Quantitative and Qualitative Data

Some methods provide data which are quantitative and some methods data which are qualitative.  Quantitative methods are those which focus on numbers and frequencies rather than on meaning and experience. Quantitative methods (e.g. experiments, questionnaires and psychometric tests) provide information which is easy to analyse statistically and fairly reliable.  Quantitative methods are associated with the scientific and experimental approach and are criticized for not providing an in depth description.
Qualitative methods are ways of collecting data which are concerned with describing meaning, rather than with drawing statistical inferences.  What qualitative methods (e.g. case studies and interviews) lose on reliability they gain in terms of validity.  They provide a more in depth and rich description.
Quantitative methods have come under considerable criticism.  In modern research, most psychologists tend to adopt a combination of qualitative and quantitative approaches, which allow statistically reliable information obtained from numerical measurement to be backed up by and enriched by information about the research participants' explanations.
You will find that many of the core studies do collect both types of data.

Examine the differences between qualitative and quantitative data.
Qualitative Data
Quantitative Data
  • Deals with descriptions.
  • Data can be observed but not measured.
  • Colors, textures, smells, tastes, appearance, beauty, etc.
  • Qualitative → Quality
  • Deals with numbers.
  • Data which can be measured.
  • Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc.
  • Quantitative → Quantit
1.    Qualitative research
Research generated outside the framework of a quantitative approach. Collected data is not subjected to formulaic analysis for the purpose of generating projections.
Qualitative research is a method of inquiry employed in many different academic disciplines, traditionally in the social sciences, but also inmarket research and further contexts.[1] Qualitative researchers aim to gather an in-depth understanding of human behavior and the reasonsthat govern such behavior. The qualitative method investigates the why and how of decision making, not just whatwherewhen. Hence, smaller but focused samples are more often needed than largesamples.
n the social sciencesquantitative researchrefers to the systematic empirical investigation of social phenomena via statistical, mathematical or computational techniques.[1] The objective of quantitative research is to develop and employmathematical modelstheories and/or hypothesespertaining to phenomena. The process ofmeasurement is central to quantitative research because it provides the fundamental connection between empirical observation and mathematical expression of quantitative relationships. Quantitative data is any data that is in numerical form such as statistics, percentages, etc..[2] In layman's terms, this means that the quantitative researcher asks a specific, narrow question and collects numerical data from participants to answer the question. The researcher analyzes the data with the help of statistics. The researcher is hoping the numbers will yield an unbiased result that can be generalized to some larger population.Qualitative research, on the other hand, asks broad questions and collects word data from participants. The researcher looks for themes and describes the information in themes and patterns exclusive to that set of participants.
2.      Quantitative research 
Definition: A method of advertising research that emphasizes the quality of meaning in consumer perceptions and attitudes; for example, in-depth interviews and focus groups.
Quantitative research relies primarily on numbers as the main unit of analysis. It is more commonly used as a primary method in scientific and clinical research, such as drug trials or laboratory experiments where tests may need to be repeated many times, for example to ensure that a new drug is safe. Although quantitative methods, such as surveys, are used in educational research, the vast majority of research is relatively small scale, intensive, focused on change and involves human perceptions. Educational research relies much more heavily on qualitative methods. One of the most common instruments to gather numerical data in education (particularly in evaluation of programmes) is the questionnaire survey, using a series of closed questions to which responses are given against a Likert or other type of scale. Open questions can also be included to gather richer data. Large amounts of data can be gathered from a wide number of people and the results can be analysed by computer (either by an optical mark reader or through an online survey instrument such as ‘Survey Monkey’), thus making it fairly straightforward to research a large sample of respondents. Survey questionnaires can be given out and collected face to face, sent by post or posted online. If achieving a high response rate is important, then note that the less personal involvement there iswith potential respondents, the lower the response rate. So, typically, online surveys may have a response rate of under 20%, whereas if the questionnaires are given out and collected face to face, you may achieve a very high response rate.  
Qualitative methods range from the classification of themes and interconnections, content analysis, grounded theory and discourse analysis, and reliability and validity are just as important as they are in quantitative analyses. There are computer programs to assist in analysis, and although these might not necessarily save time, they often offer more systematic ways of coding data and identifying connections and themes.