Comps - Research Makeup Flashcards
What is the IV?
The variable that is being manipulated
What is the DV?
The variable being measured
What is a covariate?
An additional variable that is secondary to the IV and DV that is being statistically controlled for because it is thought to have some sort of effect on the DV
What is a confounding variable?
A variable other than the independent variable (or treatment) on which the participants in one experimental condition differ systematically from participants in other experimental conditions
What is an extraneous variable?
Any variable other than the independent variable (or treatment) that causes changes in the dependent variable (or outcome)
What is a control group?
The group that is receiving no treatment or a placebo; a group that does not experience any change to the variable being tested
Why is it important to have a control group?
To create a benchmark to compare the experimental results to. It allows for study of the effects of the independent variable alone without confounding conditions. Without a control group, it’s hard to determine whether external factors (e.g., time, maturation) influenced the results
What is the null hypothesis?
There are no differences/relationships found
What is the alternative hypothesis?
There are differences/relationships found
What is power?
The probability that we can reject the null hypothesis (1 - beta)
What does more power do?
Higher power reduces the risk of Type II errors (failing to reject a false null hypothesis)
How can power be increased?
-use homogenous participants
-equal cell sample sizes
-within-participants design
-matching and stratifying
-increase the strength of treatment
-increase the variability of treatment
-larger sample size
-improve measures
-use powerful statistical tests and be sure the assumptions are met
-reduce random setting irrelevancies
-measure and correct for covariates
What is non-random sampling?
A method of selecting a sample from a population where the selection is not based on random chance, but rather on factors like convenience, researcher judgment, or specific characteristics, meaning not every member of the population has an equal chance of being chosen, which can introduce bias
What are the different types of non-random sampling?
Conveniences, snowball, and purposive sampling
What is convenience sampling?
Where participants are selected based on their availability, accessibility, or proximity to the researcher
What is snowball sampling?
Existing participants recruit future participants from their social networks
What is purposive sampling?
-purposive sampling of heterogeneous instances (PSI-Het)
-drawing a sample that captures the range of values present in the population of interest
-the idea is to develop a sample that is really heterogeneous and broad
-purposive sampling of typical instances (PSI-Typ)
-drawing a sample close to the central tendency of the population of
interest
-the idea is the draw a sample that is close to the average/most typical
What is random sampling?
Selects participants for the research on the basis of chance
What are the different types of random sampling?
Simple random, cluster, stratified, disproportionate stratified, and systematic random sampling
What is simple random sampling?
Each member of the population has an equal chance of being selected; research participants are randomly selected from a list of all members of the population of interest
What is cluster sampling?
The population is divided into smaller groups, called clusters, and then individuals are randomly selected from these groups
What is stratified sampling?
It is used when we want to make sure that some characteristic is represented in the sample in the same proportion as it is represented in the population
What is disproportionate stratified sampling?
Used when the strata differ in size and we want to include enough people from each one to allow us to compare the characteristics of the strata
What is systematic random sampling?
A desired sample size is assigned, and then a regular interval number is used to decide who will be sampled