one should collect data either it is measurable or observational or qualitative aspects. This will lead to appropriate statistical method  useful for the data structure. For example, in a majority of the social sciences research and the problem that are being investigated, in general, involves data variables of both qualitative and quantitative types, accordingly one need to use both qualitative and quantitative methods for the purpose. It is also possible there are certain variables, the data pertaining it to may be obtained both qualitatively and quantitatively, and one can use both the methods for the variable as well.  

I do not think that the Mixed Methods are a new paradigm at this time. The researchers are interested in find new designs capable of  working with quantitative and qualitative data in the evaluation research field (health, education, social interaction, development,...). As Cook and Reichardt (1982) wrote about the methodological complementary, the problem  should not  be raised on the level of paradigm... Is It possible a turn in future?

In research with mixed methods (IMM) theory can be deductive or inductive as an emerging or standard theory. The use of the theory depends on the IMM emphasis on qualitative or quantitative methods. From the "transformative project" to the paradigm transformer / emancipatory, the IMM is identified with process-oriented action and especially for values, as in feminist studies, ethnic / racial and people with disabilities, emancipatory and groups marginalized.

Creswell points clues to use the theory in mixed methods: i) decide whether the theory should be used ii) identify its use respecting the qualitative or quantitative techniques, ii) when used as an investigative strategy transformation, set this strategy and discuss the points where the emancipatory ideas will be used in the proposed study (p. 139). The use of IMM to introduce qualitative data in a quantitative study, or vice versa, to allow the integration of two different methodologies of nature, where both maintain their intrinsic qualities, requires training and as many methodological care and resources.

See Creswell, J. W. (2003). The Use of Theory. In J. W. Creswell. Research Design. Qualitative, Quantitative, and Mixed Methods Approaches (3ª ed., pp.119-141). Thousands Oaks, CA: SAGE.

I personally do not think mixing quantitative and qualitative methods is new in academics. The novelty will be in the approach used. For instance, sequential, or explanatory, and even how you triangulate the data

I do not believe that mixed methods are new in academia. However, they can be useful for gaining more information and insight than the use of one method alone. 

Creswell and  Plano Clark defined mixed methods research as:

“A research design with philosophical assumptions as well as methods of inquiry. As a methodology, it involves philosophical assumptions that guide the direction of the collection and analysis of data and the mixture of qualitative and quantitative approaches in many phases of the research process. As a method, it focuses on collecting, analysing, and mixing both quantitative and qualitative data in a single study or series of studies. Its central premise is that the use of quantitative and qualitative approaches in combination provides a better understanding of research problems than either approach alone” (Creswell & Plano Clark, 2007 p. 5)

With this definition in mind, the researcher is required to:

In this way a researcher can gain greater insight and understanding by triangulating data on a single research topic.

However, mixed methods can be a daunting undertaking both in terms of time and resources.

If you intend to use mixed methods, it can be useful to have a clear research question and a plan for your research based on this. 

This is the best resource for designing a mixed methods approach:  Creswell, John W., and Vicki L. Plano Clark. "Designing and conducting mixed methods research." (2007).

It may not be appropriate to call it a new paradigm. But, mixed research method might help to validate results obtained from a quantitative study. It is not necessary that we need to follow a mixed method research. It would depend on the research questions and the prior work carried out in the research domain. It definitely helps if one could use mixed method research to corroborate the results obtained from either quantitative or qualitative approaches.

Is mixed research method a new paradigm in the academics?

Actually mixed method is not new whereby many academicians / researchers had embarked on such method.

In essence, what are the concepts, patterns, merits and demerits of mixed research method?

You can refer to the following RG link whereby some are good books:

https://www.researchgate.net/post/What_are_the_best_books_authors_to_consult_in_order_to_get_more_than_a_fair_understanding_of_mixed_method_research/1

https://www.researchgate.net/post/Quantitative_vs_qualitative_vs_mixed_can_anybody_help_me_selecting_the_right_research_approach/1

Also according to Onwuegbuzie & Johnson (2004), some possible shortcomings of Mixed Method Design include:

Also was informed some universities are facing the challenges to find the right PhD thesis examiners that are expert in the particular subject domain as well as familiar with mixed method research.

First, I disagree that there is such a thing as either a qualitative or a quantitative paradigm, since those terms apply to methods rather than anything in the traditional philosophy of science. That certainly was not Guba and Lincoln had in mind when they introduced this version of paradigms to the social sciences.

Second, many mixed methods researchers reject the traditional trilogy of ontology, epistemology, and methodology in favor of pragmatism (or in some cases, critical realism) as a paradigm. Since pragmatism was not applied to social science methods until it was promoted by mixed methods researchers, it is in some sense a "new" paradigm.

Also, axiology is not a traditional element of the philosophy of science, since it concerns ethical issues -- although some social scientists have added it to ontology, epistemology, and methodology as a way to get ethics into the picture. 

Here are two of my publications on this topic.

Article Paradigms Lost and Pragmatism Regained: Methodological Impli...

Article Pragmatism as a Paradigm for Social Research

According to Thomas Kuhn (Structure of Scientific Revolutions, 1962), a scientific paradigm can be defined as ‘universally recognised scientific achievements that, for a time, provide model problems and solutions for a community of practitioners’.  Advocates of mixed methods research may indeed hope that their methodological work becomes paradigmatic, but it will be down to a broader community of social scientists as to whether that is indeed the case. 

I would suggest you take a look at Jennifer C. Greene’s paper: ‘Is Mixed Methods Social Inquiry a Distinctive Methodology?’ (Journal of Mixed Methods Research, 2008, Vol. 2 No. 1, pages 7-22.  This examines the claims of mixed methods researchers, and explores a number of research paradigms and how they handle mixing methods.  Note that these paradigms are not about methods however, they are about ontologies and epistemologies of research.

My own view is that we need an ontology of research that can assess what different methods actually do, in order that we can decide how to combine them.  For my analysis of this, see the attached paper: Fox, N.J. and Alldred, P. (2015) Inside the research-assemblage: new materialism and the micropolitics of social inquiry.  Sociological Research Online, 20(2): 6. http://www.socresonline.org.uk/20/2/6.html

Best wishes

Nick

A mixed research method could not be considered as research paradigm but as an instrument to validate  qualitative and quantitative research  methodology. 

I really do appreciate all the criticisms and comments received from the question I asked. They have further exposed me to other areas in research methodology.