HOW TO CHOOSE FROM THE DIFFERENT RESEARCH METHODS*
The design is the structure of any scientific work. It gives direction and systematizes the research. The method you choose will affect your results and how you conclude the findings.
Most scientists are interested in getting reliable observations that can help the understanding of a phenomenon.
There are two main approaches to a research problem: In a nutshell, quantitative research generates numerical data or information that can be converted into numbers. Qualitative
Research on the other hand generates non-numerical data. It focuses on gathering of mainly verbal data rather than measurements. Gathered information is then analyzed in an interpretative manner, subjective, impressionistic or even diagnostic.
The primary aim of a Qualitative Research is to provide a complete, detailed description of the research topic. Quantitative Research on the other hand focuses more in counting and classifying features and constructing statistical models and figures to explain what is observed. Qualitative Research is ideal for earlier phases of research projects while for the latter part of the research project, Quantitative Research is highly recommended.
Selecting the correct type from the different research methods can be a little daunting, at first. There are so many factors to take into account and evaluate. This is before looking at the statistics required, and studying the preferred methods for the individual scientific discipline. Every experimental design must make compromises and generalizations, so the researcher must try to minimize these, whilst remaining realistic. For ‘pure’ sciences, such as chemistry or astrophysics, experiments are quite easy to define and will, usually, be strictly quantitative. For biology, psychology and social sciences, there can be a huge variety of methods to choose from, and a researcher will have to justify their choice. Whilst slightly arbitrary, the best way to look at the various methods is in terms of ‘strength’.
EXPERIMENTAL RESEARCH METHODS
The first method is the straightforward experiment, involving the standard practice of manipulating quantitative, independent variables to generate statistically analyzable data.
Generally, the system of scientific measurements is interval or ratio based. When we talk about ‘scientific research methods’, this is what most people immediately think of, because it passes all of the definitions of ‘true science’. The researcher is accepting or refuting the null hypothesis. The results generated are analyzable and are used to test hypotheses, with statistics giving a clear and unambiguous picture. This research method is one of the most difficult, requiring rigorous design and a great deal of expense, especially for larger experiments. The other problem, where real life organisms are used, is that taking something out of its natural environment can seriously affect its behavior.
It is often argued that, in some fields of research, experimental research is ‘too’ accurate. It is also the biggest drain on time and resources, and is often impossible to perform for some fields, because of ethical considerations. The Tuskegee Syphilis Study was a prime example of experimental research that was fixated on results, and failed to take into account moral considerations. In other fields of study, which do not always have the luxury of definable and
*Information originally sited at http://www.experiment-resources.com/research-designs.html
, http://www.experiment-resources.com/quantitative-and-qualitativeresearch.html
, and http://www.experiment-resources.com/different-research-methods.html
.

quantifiable variables - you need to use different research methods. These should attempt to fit all of the definitions of repeatability or falsifiability, although this is not always feasible.
OPINION BASED RESEARCH METHODS
Opinion based research methods generally involve designing an experiment and collecting quantitative data. For this type of research, the measurements are usually arbitrary, following the ordinal or interval type. Questionnaires are an effective way of quantifying data from a sample group, and testing emotions or preferences. This method is very cheap and easy, where budget is a problem, and gives an element of scale to opinion and emotion. These figures are arbitrary, but at least give a directional method of measuring intensity.
Quantifying behavior is another way of performing this research, with researchers often applying a ‘numerical scale’ to the type, or intensity, of behavior. The Bandura Bobo Doll experiment and the Asch Experiment were examples of opinion based research. By definition, this experiment method must be used where emotions or behaviors are measured, as there is no other way of defining the variables. Whilst not as robust as experimental research, the methods can be replicated and the results falsified.
OBSERVATIONAL RESEARCH METHODS
Observational research is a group of different research methods where researchers try to observe a phenomenon without interfering too much. Observational research methods, such as the case study, are probably the furthest removed from the established scientific method.
This type is looked down upon, by many scientists, as ‘quasi-experimental’ research, although this is usually an unfair criticism. Observational research tends to use nominal or ordinal scales of measurement.
Observational research often has no clearly defined research problem, and questions may arise during the course of the study. For example, a researcher may notice unusual behavior and ask, ‘What is happening?’ or ‘Why?’ Observation is heavily used in social sciences, behavioral studies and anthropology, as a way of studying a group without affecting their behavior. Whilst the experiment cannot be replicated or falsified, it still offers unique insights, and will advance human knowledge. Case studies are often used as a pre-cursor to more rigorous methods, and avoid the problem of the experiment environment affecting the behavior of an organism. Observational research methods are useful when ethics are a problem.
CONCLUSION
In an ideal world, experimental research methods would be used for every type of research, fulfilling all of the requirements of falsifiability and generalization. However, ethics, time and budget are major factors, so any experimental design must make compromises. As long as a researcher recognizes and evaluates flaws in the design when choosing from different research methods, any of the scientific research methods are valid contributors to scientific knowledge.
*Information originally sited at http://www.experiment-resources.com/research-designs.html
, http://www.experiment-resources.com/quantitative-and-qualitativeresearch.html
, and http://www.experiment-resources.com/different-research-methods.html
.

Designs & Techniques Type of Method
Descriptive Research
Description
Observing and describing the behavior of a subject without influencing it in any way.
Case study An in-depth investigation of a single individual, group, or event.
Naturalistic Observation Observing a subject in their natural habitat without any manipulation by the observers. Descriptive Designs
Aim: Observe and
Describe
Survey/ Questionnaire
Series of questions and other prompts for the purpose of gathering information from respondents.
Semi-Experimental
Designs
Aim: Determine Causes
Reviewing Other
Research
Aim: Explain
Field Experiment
Quasi-Experimental
Design
Twin Studies
Literature Review
Meta Analysis
Applying the scientific method to experimentally examine an intervention in the real world.
Involves selecting groups, upon which a variable is tested, without any random pre-selection processes.
Compares the similarity of identical and fraternal twins to help disentangle the relative importance of environmental and genetic influences on individual traits and behaviors.
A body of text that aims to review the critical points of current knowledge including substantive findings as well as theoretical and methodological contributions to a particular topic.
Statistical method of combining the results of several studies that address a set of related research hypotheses.
Provide an exhaustive summary of literature relevant to a research question. Systematic Reviews
Pilot Study
A small scale preliminary study conducted before the main research, in order to check the feasibility or to improve the design of the research.
Test Study Before
Conducting A Full
Scale Study
Aim: Does the Design
Work?
Usability Testing
System Testing
Proof of Concept
A technique used to evaluate a product by testing it on users.
Testing conducted on a complete, integrated system to evaluate the system's compliance with its specified requirements.
A demonstration in principle, whose purpose is to verify that some concept or theory has the potential of being used.
*Information originally sited at http://www.experiment-resources.com/research-designs.html
, http://www.experiment-resources.com/quantitative-and-qualitative-research.html
, and http://www.experimentresources.com/different-research-methods.html
.

*Information originally sited at http://www.experiment-resources.com/research-designs.html
, http://www.experiment-resources.com/quantitative-and-qualitative-research.html
, and http://www.experimentresources.com/different-research-methods.html
.

Type of Techniques
Pretest-Posttest Design
Control Group
Randomization
Usability Testing
Competitor Analysis
Heuristic Evaluation
Hierarchal Task Analysis
Description
Involves randomly assigning subjects between two groups, a test group and a control. Both groups are pre-tested, and both are post-tested, the ultimate difference being that one group was administered the treatment manipulated in some manner. For many true experimental designs, pretest-posttest designs are the preferred method to compare participant groups and measure the degree of change occurring as a result of treatments or interventions.
Scientific control refers to a concept that allows for comparison as a part of the scientific method. It is often used in discussion of natural experiments. For instance, during drug testing, scientists will try to control two groups to keep them as identical and normal as possible, then allow one group to try the drug. This allows science to isolate the effects of the drug. The control group if practically identical to the experimental group in terms of subjects, the experimental group is changed according to some key variable of interest, while the control group remains constant during the experiment.
Involves randomly allocating experimental units across control and experimental groups. A simple random sample is selected so that all samples of the same size have an equal chance of being selected from the population. In statistics, a simple random sample is a subset of individuals (a sample) chosen from a larger set (a population).
A technique used to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system. Usability testing focuses on measuring a human-made product's capacity to meet its intended purpose. Usability testing usually involves systematic observation under controlled conditions to determine how well people can use the product. Examples of products that commonly benefit from usability testing are foods, consumer products, web sites or web applications, computer interfaces, documents, and devices.
An assessment of the strengths and weaknesses of current and potential competitors. This analysis provides both an offensive and defensive strategic context through which to identify opportunities and threats.
Method for computer software that helps to identify usability problems in the user interface design. It specifically involves evaluators examining the interface and judging its compliance with recognized usability principles (the
"heuristics"). Jakob Nielsen's heuristics are probably the most-used usability heuristics for user interface design. They include visibility of system status; match between system and the real world; user control and freedom; consistency and standards; error prevention; recognition rather than recall; flexibility and efficiency of use; aesthetic and minimalist design; help users recognize, diagnose, and recover from errors; and help and documentation.
The analysis of how a task is accomplished, including a detailed description of both manual and mental activities, task and element durations, task frequency, task allocation, task complexity, environmental conditions, necessary clothing and equipment, and any other unique factors involved in or required for one or more people to perform a given task.
*Information originally sited at http://www.experiment-resources.com/research-designs.html
, http://www.experiment-resources.com/quantitative-and-qualitative-research.html
, and http://www.experimentresources.com/different-research-methods.html
.

*Information originally sited at http://www.experiment-resources.com/research-designs.html
, http://www.experiment-resources.com/quantitative-and-qualitative-research.html
, and http://www.experimentresources.com/different-research-methods.html
.