research methods - exam 4

main effect

refers to the impact of one independent variable on the dependent variable, ignoring the other IVs

factorial designs

experimental setups that involve manipulating two or more independent variables simultaneously to observes their effects on one or more dependent variables

AB design

baseline vs treatment

ABA design

baseline vs intervention vs return to baseline

multiple baseline design

a type of single-case experimental design that assesses the effect of an intervention across different subjects, settings or behaviors without needing to withdraw the intervention

descriptive statistics

organize, summarize, simplify, presentation of data = overall goal to describe data

inferential statistics

generalize from samples to populations, hypothesis testing, relationships among variables = overall goal to make predictions

null hypothesis

assumes there is no difference between groups

research/alternative hypothesis

the population means are not equal

alpha level

the probability required for significance

effect size

strength of effect of a variable (self explanatory)

type 1 error

occurs when we reject the null hypothesis when it’s actually true, a false positive

type 2 error

occurs when we accept the null hypothesis when in the population the research hypothesis is true, a false negative

1 shot case study

single group is observed only once the treatment is started. no baseline. no control group

quasi-experimental design

participants are assigned based on pre-existing groups or non-random criteria (ex: a class of students, a specific hospital, etc)

experimental groups

participants are randomly assigned to groups to balance out possible confounding variables