The Nature of Quantitative Research
February 4, 2013
• Quantitative research entails the collection of numerical data, a deductive
(theory- conclusion) relationship between theory and research, a preference for
the natural science approach to research (positivism in particular), and an
objectivist conception of social reality.
• Concepts: ideas or mental representations of things
- E.g.: crime, gender, alienation, gender, life satisfaction
- Concepts may be independent or dependent variables. For example, the
concept ‘social mobility can be used as a possible explanation of certain
attitudes or as something to be explained
• Coding: transforming a measure into numbers
- Can be done in both qualitative and quantitative data
- E.g.: in measuring life satisfaction, respondents who say they are “very
satisfied” may be given a code of “1”, which is then recorded in a file.
- Every data set has a coding manual
Why measure concepts?
- Measurement allows a delineation of small or fine differences between people
or issues we are interested in
- Measurements provide a way to identify and gauge those differences with
- It allows us to estimate what the relationship is between concepts and the
strength of that relationship. What is the correlation? Is it positive or negative?
Two types of definitions for a concept:
• Nominal: describes the concept in words, much like a dictionary definition, E.g.:
political party identification refers to a party to which people most closely
• Operational: describes how the concept is to be measured. E.g.: political party
identification may be measure by asking people, “do you normally think of
yourself as a supporter of the Conservatives, Liberals, NDP, or Bloc Québécois?
• Indicators tell us (indicate) that there may be a link and tell us how strong the
link may be
• Usually, one indicator for each concept is adequate
• It is advantageous to use more than one indicator of a concept (often done in
survey research) because it: - Reduces the likelihood of misclassifying some people because the language
of a question is misunderstood
- Ensures the definition of the underlying concept is understood correctly
- Gets access to a wider range of issues related to the concept, allows the
researcher to make finer distinctions, and
- Allows factor analysis (the process of sorting out the degree to which a
particular concept is being measure and by which indicator)
- E.g.: employee moral; how much does one love his or her job? Can look
at attendance, can be an indication of how much one likes their job
Dimensions of Concepts
- in developing a measure for a concept, its different aspects should be considered
• 1. Reliability: ultimately refers to stability of a measure over time, i.e.: whether
one would get the same result after using a measure at two different times
(assuming no change in what is being measured).
- Stability can be measured using the test- retest method.
- It is extremely difficult to quantify stability over time because of the number
of factors that may come into play over the passage of time, including the fact
the respondents took a prior or pre-test and that may influence subsequent
tests; more stable if done with different groups in different times.
• 2. Internal reliability/ internal consistency: are multiple measures administered
in one sitting consistent with each other, e.g., multiple measures of “life
satisfaction” on a survey.
- This can be measured using Cronbach’s alpha coefficient or the split- half
method. These calculations are done using statistical programs.
- Acorrelation of .8 or higher on a scale of ‘0-1’is generally accepted as a
minimum of internal reliability, although results with lower figures may still
be used by some researchers.
• 3. Inter- observer consistency: all observers should classify behaviors or
attitudes the same way
- e.g.: if two observers are recording the amount of aggression children
display on a playground, their estimates should agree
• Measurement validity: concerned with whether one is measuring what one wants
- There are various kinds of measurement validity:
1. Face validity: is established if, at first glance, the measure appears to be
valid. Ask for the opinion of someone with expertise in the area of study
2. Concurrent validity: is established if the measure correlates with some
criterion thought to be relevant to the concept.Alack of correlation beings
some doubt onto the validity (correctness) of the original measures
- E.g., if IQ scores correlate as expected with grades in university, concurrent
validity is established 3. Construct validity: is established if the concepts relate to each other in a
way that is consistent