What is a variable in user studies and research?
A variable is any situation, behavior, condition, event, or characteristic to be studied and measured.
What is the difference between a sample and a population?
The population is the collection of people from whom researchers draw a sample, and researchers generalize their results to the entire population;
The sample is the subset of individuals actually studied.
What is a theory?
An explanation that coherently organizes separate pieces of information.
What makes research scientific?
Research should be replicable (it can be repeated and provide the same
results), falsifiable (expressed in such a manner
that makes it possible for it to be rejected), precise (with operational definitions), and parsimonious (favoring the simplest logical explanation).
What is a replicable study?
One that can be repeated by others and yield the same results.
What does it mean for a hypothesis to be falsifiable?
It must be possible to prove the hypothesis wrong with evidence or data.
What is an operational definition?
A clear, measurable definition of a variable, such as “number of smiles per hour” to quantify happiness.
What is parsimony (Occam’s razor) in research?
Favoring the simplest explanation that accounts for observed phenomena and helps generalize results.
What does correlation measure?
The strength and direction of the relationship between two variables, with coefficients from -1 to +1.
Does correlation imply causation?
No, two variables can be correlated without one causing the other.
What is positive correlation?
As one variable increases, the
other does too
What is negative correlation?
As one variable increases, the other one decreases
What is reliability in research?
The consistency of a test, survey, or measure over repeated trials or alternate forms.
What are content and criterion validity?
Content validity: measures all aspects of the target characteristic; criterion validity: predicts another related outcome (like SAT scores and GPA).
What is an independent variable?
The variable intentionally manipulated by the researcher during an experiment.
What is a dependent variable?
The variable measured to observe effects from changing the independent variable.
What is a control group, and why is it important?
A control group does not receive the experimental manipulation, serving as a comparison to assess the treatment effect.
What are extraneous variables?
Uncontrolled variables that might affect the dependent variable alongside or instead of the independent variable.
What is random assignment?
Placing subjects into experimental or control groups by chance, helping ensure the groups are similar and reducing bias.
What is sampling bias?
A bias introduced when the sample does not correctly represent the population.
What is subject bias (placebo and social desirability)?
Subject bias occurs when participants’ expectations or desire to present themselves favorably influence results.
What is experimenter bias?
When researchers’ expectations, preferences, or behavior influence study results.
What are single-blind and double-blind designs?
Single-blind: subjects don’t know their group; double-blind: both subjects and experimenters don’t know, reducing bias.
