Ch 2. Research Designs Flashcards
A framework for the collection and analysis of data
Research Design
What is a nomothetic explanation?
Involve attributions of cause-and-effect, expressed in terms of
general laws and principles (typically quantitative)
Nomothetic explanations must satisfy what three criteria of causation?
- Correlation
- Time order
- Non-spuriousness
What is an idiographic explanation?
Involve a rich description of a person or group and seek to explain
the particular (typically qualitative)
Not meant to apply to persons/groups who were not part of the study. Wants to have an empathetic understanding.
What are specific research methods that can be selected once a design is selected?
– Questionnaire
– Structured interview
– Participant observation
– Ethnography
– Experiments
What are four research designs?
- Experimental design
- Cross-sectional design
- Longitudinal design(s)
- Case study design
True experiments are common in psychology and organizational studies but rare in…
…sociology or political science
What are two kinds of experiments?
- field experiments (real-life surroundings)
- laboratory experiments (artificial environments)
Experimental designs are done through the manipulation of variables. What are variables?
characteristics or attributes of data that vary or change (e.g., gender, age, interest in a subject, belief)
What is the difference between an independent variable & dependent variable?
Independent variables are manipulated to see if they have an impact
on dependent variables
What is the difference between experimental/treatment group and the control group?
The experimental or treatment group receives a treatment or
manipulation of some kind while the control group does not get treatment/manipulation
participants are placed in the experimental or control group using a random method
Random assignment
Pre-test (experiment)
measurement of the dependent variable before the experimental manipulation
Post-test (experiment)
measurement of the dependent variable after the experimental manipulation
- Independent and dependent variables are identified
- Dependent variable is observed/measured (pre-test) in control
and treatment groups and recorded at T1 (time 1) - The treatment group receives the treatment while the control group is left alone
- The dependent variable is observed/measured (post-test) in each of the control and treatment groups and recoded as occurring at T2 (time 2)
- Any changes in each group are noted
Classic Experimental Design
True experimental evidence would eliminate what?
all other possible (rival) explanations for the change in the dependent variable in the treatment group
Validity is concerned with…
…the integrity of the conclusions generated by a piece of research. Are we measuring what we want to measure?
Internal validity is concerned with the issue of…
…whether causation has been established by a particular study
- history (some event may have influenced dependent variable)
- testing (pre-test may have influenced dependent variable)
- instrumentation (changes in the way a test is administered)
- mortality
- maturation (participants change over time)
- selection (post-test differences may have been caused by pre-existing differences)
What are some threats to internal validity? (6)
What involves the question “Are you measuring what you want to measure?”
Measurement Validity
External validity has what two primary concerns?
Are the findings applicable to situations outside the research environment?
Can the findings be generalized beyond the people or cases studied?
- the representativeness of the study participants
- the effects of the setting
- history effects
- effect of pretesting
- reactive effects of experimental arrangements (behaving atypically)
What are threats to external validity?
The results remain the same when others repeat all or part of a study and the procedures used to conduct the research are sound and are spelled out
Replicability
What are the benefits and limitations of a laboratory experiment?
Benefits: greater control over the environment as an asset and easier to assign participants randomly to conditions
Limitations: low external validity in a test tube environment
Quasi-experiments differ from true experiments in that…
…internal validity is harder to establish
Involve taking observations at one point in time (no “before” and “after” comparisons). They do not include a manipulation of the independent variable. Two ore more variables are measured to detect patterns of association. One strength of the design is that it can examine the effect of variables that cannot be manipulated in experiments.
Cross-Sectional designs
What are the issues with cross-sectional design?
- establishing internal validity and establishing the direction of causation
- establishing external validity if random methods are not used
Cases are examined at a particular time (T1), and again at a later time or times (T2, T3, etc.) These designs provide information about the time-order of changes in certain variables which helps establish the direction of causation.
Longitudinal Design
What are two basic types of longitudinal designs?
- panel study: the same people studied at different times
- cohort study: people sharing the same experience are studied at different times, but different people may be studied at each time
What are the drawbacks of longitudinal design? (3)
– Attrition over time
– It may be difficult to determine when subsequent waves of the study should be conducted
– Panel conditioning: People’s attitudes and behaviours may change as a result of participating in a panel
Involves an in-depth study of a single case (person, family, organization) and can involve qualitative and/or quantitative research methods. Achieving external validity is not the main purpose. Goal is to provide in-depth descriptions of the characteristics of a particular case that cannot be achieved using other methods
Case Study Design
Types of cases in case study design (2)
- critical case: illustrates the conditions under which a certain hypothesis holds or does not hold
- extreme/unique case: illustrates unusual cases, which help in understanding more common ones
Be able to write a table of the four research designs covered which are:
- experimental
- cross-sectional
- longitudinal
- case study
