Quantitative research methods Flashcards
What is an independent variable (IV)?
The variable that the research manipulates.
Example: In a study testing whether consuming ‘sugar’ improves memory, ‘sugar’ is the IV.
What is a dependent variable (DV)?
The variable that the researcher measures.
Example: In the sugar and memory study, the DV is ‘memory’.
What does it mean to operationalise a variable?
To state the variable in more specific, measurable terms.
How can the IV be operationalised?
In terms of how it is going to be manipulated.
How can the DV be operationalised?
In terms of how it is going to be measured.
What characterizes standardised experiments?
Procedures are written in enough detail to be replicated by another researcher.
What is a true experiment?
An experiment that randomly allocates participants to the conditions of the study.
What is a control condition?
The absence of any IV, serving as a baseline.
What are experimental conditions?
The presence of IV, used for comparison.
What is an experimental hypothesis (H1)?
A prediction of how the IV will affect the DV.
What is a null hypothesis (H0)?
States that the IV will have no effect on the DV or that any change in the DV will be due to chance.
Provide an example of a null hypothesis.
Consuming one Mintie will have no significant effect on adolescents’ ability to recall words from a list of 15.
What is a one-tailed hypothesis?
Predicts an effect in one direction.
Provide an example of a one-tailed hypothesis.
Consuming sugar will increase one’s recall.
What is a two-tailed hypothesis?
Predicts an effect in either direction.
Provide an example of a two-tailed hypothesis.
Consuming sugar will have an effect on one’s recall.
What are quasi-experiments?
Experiments with participants grouped based on a trait or behaviour.
What is a natural experiment?
A subset of quasi-experiments using an IV that is naturally occurring.
What are extraneous variables?
Variables other than the IV that may influence the DV.
What happens if extraneous variables are not minimized?
They become confounding variables.
What is the main limitation of quasi-experiments?
They do not show direct causation due to lack of random allocation.
What is ‘internal validity’?
The extent to which a study accurately establishes a causal relationship between the IV and DV.
What are demand characteristics?
Participants act differently simply because they know they’re in a study.
What is the expectancy effect?
The participant attempts to discern the experimenter’s hypotheses to help the researcher.
What is the screw you effect?
The participant attempts to discern the experimenter’s hypotheses to undermine the study’s credibility.
What is the social desirability effect?
Participants answer in a way that makes them look good to the researcher.
What is researcher bias?
Expectations of the researcher consciously or unconsciously affect the findings of the study.
How can a double-blind procedure help in research?
It prevents both participants and the researcher from knowing the aim of the study or group assignments.
What is participant variability?
Characteristics of the sample may affect the dependent variable.
What methods can minimize participant variability?
Random sampling and/or random allocation.
What does artificiality refer to in experiments?
The situation of the experiment is unlikely to occur in reality, raising questions of ecological validity.
What is a correlation?
The measurement of the extent to which pairs of related values of two variables tend to change together.
What is a positive correlation?
If one variable increases, so does the other.
What is a negative correlation?
If one variable decreases, the other increases.
What is a curvilinear relationship?
One variable increases, so does the other, but only up to a certain point, after which the other decreases.
What is a correlational study?
Collecting data to determine if there is a statistical relationship between variables without manipulating the IV.
When are correlational studies typically used?
When an experiment cannot be conducted.
What is the difference between experimental and correlational research?
Experimental research tests cause-and-effect relationships; correlational research studies associations without manipulation.
What is an independent variable?
The variable that is manipulated in an experiment.
What is a dependent variable?
The variable that is measured in an experiment.
What is high internal validity?
Allows conclusions to be made about causality.
What is high external validity?
The ability to generalize conclusions to other populations or settings.
What is a survey?
A set of questions and the process of collecting, aggregating, and analyzing the responses.
What types of data can surveys involve?
Quantitative and qualitative data, or just quantitative.
What is a Likert Scale?
A rating scale used in surveys for closed questions.
What is an independent measures design?
Members of the sample are randomly allocated to one condition of the experiment.
What are the strengths of an independent measures design?
- No order effects
- Same materials can be used for all conditions
- Less time-consuming
What are the limitations of an independent measures design?
- Participant variability may influence results
- More participants are required
What is a repeated measures design?
One sample of participants is exposed to all conditions of the experiment.
What are the strengths of a repeated measures design?
- Participant variables are controlled
- Fewer participants are needed
What are the limitations of a repeated measures design?
- Participants may demonstrate order effects
What is a matched pairs design?
Members of the sample are pre-tested regarding a variable deemed important for the experiment.
