Research Design Basics
dependent variable/what actually changes
Outcome Variable
Doing this allows researchers to measure change over time
Pre test/Post test
Occurs when participants’ responses in the various conditions are affected by the order of conditions to which they were exposed.
Order effects
Every member of the population has an equal chance of selection
Random Sample
The way it was conducted supports the conclusion that the independent variable caused any observed differences in the dependent variable
Internal Validity
We add this extra variable to reduce bias, control for effects, strengthen validity
Placebo
Between groups design can be described as
has different people and different conditions
An effect of being tested in one condition on participants’ behavior in later conditions
Carryover Effect
Measurements using whoever is easy to reach or available
Convenience Sampling
The extent to which a test actually measures the intended construct.
Construct Validity
This variable is changed by the researcher
Independent/Manipulated variable
This quasi experimental design is where participants in two or more groups are measured before AND after treatment/intervention
Nonequivalent Groups Design (Pretest-Posttest)
Where participants perform a task better in later conditions because they have had a chance to practice it
Practice Effect
What is snowball sampling?
having participants connect researchers to similar participants
What is the meaning of external validity?
The way it was conducted supports generalizing the results to people and situations beyond those actually studied
What is the difference between factorial and simple designs?
simple has one IV factorial has more than one
This quasi experimental group is where one group is measured repeatedly before and after an intervention/event to observe changes over time
Interrupted Time Series Design
Participants perform a task worse in later conditions because they become tired or bored
Fatigue Effect
Why would you do a quasi experiment over a true experiment?
The proper statistical treatment of data and the soundness of the researchers’ statistical conclusions.
Statistical Validity
The biggest threat to validity that we need to be aware of to design a good experiment?
Confounds
Two or more nonequivalent groups are measured repeatedly before and after an intervention, allowing comparison between groups over time.
Nonequivalent Groups Interrupted Time Series Design
Being tested in one condition can also change how participants perceive stimuli or interpret their task in later conditions
Context/Contrast Effect
What does BRUSO stand for and what do we use it for?
Brief, Relevant, Unambiguous, Specific, and Objective
How is reliability different from validity
Reliability focuses on the consistency and stability of a measure, while validity focuses on the accuracy and truthfulness of a measure