Research 101: Scientific Research Designs

1. Research 101: Research Designs
Harold Gamero

2. Research designs
Definition
It is a comprehensive plan for collecting data in an empirical research project.
• At least three processes must be specified in this plan:
1. For data collection.
2. For the development of instruments.
3. For sampling.

3. Research designs
• In general terms, data collection methods can be of two types:
vs.
• These two approaches should not be confused with quantitative or qualitative methods,
which refer to the type of data to be collected and analysed.
• In both cases, the use of mixed methods is recommended.
Interpretive methods
Aimed at constructing theories based on observed
empirical data
(e.g. action research, ethnography).
Positivist methods
Aimed at testing theories and hypotheses
(e.g. experiments, surveys).

4. Attributes of the research design
Internal Validity
•Verify causality
between variables.
•Requires:
i. Co-variation of
cause and effect.
ii.Time precedence.
iii.Lack of alternative
explanations.
External Validity
•Level of
generalization of the
results obtained with
the method.
•For the entire
population
(population validity).
•For other people and
contexts (ecological
validity).
Construct Validity
•Extent to which the
measurement scale
used measures the
construct it is
expected to
measure.
•Although it is an
attribute of the
instrument, this in
turn depends on the
method to be used.
Validity of
Statistical
Conclusions
•Degree of validity of
conclusions derived
from statistical tests.
•This validity does not
apply to
interpretative
research since there
are no statistical
tests.

5. Attributes of the research design
• Types of validity in scientific research:
Independent
variable
Dependent
variable
Construct A Construct B
Proposals
Hypothesis
Theoretical level
Empirical level
Construct
validity
Construct
validity
External
validity
Internal
validity

6. Attributes of the research design
Source: Bhattacherjee, A. (2012).Social Science Research: Principles, Methods, and Practices.Textbooks Collection, Book 3.

7. Improved internal and external validity
• The best designs are those that present high levels of internal and external validity. These
can be improved through:
• By manipulating the independent variables, extraneous factors can be isolated.
• This is achieved with experimental or quasi-experimental designs.
• Extraneous variables can be kept as constants through their elimination.
• E.g. Studying first males and then females.
• Extraneous variables are included in the investigation and their effects are estimated
separately.
• Extraneous variables are measured and used as control variables or co-variables.
co-variables.
• The subjects in the sample (even if the sample is not randomized) are randomly
assigned to the control and treatment groups.
Manipulation
Disposal
Inclusion
Statistical
control
Randomness

8. Popular research designs
Experimental Designs
• They measure cause and effect relationships in highly controlled environments, temporally
separating both factors.
• The classic design separates two groups, where one receives the cause and the other
does not, and then the differences between the two groups are measured.
• In pure experiments subjects should be randomly assigned to groups.
• In quasi-experiments, subjects are not randomly assigned.
• Experiments can take place in artificial environments (laboratory experiments) or in a
natural environment (field experiments).
• All related factors must be identified and controlled ex ante.

9. Popular research designs
Experimental Designs
Source: Bhattacherjee, A. (2012).Social Science Research: Principles, Methods, and Practices.Textbooks Collection, Book 3.

10. Popular research designs
Survey Designs
• These are non-experimental investigations.
• They record information from individuals through questionnaires or structured interviews.
• In cross-sectional designs both variables (independent and dependent) are measured at
the same time.
• In longitudinal designs, the dependent variable is measured after the independent
variables have been measured.
• Surveys have high levels of external validity, but their internal validity is often affected by
different biases.

11. Popular research designs
Survey Designs

12. Popular research designs
Secondary Data Analysis
• Previously collected information (from reliable sources) is analyzed.
• Effective when the required information is very costly or difficult for the researcher to
collect.
• Possible when information is available.
• Some limitations may be:
➢ Information collected in a non-systematic manner.
➢ That it has not followed scientific procedures.
➢ Variables not always compatible with our constructs (no construct validity).

13. Popular research designs
Case Studies
• In-depth research conducted in real scenarios over long periods of time.
• Data are generally collected through interviews, personal observations and analysis of
internal and external documentation.
• They can be positivist or interpretative.
• Their strength is that they can uncover previously undiscovered factors related to a
problem.
• Its analysis is mainly qualitative, highly contextualized and detailed.
• They may be more generalizable by using multiple case designs.

14. Popular research designs
Case Studies
Source: Bhattacherjee, A. (2012).Social Science Research: Principles, Methods, and Practices.Textbooks Collection, Book 3.

15. Popular research designs
Focus Group Designs
• They involve small groups of people to discuss a given phenomenon.
• Usually at intervals of 1.5 to 2 hours.
• The objective is to understand the problem of interest holistically.
• Its level of validity cannot be measured due to its lack of controls and small sample size.
• With these characteristics, this design is not suitable for explanatory or descriptive
research, but rather for exploratory studies.

16. Popular research designs
Action Research
• It assumes that complex social phenomena are best understood by introducing actions
and observing their effects.
• The actions chosen by the researcher must be supported and based on theory.
• This initial theory is validated according to the degree to which the action taken solves the
problem satisfactorily.
• It is an excellent method that combines research and practice.
• It is subject to some biases and to the subjectivity of the researcher.

17. Popular research designs
Ethnography
• Interpretive design inspired by anthropology.
• It emphasizes that phenomena should be studied in their cultural context.
• It requires the researcher to be immersed in the cultural context for an extended period of time
(from 8 months to 2 years).
• Information is generally collected through observation techniques, formal and informal
interactions with subjects, and personal notes.
• This method is context sensitive, provides a rich and detailed understanding of the phenomenon
and has minimal respondent bias.
• It requires a lot of time and resources and is not extrapolable.

18. Popular research designs
Ethnography
Source: Bhattacherjee, A. (2012).Social Science Research: Principles, Methods, and Practices.Textbooks Collection, Book 3.

19. Selection of the research design
• The design should be chosen according to the nature of the phenomenon to be studied
(ideally).
• Regardless of the design chosen, the researcher should attempt to collect both qualitative
and quantitative data.
The objective of the research should be to collect as much and as diverse information
as possible, which will help to generate the best in-sights of the phenomenon under
study.
!

20. Thank you.
Harold Gamero