There are two categories of research methods: qualitative and quantitative. Quantitative data collection usually involves numbers, graphs and charts, whereas, qualitative data collection methods deals with feelings and other non-quantifiable elements.
Questionnaires can be used as qualitative, as well as, quantitative method. Specifically, if open-ended questions are used qualitative methods will be used for data analysis. Alternatively, if questionnaire consists of closed-ended questions, then quantitative approach is adopted for data analysis.
Differences between Qualitative and Quantitative Methods
The main differences between qualitative and quantitative research methods can be summarised in the following points:
Firstly, the concepts in quantitative research methods are usually expressed in the forms of variables, while the concepts in qualitative research methods are expressed in motives and generalisations.
Secondly, quantitative research methods and measures are usually universal, like formulas for finding mean, median and mode for a set of data, whereas, in qualitative research each research is approached individually and individual measures are developed to interpret the primary data taking into account the unique characteristics of the research.
Thirdly, data in quantitative research appears in the forms of numbers and specific measurements and in qualitative research data can be in forms of words, images, transcripts, etc.
Fourthly, research findings in quantitative research can be illustrated in the forms of tables, graphs and pie-charts, whereas, research findings in qualitative studies is usually presented in analysis by only using words.
Commenting on the differences of the qualitative methods from the quantitative methods Monette et al (2005, p.428) point to the advantage of the former method which recognizes the abstraction and generalisation as a matters of degree, acknowledging that they may be less important in some studies.
Similarities of both qualitative and quantitative forms of data are drawn by Neuman (2003, p.439) as a use of inference and the involvement of a public method of process for both types of data in both styles.
The following table presents the main differences between qualitative and quantitative research methods as suggested by VanderStroep et al (2010):
|Characteristic||Quantitative research||Qualitative research|
|Type of data||Phenomena are described numerically||Phenomena are described in a narrative fashion|
|Analysis||Descriptive and inferential statistics||Identification of major schemes|
|Scope of inquiry||Specific questions or hypotheses||Broad, thematic concerns|
|Primary advantage||Large sample, statistical validity, accurately reflects the population||Rich, in-depth, narrative description of sample|
|Primary disadvantage||Superficial understanding of participants’ thoughts and feelings||Small sample, not generalisable to the population at large|
Source: VanderStroep et al (2010)
Alternatively, the main differences between qualitative and quantitative research tools are provided by Ledgerwood and White (2006) as taken from Brand (2003) in the following table.
|Method matrix||Qualitative research||Quantitative research|
|Objective||To gain in-depth understanding of consumers’ attitudes and behaviour||To measure the degree and extent of the attitudes|
|Confidence level||Explorative, anecdotal||Conclusive, with a specified degree of certainty|
|Techniques||Unstructured or semi-structured||Structured|
|Tools||Focus groups, in-depth interviews, mystery shoppers||Simple and complex surveys, database analysis (cross tabulation)|
|Participants||Small and homogeneous groups||Samples with a statistical representation of the population|
|Results||Words and descriptions||Codified results, compiled as statistics|
|Training and preparation||Understanding objectives of the study||Consistency and precision of questions usedComputer analysis|
|Strengths||In-depth exploration of questionsBetter understanding of underlying behavioursUsually can implement with staff||Conclusive; its results can be inferred to the rest of the populationBetter for costly investment because it measures degree and frequency of behaviours|
|Weaknesses||Subjective; bias can be introduced in the execution and analysis of resultsNot conclusive; research cannot be inferred to the population||Bias on the form and the questionnaireCan be costly and time consumingUsually implemented by outside marketing research firms|
Cohen et al (2007), and Denscombe (2010) illustrate the main differences between qualitative and quantitative research methods:
|Quantitative methods||Qualitative methods|
|Main elements||Numbers, formulas, calculations||Words, feelings, emotions, sounds, vision|
|Approach||Mainly deductive||Tend to be inductive|
|Measures||Standard measures exist||Individual measures are created taking into account unique aspects of the study|
|Procedures||Research procedures tend to be standard and can be replicated for other studies||Research procedures are unique for each study and usually can not be replicated|
|Presentation||Tables, graphs, charts, and statistics are often used||Presentations tend to be in the form of texts|
|Relevant data collection methods||Survey||Interviews, focus groups|
|Size of the sample||Usually large samples||Tend to be small|
Denscombe, M, 2004, The Good Research Guide for small-scale social research, 2nd edition, Open University Press.
Monette, DR, Sullivan, TJ, DeJong, CR, 2005, Applied Social Research. A Tool for the Human Services, 6th edition
VanderStroep, S.W & Johnson, D.D. (2010) “Research Methods for Everyday Life: Blending Qualitative and Quantitative Approaches” John Wiley & Sons