Introduction to the quantitative methodology
Vít Gabrhel
vit.gabrhel@mail.muni.cz
vit.gabrhel@cdv.cz
FF MU,
30. 6. 2016
1. Philosophical Standpoint
2. The Role of Theory
3. Methodology
4. Psychometrics
5. Data Analysis
6. Beyond Scientific Method
7. Exercise
(Post-)positivism (Macionis & Gerber, 2010)
Scientific realism (Shapere, 1982)
Scientific Method
Theory, deduction, hypothesis, data collection, induction, acquiring new knowledge or correcting the previous knowledge
Wallace wheel of science (Wallace, 1971)
Empiric Approach (Babbie, 2010)
Scientific knowledge about the world is based on systematic observation
Personal experience, although undoubtedly legitimate, may represent a selective part of the reality
Unsystematic observations may lead to various errors and biases
Inaccurate observations - Most of our daily observations are casual and semiconscious. That's why we often disagree about what really happened.
Overgeneralization - "He is one of them. They are all the same."
Selective observations - Confirmatory bias
Illogical Reasoning - "The exception proves the rule."
Heuristics - Representativity, Anchoring and Adjustment, Availability etc.
Falsification (Popper, 1968)
"How many angels dance on the head of the pin?
Stochastic or Probabilistic Principle (Babbie, 2010)
Every claim has a degree of certainty - an exception does not mean that a pattern does not exist.
This applies for both social and natural sciences (e.g. subatomic physics or genetics are based
on probabilities)
Educational mobility
"There is a tendency to reproduce achieved educational level through the generations."
(e.g. Bourdieu and Passeron, 1977)
Gender differences in salary
"A particular woman may well earn more money than most men, but that provides small consolation to the majority of women, who earn less. The pattern still exists."
"There is nothing more practical than a good theory."
Kurt Lewin
Theory is a systematic explanation for the observations that relate to
particular aspects of life.
It is a model of reality that allows us to understand the reality,
to predict future outcomes based on previous inputs
Scientific theory versus common sense (Babbie, 2010)
Tradition
By accepting what everybody knows, we avoid the overwhelming task of starting from scratch in our search for regularities and understanding.
At the same time, tradition may hinder human inquiry. Moreover, it rarely occurs to most of us to seek a different understanding of something we all "know" to be true.
Authority
We benefit throughout our lives from new discoveries and understandings produced by others. Often, acceptance of these new acquisitions depends on the status of the discoverer. We're more likely to believe that the common cold can be transmitted through kissing, when you hear it from an epidemiologist than when you hear it from your uncle Pete.
The advertising industry plays heavily on this misuse of authority by, for example, having movie actors evaluate the performance of automobiles
Example
The affect component reflects one's personality, e.g. through one's preference for individual or group work.
Learning styles represent such setting of individuals that allow them to receive, proceed, store and restore contents that they try to learn to the most effective extend (James & Blank, via James & Gardner, 1995).
As such, learning styles comprise of cognitive, sensual and affect components or dimensions.
Student Styles Questionnaire is inspired by the Psychological types of C. G. Jung and Myers-Briggs Type Indicator (MBTI)
Extraverted-Introverted
Seeking company of others versus preference for one's own internal world
Practical-Imaginative
Interested in facts versus imaging possibilities
Thinking-Feeling
Information analysis and critical approach versus deciding upon one's personal standards
Organized-Flexible
Preference of structure and plan versus preference of open state of things
External validity and the studied sample
Who/What are we trying to observe?
Importance of the external validity of the results
If the sample differs from the population in a key characteristic, we can't generalise the results on the population
Importance of the internal validity of the results
If there is a specific sub-sample is with a key characteristic that differs from the overall sample, the results may be caused not by our measurement, but by this specificity.
Sampling procedures
Probabilistic
Random simple, Stratified, Cluster, Multi- staged, Random walk, etc.
Non-probabilistic
Convenient, Snowball, Quota, Opinion poll, etc.
Construct validity and the used method
What procedures do we use in order to measure our latent variables?
Research design
Experimental - We are looking for causality
Correlational - We are looking for association
Research tools
Experimental manipulations - instruction, incentive etc.
Questionnaire - items on subjective (attitude scales such as Likert, Thurnstone, Guttman, Semantic Differential, Q-sort, etc.) and objective (socio-demographics) topics
Unobtrusive research - observation, content analysis, analysing existing statistics, physical footprints etc.
Internal validity and the design of the study
Threats to the internal validity
History, maturation, reactivity, selection bias, etc.
How certain we could be about our results?
Internal validity stands for the degree of our certainty that the results are a product of our research and not of some unobserved phenomena.
It is especially important for experimental research designs.
Example
Non-probabilistic sampling - convenient sample
N = 520 (36 % Females)
Age: M = 17,3 (SD = 1,4)
Variety of study programmes: 9 schools, more than 20 classes
Questionnaire as a method of data collection
Reliability
How accurately do we measure what we want to measure?
Is our measurement consistent?
How accurately do we measure over time?
Does our method have a parallel?
Validity
What do we measure?
How plausibly did we capture the concept?
Content validity - Is the content of the method aligned with the theory?
Factor validity - Does the obtained factor structure reflect the theoretical assumptions?
To what degree the concept relates to other concepts?
Predictive validity - Does the variable help us to predict some phenomena based on the theory?
Concurrent validity - Is the variable aligned with other variables relevant according to the theory?
Incremental validity - Does one method assessing cognitive abilities explain something more in comparison to the different method assessing cognitive abilities?
Differential validity - To what degree is some variable (e.g. cognitive ability) different from the other, unrelated variable (e.g. personality trait)?
Example
Reliability
Validity
The Czech context
Extroverted-Introverted – 23 items, 445 participants, KR20 = 0.82
Practical-Imaginative – 16 items, 454 participants, KR20 = 0.50
Thinking-Feeling –10 items, 480 participants, KR20 = 0.58
Organized-Flexible – 26 items, 451 participants, KR20 = 0.62
Authors of the method argue that reliability in terms of internal consistency is not a suitable indicator of reliability, especially because of dichotomic nature of items and their limited number. According to them, this fact could undermine the internal consistency of SSQ as it is a short questionnaire (Oakland et al., 1996).
Procedures
Were the chosen analytical procedures able to answer the research question/problem? Were they correctly used? Were their limits reflected?
Statistical significance and other indicators
Did authors rely on arbitrary criteria such as statistical significance or did they also used other needed information, e.g. size effects?
Interpretation
Is the interpretation of the results aligned with the data? Is there any exaggeration?
Normative versus descriptive nature of the science
"Scientific theory-and, more broadly, science itself-cannot settle debates about values. Science cannot determine whether capitalism is better or worse than socialism. What it can do is determine how these systems perform in terms of some set of agreed-on criteria. For example, we could determine scientifically whether capitalism or socialism most supports human dignity and freedom only if we first agreed on some measurable definitions of dignity and freedom. Our conclusions would then be limited to the meanings specified in our definitions. They would have no general meaning beyond that." (Babbie, 2010, p. 11)
Ethics
Research Methodology
Schutt, Russell K. 2004. Investigating the Social World. The Process and Practice of Research (4th ed.). Thousand Oaks: Pine Forge Press.
BLAIKIE, N. 2000. Designing Social Research. Cambridge: Polity.
Ridenour, C. S., Newman, I. (2008). Mixed Methods Research. Exploring the Interactive Continuum. Carbondale: Southern Illinois University Press
Statistics
Morgan, S. E., Reichert, T., Harrison, T. R.: From numbers to words. Reporting statistical results for the social sciences. Allyn & Bacon, 2002.
Howell, David C. [DH] Statistical methods for psychology. 8th ed. Belmont, CA: Wadsworth Cengage Learning, 2013
Field, A.: Discovering statistics using SPSS/R/SAS/etc.
Psychometrics
Furr, R. M., & Bacharach, V. R. (2014). Psychometrics : An Introduction, 2nd ed. Los Angeles: Sage.
Philosophy
Borsboom, D. (2005). Measuring the Mind. Cambridge: Cambridge University Press.
Chakravartty, A. (2015). Scientific Realism. In Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/archives/fall2015/entries/scientific-realism Monton, B., & Mohler, C. (2014). Constructive Empiricism. In Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/archives/spr2014/entries/constructive-empiricism Chang, H. (2009). Operationalism. In Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/archives/fall2009/entries/operationalism